This old Blog

CNN.com - Study: Australia collided together - Aug 17, 2006

2006-08-18T08:10:00.000-04:00

CNN.com - Study: Australia collided together - Aug 17, 2006

CNN.com - Report: Blue whale ancestor was no gentle giant - Aug 16, 2006

2006-08-16T12:04:00.000-04:00

CNN.com - Report: Blue whale ancestor was no gentle giant - Aug 16, 2006

Yellowstone National Park/Super Volcano

2006-05-15T14:01:00.000-04:00

Cheryl Kalman

Many people visit Yellowstone National Park every year to go hiking, to enjoy the wild life, or to see the famous geysers. What most people don’t know about Yellowstone is that is sits on top of a super volcano.
     The way a super volcano differs from a regular one is first, there is no mountain peak. In a regular volcano when lava pours out and cools it creates a cone which builds up the mountain. If the lava passage is blocked off pressure builds and this causes an eruption. In a super volcano the magma never reaches the surface. Pressure just builds until it melts more rocks which becomes more magma. When the pressure becomes too much the entire surface above the magma chamber is blown off causing an eruption thousands of times larger than normal volcanoes. When these eruptions occur a huge amount of material is thrown out of the volcano, leaving a giant crater called a caldera. The Caldera at Yellowstone is so large it can be seen from space.
     The last time Yellowstone had an eruption of that magnitude was 650,000 years ago. The caldera it left is 53 miles long and 28 miles wide, that’s roughly the size of the Los Angeles Basin. 3,000 square miles were subjected to a flow of pyroclastic material containing 240 cubic miles of hot ash and pumice. Ash was also thrown in to the atmosphere which blanketed most of North America.
     So what would happen if another catastrophic eruption took place today?   Bill McGuire, professor of geohazards at the Benfield Greig Hazard Research Centre at the University College of London said "magma would be flung 50 kilometers into the atmosphere. Within a thousand kilometers virtually all life would be killed by falling ash, lava flows and the sheer explosive force of the eruption. One thousand cubic kilometers of lava would pour out of the volcano, enough to coat the whole USA with a layer 5 inches thick […] the bitter cold of Volcanic Winter to Planet Earth. Mankind may become extinct."
     Many recent events at Yellowstone have caused people to worry about another eruption. First, in August 2003 a high resolution sonar map showed a bulge, 2,000 feet long and 100 feet high at the bottom of Yellowstone Lake. Second, at about the same time, areas that were formerly dry suddenly had hot springs and a long dormant geyser became active again forcing some of the parks trails to be closed down. Lastly in the mid 1970’s Robert Smith, a geophysicist at the University of Utah found that the ground had risen 3 feet in 5 decades. The caldera continued to rise an inch a year until 1985 when it began falling an inch a year. However, in 1995 the caldera once again stated bulging towards the southwest.
     But is this any reason to worry? Geologists say no. The bulge on the bottom of the lake could have been there for thousands of years but not discovered until this new high resolution camera was developed. Changes in geysers are normal, and rangers often shut down trails as needed. As for the caldera floor, it has risen and fallen at least three times in the last 10,000 years.
Studies done by a research team at the University of Wisconsin analyzed crystals within hardened lava and concluded that the super volcano in Yellowstone is dying, but still in a potent cycle of volcanism. Some people believe the hot spot is moving under the Rocky Mountains and because it is a colder thicker part of the continent it will be capped, while others believe this won’t stop the force of this super volcano.
Smith and Robert Christiansen of the U.S. Geological Survey say they are not sure what this will do but they the volcano is not dead and there is no reason it won’t blow again.
Christiansen says he doubts the likelihood of another cataclysmic eruption soon, but because there have only been three catastrophic eruptions in the past there is not enough data to tell when the next one will occur. He suggests a blowout on the scale of Mount St. Helens is possible adding “we need to be prepared.”
Until then, the Yellowstone Volcano Observatory keeps a close eye on continuous geological changes happening in the park. It is unlikely that today’s modern instruments would not pick up on the threat of an eruption. Right now however, activity in the park is “business-as-usual.”

References: http://www.unmuseum.org/supervol.htm, http://news.nationalgeographic.com/news/2001/08/0828_wireyellowstone_2.html

The Day After Tomorrow” Could it Happen?

2006-05-15T07:28:00.000-04:00

Cheryl Kalman

The disaster film “The Day After Tomorrow” is a science fiction movie about an abrupt climate change cased by global warming that unleashes a “superstorm” on the unsuspecting world.
     The book the movie was based on “The Coming Global Storm” was co-written by Whitley Streiber and Art Bell. Their theory is that an abrupt climate shift would cause such instability that a “superstorm” must result. They believe powerful thunderstorms in the arctic would penetrate the stratosphere bringing upper atmospheric air as cold as 150°F to the surface. That would flash freeze anything caught outside. The thunderstorms would then merge together creating the “superstorm” they would suck energy from the oceans that were heated by global warming. The “superstorm” would create blizzard conditions with over a hundred feet of snow. In Canada temperatures would fall a 100°’s an hour. There would also be thunderstorms with large hail, and tornados.
     The scientific evidence they based this theory on was the discovery of wooly mammoths that had partially digested plant remains in their stomachs. Streiber and bell said "The sudden freezing that killed these animals required much more than a bad storm. It required a storm that was capable of delivering unprecedented levels of extreme cold to the surface and doing it so suddenly that the animals which were caught placidly grazing, did not even have time to look up [...] To all appearances they were simply frozen solid where they stood without enough warning to do more than raise their heads." That’s a pretty large assumption to make when ice core, sediment core, and tree ring studies show no evidence that a “superstorm” ever existed.
     But Bell and Streiber are not scientists. “Whitley Streiber is a UFO expert and author of the best-selling 1985 book Communion, a non-fiction account of his abduction by extra-terrestrials. Art Bell hosts a nationally syndicated all-night radio show, Coast to Coast AM, which specializes in UFOs and the supernatural.”
     The first part of the theory we can disprove is the flash freezing due to upper atmospheric air being sucked down to the surface. The air would be warmed on the decent to the surface according to the Ideal Gas Law, no matter how fast the air is moving. Next large storms that have calm eyes over land could never happen. Storms with calm eyes are hurricanes and can only occur over water they need the water vapor for energy. You would need 1200mph wind to create the 300 foot wave which hits Manhattan (that’s twice the speed of sound) and in the movie there is no wind. The last part we can analyze is not the authors fault, in many scenes the “superstorm” is shown rotating clockwise and in other scenes rotating counterclockwise. All storms in the northern hemisphere must rotate counterclockwise. Rotating clockwise would break one of the laws of physics on a rotating planet called the Coriolis Force. As a TV production major my guess is, a continuity error.
     But that doesn’t mean global warming isn’t a problem. If a certain temperature is reached an abrupt climate change could occur. But when scientists refer to “abrupt” they mean a change over decades rather than centuries. If an abrupt change did occur scientists are worried that the West Antarctic ice sheet would break up or the Atlantic thermohaline would shut down. The Atlantic thermohaline is like earth’s air conditioner The Gulf Stream carries warm water from the tropics to the North Atlantic where the water cools and sinks to the ocean floor where it is carried back south again. This ocean circulation pattern is caused by differences in water temperature and salinity in the ocean. The increase in ocean temperatures will increase the amount of freshwater dumping into the ocean. Some climate models show that higher ocean temperatures and reduced salinity could slow the thermohaline circulation while other climate models project a complete shutdown.
     Another effect of global warming will be increased flooding, increased droughts, more severe storms; which we have already seen with Katrina and Rita, also a loss of plant and animal species.
     In conclusion, “The Day After Tomorrow” is science FICTION and is not a true representative of what would happen if an abrupt change in the climate occurred. But the truth is global warming is happening and it is already too late to avoid some of the consequences.

References:
http://www.wunderground.com/education/thedayafter.asp

http://www.pewclimate.org/dayaftertomorrow.cfm

Intelligent Design

2006-05-15T06:50:00.000-04:00

Heather Skula

As geology students, we are taught about theories of evolution and natural selection. These topics are classified as Science, because we are able to prove these theories correct with many traces of evidence. Well, imagine if there were teachers trying to teach a "scientific theory" to students that are showed no evidence to it? Unfortunately, this is happening right now.

Intelligent Design is the idea that there is a creator behind the creation of earth and life. Advocators of Intelligent Design believe that certain living things (and certain parts of the universe) are too complex to have formed just by natural selection and/or evolution. Phillip E. Johnson is considered to be the "father of Intelligent Design." He has said that "the goal of intelligent design is to cast creationism as a scientific concept." Just with him saying that, I think that it is quite obvious that advocators of Intelligent Design see the "intelligent creator" as being God. Another advocated of Intelligent Design is William Dembski. He is known for creating the concept of "specified complexity." He believes that some things are too complex to be natural, and therefore there must have been an intelligent "designer" that created it. Unfortunately, advocators of Intelligent Design only look at origins of life that have not yet been figured out by Science. Science that lacks a natural explanation for evolution is then taken by advocators of Intelligent Design and labeled as being created by an intelligent planner.

Okay, now that the idea of Intelligent Designed is defined, I want to get into my (and many others) main concern about it: the fight to teach Intelligent Design in schools. If Intelligent Design is taught in classrooms, by law, it is going against the Establishment Clause of the First Amendment. The Establishment Clause states that no religion should be preferred over another by congress. If Intelligent Design is legally taught in a Science room, it is telling students that there was an "intelligent creator" that planned out the origin of life. This "intelligent creator" is also known as God. It has been stated by advocators of Intelligent Desing that the "designer" is seen as the Christian God, therefore excluding every other religion in the world. Although that is never stated to the public, it is widely believed among followers and supporters of Intelligent Design. Advocators of Intelligent Design try to stay away from discussions dealing with christian beliefs, creationism and the bible (when dealing with the public) because they don't want it to be seen as something religious. Many leading advocators are in fact Christians and do believe that the "intelligent creator" is the Christian God.

In his book, Intelligent Design: The Brigde Between Science and Theology, " William Dembski wrote, "Christ is indispensable to any scientific theory, even if its practitioners don't have a clue about him. The pragmatics of a scientific theory can, to be sure, be pursued without recourse to Christ. But the conceptual soundness of the theory can in the end only be located in Christ." If that isn't considered to be religious, then I don't know what is.

So, now we come to the impact on education systems-- actually teaching this as Science. In November 2005, the board of education in Kansas voted six-four in favor of teaching the flaws in evolutionary science. This meaning that at a high school level, Intelligent Design is allowed to be discussed as science material. My problem with this: many high school students have not yet grown enough to understand themselves. They are not old enough to figure out what it is that they want to believe when dealing with how the earth/life was created. I honestly do not have a problem with other people's beliefs, it's open-mindedness... but when students are being taught that Intelligent Design is Science, I think (as well as many others) that it is insane. Advocators of Intelligent Design do not care about the freedom for others when it comes to choosing what they want to believe in. Instead, they want all to be taught Intelligent Design, especially young adults who are easy to mold.

Major Tsunami Threat in the U.S.

2006-05-13T09:11:00.000-04:00

Cheryl Kalman

Ever since the South-East Asian tsunami happened a lot of countries have been asking “can it happen here?” Kevin Furlong a professor of geosciences at Penn State says “Unfortunately the answer is yes – big time.” Undersea landslides caused by small earthquakes off the coast of California can cause isolated tsunamis but, that is not the real threat to the U.S. The threat lies in an area known as the Cascadia Subduction Zone; it is a 600 mile wide fault off the Pacific coast that stretches from Northern California to central Vancouver Island.
Evidence suggests that 300 years ago the Cascadia Subduction Zone ruptured and caused a tsunami equal to the one that devastated South-East Asia. Researchers have found deposits of sea floor sediment in Oregon, Washington and British Colombia, at areas too far inland to be reached by normal tidal activity. When a tsunami occurs it picks up large amounts of sand and deposits it however far inland the water reaches. Another strong piece of evidence is tree ring dating shows that the northwest forests were killed by cataclysmic flooding around the same time. Native American legends still survive in many tribes that also depict this horrifying tsunami. However, the strongest piece of evidence came from the Japanese who have been recording tsunamis for 1,300 years. Japan got hit by a tsunami without warning on January 26, 1700. There was no earthquake felt at all there. Scientists recently determined that a 9.0 magnitude earthquake struck along the Cascadia Subduction Zone in 1700, creating a tsunami that hit the Pacific Northwest while also sending 16-foot-high waves slamming into Japan 10 to 20 hours later.
The geologic record has revealed that this type of rupture happens once every 300-500 years and that means we are due for another one. Experts predict you will only have 15-30 minutes to evacuate coastal towns because the plate boundary is only 100 kilometers off shore.
The 1964 tsunami that hit Alaska prompted the government to establish the federal tsunami monitoring system. This is run by the National Oceanic and Atmospheric Administration. Although the U.S. has set up advanced siren systems along the coasts that are more susceptible to tsunamis; with such a short evacuation time experts are not sure how much this will help, all they know for sure is when this Subduction zone ruptures again the devastation will be great.

Reference:

http://live.psu.edu/story/14499

Big Bugs of the Paleozoic

2006-05-03T06:08:00.000-04:00

Bill Marrs

Fossil evidence shows that during the Paleozoic era (245-570 million years ago), insects such as dragonflies, cockroaches and millipedes were a lot bigger than today’s insect relatives.  Jon Harrison, a professor of biology at Arizona State University, became interested as the reason why some insects were larger than today’s.  He believes the answer lies with what researcher’s found when analyzing the composition of ancient soils.  Researchers found that there may have been periods of time during the Paleozoic when the oxygen concentration in Earth’s atmosphere was considerably higher than ever before.  These findings suggest a concentration of 35% oxygen in the atmosphere that occurred for approximately 100 million years, and then dropped to 15% before reaching a current concentration of 21%.  The geologic record shows a rise and fall of oxygen levels that coincide with the evolution and extinction of large insects. Flight muscles of insect’s burn more oxygen than any other animal tissue. Harrison claims that if these insects existed, there must have been oxygen levels that supported these muscles.  Harrison plans future research to examine what he found in the lab under more natural conditions.
     The method of research Harrison used involved examining the study of the previous geologic findings of Robert Dudley from the University of Texas, at Austin, and Jeffery Graham of the Scripps Institute of Oceanography in La Jolla, California.  In their own research in controlled environments, Harrison and Scoot Kirkton (a graduate student at Arizona State University) tested aerobic performance of grasshoppers and dragonflies.  They tested different sized grasshoppers and dragonflies at varying oxygen levels to see how they performed.  They found that large grasshoppers and dragonflies were more active at high oxygen levels while activity diminished at low oxygen levels.  They also found that small grasshoppers are also more active and are not bothered by oxygen levels as low as 5%.
     I believe this research is relevant to modern atmospheric and climate research because it shows us that there has been a great change in our atmospheric composition since the Paleozoic.  This gives us insight into how our atmosphere was formed and how it may change in the future.
     I never knew that oxygen levels changed that drastically since the Paleozoic.  I thought oxygen levels gradually rose to a maximum level of 21% and that this level did not fluctuate from this value a great deal since the Paleozoic.  I also did not know that there is such a tight relationship between body size and metabolic rates in animals as small as insects.
     I think it is quite possible that increased oxygen levels during the Paleozoic could have paved the way for the evolution of super-sized insects during that time.  However, I also believe there must have been other factors involved as well.  I believe that many factors such as the amount of possible available food resources during that time and the likelihood that larger insects would have been easier prey for predators and were not discussed in the article.  Although the fossil record may not be able to give us this information, I believe that a rise in oxygen levels discussed in the article is a credible reason for seeing large insects in the fossil record as Harrison’s theory predicts.
The article can be found at:  http://researchmag.asu.edu/stories/bugs.html

Correlation of Dansgaard-Oeschger Events in Glacial Cores to Continental Strata of the Southwest United States: Evidence of Global Impact

2006-04-20T06:16:00.000-04:00

Sean Tvelia

During the last glacial maximum Greenland ice cores recorded variations of oxygen isotope ratios that have since revealed a series of rapid warming events followed by a gradual cooling. Researchers recognize twenty such events, known as Dansgaard- Oeschger events, occurring between 100kya to 14kya with a periodicity of roughly 1500 year. Little evidence of these warming events exists in continental strata which leads some to speculate whether or not these events were global events. Current research conducted on lake sediments in the southwest United States seems to indicate transgressive/regressive cycles also on the order of 1500 year cycles. This evidence, along with flora evidence, such as variation in pollen, seems to indicate that these rapid changes in climate as recorded in the Greenland ice core may have indeed been global events.

Most of our knowledge of Dansgaard- Oeschger events comes from three ice cores: The Greenland Ice Core Project (GRIP), The Greenland Ice Sheet Project 2 (GRISP2) and the West Antarctica Byrd Station (Roe & Steig, 2003). As can be seen in Figure1, these cores all show d18O variation occurring with a regularity of about 1500 years.

Since d18O ratios are directly related to temperature, the variation of d18O within ice cores represents the fluctuation of Earth’s climate (Ganopolski & Rahmstorf, 2001). In the three studied cores, d18O levels indicate a relatively fast warming trend, with mean temperature changes on the order of 10°C, over just a few decades (Roe & Steig, 2003). This rapid warming event, represented by the spike in d18O in figure 1, is followed by a gradual return to cooler temperatures. Twenty such variations have been recorded in the Greenland and Antarctic ice cores and are labeled 1-20 in figure 1.

With such great fluctuation in temperature over relatively short periods of time there have been many attempts to model processes that may trigger these events. Most of these models involve adjustments of the global thermohaline current due to variability in solar radiation, due to sub-Milankovitch cycles, and fresh water influx. This however suggests that Dansgaard-Oeschger were not simple polar anomalies and indeed have global implications.

Finding evidence of Dansgaard-Oeschger events within continental strata has been somewhat daunting.  Glacial advances during successive cooling phases would have no doubt removed all traces of previous glacial retreats during the rapid warming phase therefore leaving behind little to no trace of the event. Therefore, continental correlation of these events relies heavily on the impact on local deposition due to climatic variation caused by possible Dansgaard-Oeschger events; specifically lacustrine deposition which are intrinsically tied to local climate variation.

Local climatic variation during the last glacial maximum is most directly related to the development of high pressure cells over glaciated regions.  During the last glacial maximum high pressure cells that developed over the Laurentide Ice Sheet acted as a wall that forced the jet stream over progressively lower latitudes (Tchakerian & Lancaster, 2000). This, in turn, forced Pacific storm to track further south and led to increased precipitation in previously arid regions. This southward movement of the ice sheet also led to increased aeolian processes due to the sharp pressure gradient that existed between the cold glaciated regions and the warmer basin regions of the Southwest (Tchakerian & Lancaster, 2000).

Evidence of cyclical variation in deposition in response to Dansgaard-Oeschger events can be seen in the southwest United States and Northern Mexico. One such region, the Trans-Pecos Basin (figure 2) records fluctuating paleolake levels that seem to reflect Dansgaard-Oeschger events due to the geologic nature of the basin.

/Wilkins and Currey noted that “The Trans-Pecos closed basin is an internally drained and hydrographically closed region located between the Pecos River and the Rio Grande drainages in far west Texas and south central New Mexico” (Wilkins & Currey, 1996).  The basin encompasses an area of over 20,000km2 and ranges in elevation from 2835ft in the north to 1087ft in the south (Wilkins & Currey, 1996). In 1948 P.B. King proposed that beach ridges along the northwest margin of this basin were evidence of Pleistocene lake levels; this area is now dubbed Lake King (Wilkins & Currey, 1996).

Although current annual rainfall in the area (total- 280mm to 760mm) seldom reaches the floor of the basin, the Permian Bone Spring limestone provides significant groundwater to the region (Wilkins & Currey, 1996). According to Wilkins and Currey, Bjorklund determined the water table to be very near the surface of the basin which results in numerous visible depressions and sinks. (Wilkins & Currey, 1996)

Evidence of Lake King consists of “finely laminated centimeter scale couplets of olive green and gray” evaporate laminae which are composed of calcite, gypsum, and halite.  Hussain et al. (1988) identified the olive layer as being gypsum rich while the darker gray layer is micritic and richer in organics (Wilkins & Currey, 1996).

This varve-like pairing of layers seems to indicate seasonal deposition of the sediment. Wilkins and Currey suggest that this was created when seasonal runoff increased calcium levels and flushed organic material into the lake, creating the dark gray micritic layer. Then when runoff decreased total alkalinity also decreased. During these periods the lake became enriched in sulfate due to underlying groundwater influx and gypsum deposition occurred (Wilkins, Currey, 96).

Throughout these varved lake sediments are layers of blackened dolomite that have been termed “black mats” during a previous study by Friedman (Wilkins, Currey, 1996). These layers are enriched in 18O and therefore suggest being formed during periods of increased evaporation or lowered precipitation (Wilkins, Currey, 1996).  Friedman’s theory suggests that during these periods, dense brines forming along the margin of the lake would have sunk to the center and replaced the previously formed calcite with dolomite (Wilkins, Currey, 96). This model then suggests that the dolomite production would also coincide with shallow lake levels and therefore regressive periods.

When precipitation returned to the area, freshwater influx via runoff would have interrupt the normal thermohaline circulation and resulted in anoxic conditions at the base of the lake(Wilkins & Currey, 1996). Sulfides, produced through metabolic processes of anaerobic bacteria, then reduced iron oxides present in the lake and blackened the dolomite(Wilkins & Currey, 1996).

In this model the initial production of dolomite indicates dry, arid climates and regressive phases of the lake. Black mats, on the other hand, reflect transgressive phases of Lake King and must also reflect moist or humid climates. Along with

providing stratigraphic evidence of these climate shifts, black mats of the Trans-Pecos basin also contain enough organic carbon that may be radiometrically dated.

Radiocarbon dates of black mats reveal a similar pattern to Dansgaard-Oeschger events in Greenland ice cores. Figure 3 shows the correlation of black mat production ages with lake surface elevation as identified by shoreline. The lowstand, which is illustrated by dolomite production, was arbitrarily determined by the lowest visible shoreline (Wilkins & Currey, 1996).

Further evidence of the global impact of Dansgaard-Oeschger events can be seen along the Owens River system of the southwest United States.

Pictured in Figure 4, the Owens River system is fed by discharge from the Sierra Nevada Mountains. This system is made up of a series of closed basins, each of which receives overflow waters from the previous basin starting with Owens Lake.  This creates a chain of pluvial lakes that, at times, extended into Death Valley (Tchakerian & Lancaster, 2000).

During the last glacial maximum, this system would have been fed by alpine glaciers in the Sierra Nevada Mountains and may have also received additional waters from the overflow of Lake Mono just north of the Owen River headwaters (Tchakerian & Lancaster, 2000).

Tchakerian & Lancaster further note that stratigraphic data indicate that Searles Lake levels went through significant oscillation between 100-25ka, with the greatest fluctuations occurring between 34 and 26ka. These fluctuations are marked by evaporate layers which would indicate the onset of an arid climate (Tchakerian & Lancaster, 2000).  During this period Searles Lake appears to have had six major transgressive/regressive cylces (Figure 5) that can be correlated with Dansgaard-Oeschger event in the Greenland ice cores.

According to Tchakerian & Lancaster, similar oscillations have also been detected at Mono Lake, where each low lake level lasted between 1000 and 2000 years (Tchakerian & Lancaster, 2000). The cyclical nature and timing of these events do seem to indicate a correlation between arid/humid cycles in the southwest resulting from Dansgaard-Oeschger events recorded in the Greenland cores.

Based on models produced by Hostetler and Clark, control of glacial advance and retreat in most of the western United States during the last glacial maximum was dominated by changes in global temperature (Hostetler and Clark, 1997). In the Sierra Nevada Mountains, however, this same model shows that the advance and retreat of alpine glaciers was dominated by precipitation. This model fits well with Tchakerian & Lancaster’s model that suggests that displacement of the jet stream by the advancing ice sheet forced Pacific storm tracks further south. This, in turn, led to increased precipitation over the Sierra Nevadas, which in turn led to alpine glacial advance that fed the Owens River system.

Fluctuations of lake levels recorded in the stratigraphic record of these two localities along with the timing of the events imply correlation between events recorded in the Greenland and Antarctic ice cores. These correlations suggest that temperature fluctuation recorded by d18O in Greenland ice cores was not limited to the Polar Regions. Furthermore climatic modeling of the last glacial maximum also correlates with processes leading to transgressive/ regressive cycles in the study region.

References:

Ganopolski, A. and Rahmstorf, S., 2001: Rapid changes of glacial climate simulated in a coupled climate model. Nature, 409, 153-158

Hostetler, S. and Clark, P, 1997, Climatic Controls of Western U.S. Glaciers at the Last Glacial Maximum, Quaternary Science Review, v16, p. 505-511

Roe, G.H., Steig, E.J., 2004, Characterization of Millennial-Scale Climate Variability, Journal Climate, v17 no. 10, p.1929-1944

Tchakerian, V.P. and Lancaster, N., 2002, Late Quaternary Arid/Humid Cycles in the Mojave Desert and Western Great Basin of North America, Quaternary Science Reviews, v.21, p. 799-810

Wilkins, D.E. and Currey, D.R.,1997, Timing and Extent of Late Quaternary Paleolakes in the Trans-Pecos Closed Basin, West Texas and South Central New Mexico, Quaternary Research, v. 47 p. 306-315

The Arctic Circulation Current: Evidence of Man's Impact on the Climate

2006-04-20T05:58:00.000-04:00

Bill Mars

While doing research for Global Climate class I came across an interesting article. This article, “Human-Induced Change in the Antarctic Circumpolar Current, “ by John C. Fyfe and Oleg A. Saenko of the Centre for Climate Modeling and Analysis, Meteorological Service of Canada, University of Victoria states that the Antarctic circumpolar current (ACC) is expected to continue to shift. The authors claim that two theories are responsible for this shift, balancing surface Ekman drift and ocean eddy mixing.

Previous research showed that the increases in ocean temperatures found in the ACC are comparable to Antarctic atmospheric increases in temperature as sited in the article. Also as sited in the article, changes in surface winds can influence movement of the ACC and it is claimed that this change has a human cause. A shift in the ACC correlates with the industrial revolution and increased greenhouse gasses being emitted in the atmosphere since the 1950’s and this shift can possibly affect global climate patterns in the future.
The method of research involved the study of previous data on the ACC as well as testing mathematical models produced by the authors. Hydrographic, atmospheric data, and data from the National Centers for Environmental Prediction–National Center for Atmospheric Research, European Centre for Medium-Range Weather Forecasts, Canadian Centre for Climate Modeling and Analysis, Intergovernmental Panel on Climate Change were used in coordination with global climate models to conclude that the shift in ACC is at least partially human induced. The authors gathered information previously conducted and used that to support results from models used involving mathematical theory.
I believe this research just adds to the mountain of evidence that our effect on the planet as humans is profound. The ACC, the author describes, is quite large and any change or shift in this current is likely to affect global climate. We all need to be aware of our huge influence on global climate. The research also points out that much of this change has occurred within the last 50 or so years. Research like this show the potential impact of this shift on continental climates. However, it is important to share this information with the general public in such a way that is understandable and easily digested so that human activities can change for the better.
I never knew that the ACC was so large and influential on global climate. Also I never realized how much humans can affect remote areas of the globe in such a short period of time. Although I did not understand some of the mathematical models, it seems that coordination of previously published data can be a powerful tool in discovering new trends in our atmosphere as well as with our climate. Also, I learned that new mathematical models and mathematical theory can be a powerful way to express trends in nature.Humans have impacted our planet to a great extent. Although I am a bit biased with that thought, I believe this research proves that we can and have had influence on global climate, particularly the Antarctic Circumpolar Current.

Research makes many credible points about this influence and backs them up with real data. The authors collected a considerable amount of data that was published previously as well as conducted their own models. Previous knowledge in science builds on new thoughts and ideas and I think this article make a good example of this important process in science. However, the article did not mention any of previous geologic findings. Earth goes through cycles that are much longer that we as humans can understand. I am pretty sure that people have looked into the geological record, for example, the continental red bed depositions, for evidence of ozone’s rise and fall. Do many geologists think the recent (geologically) ozone depletion is just a part of Earth’s normal cycle in addition to human effects?
The article can be found at http://www.cccma.bc.ec.gc.ca/papers/jfyfe/PDF/FyfeSaenko2005a.pdf

BBC NEWS | Science/Nature | Stark warning over climate change

2006-02-04T17:52:00.000-05:00

BBC NEWS | Science/Nature | Stark warning over climate change

Rising concentrations of greenhouse gases may have more serious impacts than previously believed, a major scientific report has said.

Sedimentation at Democrat Point- John Bucaro

2005-12-22T06:05:00.000-05:00

To the south, Long Island is bordered by Fire Island. Fire Island is a series of Barrier beaches that provide the south shore of Long Island with some protection from hurricanes and other storms. The formation of these barrier beaches can be approached in two different theories.
“The most widely held hypothesis is that of ‘shoreface retreat’. This view states that as sea level rises, the barriers migrate continuously landward, mainly through the combined effects of shoreface erosion and washover on the landward sides of the barriers. During the migration, the breaker zone traverses the entire area submerged... The contrasting view, that of in place ‘drowning’, states that as sea level rises, the barrier may remain in place, while the lagoon on it’s landward side deepens and widens.

Eventually, the breaker zone reaches the level of the top of the barrier, the sea drowns the barrier, and the breaker zone oversteps landward to form a new barrier shoreline along the landward edge of the former lagoon” (Rampino and Sanders, 1981).

The barrier beaches of Long Island are often undergoing analysis to understand how much they are eroding and at what rate. It is a difficult task because often times the sand may not be gone from the barrier simply moved to another are of the island. Currents and long shore transport move sediment along the beach and in and out of inlets.

“Circulation patterns are specific to each inlet, but certain properties are common to many inlets. Common properties include ebb or flood dominance, preferred channel on ebb and flood tide, eddy formation and migration, and jetty control on flow patterns” (Militello and Hughes, 2000). At Democrat
Point, near the Fire Island inlet, a large jetty was constructed to prevent sediment being transported into the inlet and filling in the inlet. Since the predominant sediment transport direction is from east to west the east side of the jetty has filled in with sediment.

There is also a jetty across the inlet from Democrat Point. The two jetties are not parallel and can thus be classified as offset jetties. In this situation the current is affected and becomes strongest on the sides with the shorter jetty and water enters the inlet at an angle to the inlet center line Militello and Hughes, 2000). Since the tidal currents combined with longshore transport effect sediment distribution one would think that the jetties effect on the currents would result in unexpected sedimentation patterns.

This study attempts to analyze the sedimentation patterns around the jetty at Democrat Point through grain size analysis. As currents slow down the larger, heavier grains will fall out of solution first. Smaller, lighter grains are still able to be transported by a slow moving current. Since the jetty effects the currents around the inlet a grain size analysis should allow one to determine the jetties effect on sedimentation processes.
Results

Phi size is a useful measurement when doing grain size analysis. The larger phi sizes correlate with smaller grains; therefore a phi size measurement of
4 is a smaller grain than a phi size measurement of 0. Sorting by phi size also allows one to separate the grains out and measure the percentage of the sample within each phi size. By dividing the weight of the sediment in a particular phi size by the total weight of the sediment in the sample one can determine the percentage of the sample in that grain size. Using the percent composition of each phi size is useful because it allows us to see what size most of the grains are. If a higher percentage of the grains are large than we know we’re looking at a coarse sediment where as if the majority of the grains are smaller than we have a finer sediment. Whether the sediment is coarse or fine allows one to determine the type of depositional environment.

In conclusion, we can see that all of the samples are dominated by grains in the larger phi sizes. However, it is worth noting that in the sample furthest east we saw dominance in the top two phi sizes and very little grains in the smaller phi sizes. As one moves further west the grains are more evenly distributed throughout the phi sizes although still the majority are in the larger phi sizes. (See attached spread sheet and graph).
There is also a pattern that is noticeable in the smaller phi sizes. As one moves from location 1 to location 4 (east to west) there is an increase in the percent of grains contained in the smaller phi size category (See attached spread sheet and graph). One would think that the locations closer to the inlet would have a small percentage of grains in the small phi size category because of the increased current. However, this did not occur in this study. One possible reason for this could be that the locations were still too far from the inlet to be greatly effected by the currents.
One might think that the large jetty built at Democrat Point would have an effect on the distribution of sediment and grain sizes. In this study there is very little evidence that the jetty had much effect at all on the distribution of grain sizes. There is an overall general pattern that as one moves from location 1 to location 4, east to west and closer to the inlet that the grain sizes become more evenly distributed throughout the phi sizes.
The jetty does not seem to have any significant effect on this general pattern. The jetty was originally built to keep sediment out of the inlet and prevent the filling in of the inlet. It seems to be succeeding in some degree in this area. The beach on the east side of the jetty (away from the inlet) is significantly larger than the beach on the west side of the jetty. On the east side of the jetty the beach extends approximately 10-15 meters further seaward.

References
Militello, A. and Hughes, S.A. (2000). “Circulation Patterns at Tidal Inlets
with Jetties,” ERDC/CHL
CETN-IV-29, U.S. Army Engineer Research and Development Center. Vicksburg,
MS.
Rampino, R. and Sanders, JE. (1981). Evolution of the Barrier Islands of
Southern Long Island, New York.
Sedimentology 28. pp 37-47.

The Jurassic As Observed in the Deerfield Basin

2005-12-21T20:13:00.000-05:00

By John Bucaro

When the super continent Pangea broke apart a series of rift basins were created along what is now the east coast of the United States and down through Central America. The focus of this work is on the northeastern U.S. along the rift zone and more specifically the Newark super group. The Newark super group formed in the late triassic-early jurassic as a result of sedimentation in the rift basins created by the rifting of Pangea. The outcrop studied in this paper is found in the Deerfield basin in Turner Falls, Massachusetts and is of jurassic age (Rasbury 2005).
Certain cycles can be found in the exposed strata of the rift basins. These strata can be used as clues to determine the history of the area, its climate and tectonic activity. All of these findings give one an insight to the depositional processes of the late triassic-early jurassic time period. The sedimentation appears to be lacustrine in nature and the cycles are of a dry-wet-dry nature (Olsen 1997). These cycles are referred to as Van Houten cycles and they suggest the rising and falling of sea level, seasonality, tectonic activity, uplift and various other processes effecting water levels (Olsen 1997). Observation of the Van Houten cycles and further studies of the strata in general can give evidence to transgressive or regressive shorelines and allow for an interesting look at climate changes, plate tectonics and plate positioning during the late triassic-early jurassic.
“The basins show strong vertical changes in overall facies reflecting an interplay of large-scale tectonic and climatic changes with time.” The vertical progression of a cycle consists of a lower area of fluvial deposits and progresses upward to an area of deeper water facies and then transitions back to shallow water fluvial facies again. The Van Houten cycles suggest a cyclical change in climate. The most compelling theory for the climatic change is that of the milankovich cycles, especially the eccentricity of the Earths orbit (Olsen 1997).
In the Newark Basin the Van Houten cycles suggest the deepening and shallowing of lakes. The laminate organic rich layers are representative of a deep stratified lake environment. To have chemical stratification of the lake the depth must be significant approximately 80+ meters. The other end of the cycle is the shallowing of the lake to a playa lake environment(Olsen 1986). In the playa lake thin red, iron rich mudstone and sandstone should be prevalent. There may be some fluvial structures as well indicative of paleocurrents and other fluvial processes. Mudcracks found in any of the strata are indicative of a periodic drying up of the lake once again showing evidence for climatic changes.

I believe this area was lacustrine in nature. It was probably predominantly a playa lake for most of the time as red mudstones and sandstones are most prevalent. The lake must have been shallow enough to allow for oxidation of the iron minerals present. Also the presence of fluvial features in some of the layers suggests that currents were able to have some effect on the bottom sediment of the lake. We also see a few periods where mudcracks are present. The climate must have at one point been arid enough to dry up the lake, also the lake must have been shallow enough to allow for drying up which leads me to believe it was no more than 5-10 meters deep during the playa stage(Olsen 1997). The presence of burrows in some of the layers also leads one to believe that it wasn’t very deep and fairly low energy because animals were able to live in the environment or plants were able to take root in the environment and the burrows remained after the organisms were gone.
The grey material and especially the black fish beds suggest a period in which there must have been a deep stratified lake. Stratification is significant as it suggests the lake was probably at least 80 meters deep (Olsen 1997). Without the stratification the organic material in the fish beds probably would not have been preserved. Oxidation of iron material is less in the deeper stratified lake and we see less of the red coloration at this point in the section.
The overall Van Houten cycle seen in the section is evidence of the changing of climate and environment through the milankovich cycles, plate movement, and tectonics. The fault found in the section suggests active plate tectonics which cause some local low grade metamorphism. Also as the plate drifted through different latitudes climate changes and environment changes will occur. The milankovich cycles obviously change the climate as they are the primary reason for the Earth’s transition in and out of ice ages (Olsen 1997). The overall Van Houten cycle reinforces these theories but we also see smaller changes within the section.
The transitions from mudstone to sandstone and differences in grain sizes suggest the area went through changes in flow regime. Possibilities include river, glacial melts, turbidites and various others however i think the most important information we can take from this is the idea of seasonality. There must have been some seasonality in the area because of the differing flow regimes we see and there occurrence in cycles. Even if one argues that it was due to river influx the differing flow regimes suggest that the river had different flow rates at different times. I think the sandstones and higher flow regime areas are representative of the spring and summer snow melt and run off from the mountains where as the mudstones and lower flow regime structures represent fall and winter periods of less water influx.

Reference:
Olsen, Paul E. Palisades, NY Science 234, (1986). A 40-Million-Year Lake Record of Early
Mesozoic Orbital Climatic Forcing. Pp 842-848.
Olsen, Paul E. Columbia University, Palisades, NY Science 25 (1997) STRATIGRAPHIC RECORD
OF THE EARLY MESOZOIC BREAKUP OF PANGEA IN THE LAURASIA-GONDWANA
RIFT SYSTEM. Pp 337-401.
Rasbury, Troy. Geo 403/543 FIELD TRIP TO JURASSIC OF DEERFIELD BASIN. Class handout.
2005.

Newsday.com: Ancient Indian burial site found in Riverhead park

2005-12-21T20:02:00.000-05:00

Posted by Liz
To read the original article click here.
I had to comment on this article because it was extremely interesting to me for more than one reason. For one thing, I have lived on Long Island my whole life and was always interested in Indians and artifacts. Also I live down the street from this park and I have always camped there growing up. It so weird that these remains were found because before this happened I was at the park about a week early right around were the remains were found.

A park in Riverhead “Indian Island Park” is a park open to the public for camping hiking golfing or any leisure activity. Recently bones, a pipe piece and bowl were found. The heavy rains we had in October must have brought the remains to the surface. The bones are believed to be from Indians, dating as far back as 800 BC to 800 AD. The bones were obviously burned, there was a piece of a jaw bone and skull, said to be from two or three different Indians. The pipe was still nearly perfect and said to have geometric detail on it. People said that it was obvious that these people were burned or cremated, which leads us to believe that this was a burial place. But why were they burned? Maybe they were cremated or maybe it was some sort of belief. Officials are not sure what to do with the remains yet. They feel that they should put them back and bury them because of the cultural beliefs. Right now they are being studied so they can be dated and find out exactly who they came from. If it was my decision I would probably bury them back up because it was obvious to be a burial ground from years ago. It’s so interesting to me. there are probably so many more bones and artifacts in that same spot. I wonder if the officials will go ahead and dig up more out of curiosity or let it go in peace. Right now police are watching this place very carefully, they don’t want any intruders.

Where did the Moon come from? Part 2 - The Big Whack by Joe Leddy

2005-12-15T21:20:00.000-05:00

Where did the Moon come from? (Part 2 " The Big Whack")

In my last post we looked at the Origins of the Moon and the "Big Three', theories that tried to answer the question of the Moons beginnings. All three had at least some scientific basis behind them, although they all turned out to fall short in one manner or another. So where does that leave the discussion? If the "Big Three" doesn't answer the question, what does?

Enter the currently accepted theory,"The Big Whack". In the mid 1970s this new theory started to come together. William Hartman (from the Planetary Science Institute in Tucson, Arizona) and Don Davis (a colleague from the PSI) determined that a roaming planetoid of significant enough size could theoretically knock enough of the mantle off of the Earth if it struck early enough after the formation of the planet.

Meanwhile at Harvard University, Alistair Cameron and William Ward determined independently of Hartman and Davis's work that a planetoid of at least the size of Mars could have provided the needed force to supply enough raw materials for the Moon.

Putting these two pieces of work together, "The Big Whack" Theory was born. It was not without its detractors, scientists tend to frown on outlandish answers to problems. So the theory sat without much work being put into it until 1984. In Kona, Hawaii a conference was held to discuss the origins of the moon, and research started to move forward on the Giant Impact Theory as it was know known. (Apparently Astronomers have a rough life with conferences in Hawaii, as apposed to digging in the middle of Montana like a Geologist)

Robin Canup, an astrophysicist from the Southwest Research Institute, modeled what such an impact would look like. Her calculations arrived at the conclusion that the impacting object would have to have been two to three times the size of Mars. She arrived at this conclusion based on her assumptions that only 20 to 50% of the material ejected from an impact would make it to form the Moon.

The Moon is less dense than the Earth, a moon forming from a cloud of debris from the impactor and the Earth' mantle would explain this. The Big Whack also explains the Moons tiny core; models show that the Earth would have absorbed any core within the impactor. And the Big Whack explains while the Earth rotates about an axis on a 23.5-degree tilt.

So far so good, however there are still holes in the Big Whack that need to be worked out. For instance, if the Moon is made up from a combination of an impactor and the Earth, why is there such an oxygen-isotope similarity between the two? Wouldnt you expect more of a difference? A second problem is the resulting spin of the Earth that would have resulted. If such a large object hit at an angle resulting in all of this debris, the planet would have a significant increase in its rotational speeds. How do we account for the lack of this spin? A second impact slowing the Earth down seems incredibly unlikely.

While there are still questions to be answered, the Big Whack is still the favored theory of lunar development.

For more information on the Moon and its origins
please see the following websites:

www.nasa.gov

www.pbs.org/wgbn/nova (origins by Peter Tyson)

Origin of the Moon by William Hartman published in
1984

www.space.com (Torn Away: The Moons Violent Birth
September 1 2000)

Where did the Moon come from (part 1 - The Big Three) by Joe Leddy

2005-12-15T20:23:00.000-05:00

Where did the Moon come from? (part 1 The Big Three)

Since the beginning of civilization man has been fascinated by the Moon. It has been worshiped,
feared, and studied. For centuries we have theorized how the Moon came to be.

The first modern scientific studies we conducted by Galileo in 1610, when he discovered that the light and dark spots were plains and mountains. Galileo was on the right path in his discoveries of how the Earth/Sun system worked, until the Church tried him for heresy and all published thoughts along these lines (at least within the influence of the Church) stopped.

Charles Darwins son George put the first theory of the origins of the Moon to gain some measure of acceptance forth. George Darwin theorized the Earth spun the Moon into existence. According to Darwin, the Earth in its infancy spun so rapidly that a chuck was pulled of an elongated Earth. Darwin initially put forth his theory in 1878. Four years later geologist Osmond Fisher added to the theory by stating the scar left behind from this fission was in the
Pacific Ocean. The Fission Theory was widely accepted well into the 20th century.

In 1909, some competition enters the Moon origins discussion. Thomas Jefferson Jackson See, an astronomer with quite possibly the most American name of all time, advocated the Capture Theory. According to See, the Moon was really a wandering planet that was captured by the Earths gravity.

There was still another theory that entered the fray. Edouard Roche, an astronomer advocated a co-accretion theory that the Earth and the Moon formed simultaneously from the same material that all of the planets formed from. This would come to be known as the Co-accretion Theory.

These theories were dubbed the Big Three, and were a source of much debate. Selenology, the study of the moons origins, really gained some footing after the Apollo missions (and corresponding Russian missions) brought over 800 pounds of lunar rock to study.

Studies of these rocks showed some remarkable similarities between the Earth and the Moon. Studies of the isotopes present in the rocks showed both bodies to be roughly 4.5 billion years old, and the quantity of stable oxygen isotopes showed a similarity in the distance both bodies formed from the Sun. The Earth and Moon were shown to be a system. This still does not tell us which of the Big Three was correct, if any.

The Fission Theory falls apart under study. It might explain the lack of a core in the Moon and the Moons similarity to the Earths Mantle, however it stops there. The physics behind the Fission Theory does not work. The speed at which the Earth would have had to been spinning is off the charts. Add that to the fact that the Pacific Basin is 70 million years old, not 4.5 billion and the theory is dead.

The Capture Theory also fails under a combined geological and physics based study. Geologically the chances that a planet developed elsewhere in the galaxy/solar system would have the same properties as the mantle, but no core, does not work. In addition the chances of an object the size of the Moon being captured by the Earth, at just the right angle and speed, are so small they are statistically impossible.

The Co-accretion Theory does not explain the lack of a core in the Moon. In addition, the chances that the Earth develops with all of the iron while the Moon has none make this theory very improbable.

If the Big Three are out, what's left? In part two of this post I'll look at a new theory that is leading the way"The Big Whack'.

Major Events in the 4 Sciences by Joe Leddy

2005-12-14T22:15:00.000-05:00

Events that change a scientific field

What are the major branches of scientific study today? For the purposes of this discussion I will break science as a whole into 4 major branches: Biology, Chemistry, Physics, and the Earth Sciences. People can and probably will argue that these classifications are too general, especially Earth Sciences. When you look at it from the perspective of unifying theories, discoveries, and events that bring the branch together, it starts to make sense.

Before we look at the theory/discovery that unifies the Earth Sciences, lets take a look at the other sciences to establish what these events look like.

In the field of Biology, Darwins Theory of Evolution changed the face of biological studies and gives direction to why things happen the way that they do. With evolution a biologist can uncover what mechanisms the species developed that make it suited for its environment. This line of questioning leads to how the species adapted, and ultimately the genetics behind the adaptation.

Chemistry started to take off as a science with the discovery of the atom. Prior to this discovery
chemists were nothing more than alchemists trying to turn lead into gold. With the atom, chemists eventually uncovered the structure behind the atom (protons, neutrons, and electrons) and how this structure allows all elements to interact.

Sir Isaac Newton made the major contribution to physics with his Laws of Motion. It is from these laws that modern physics (a.k.a. Newtonian Physics) came to be. By far this is the most important event in physics.

Now we come to the branch that seems to be the catch all for all other types of science. The Earth Sciences are made up of four distinct sciences in and of themselves. These sciences are geology, astronomy, oceanography, and atmospheric science.

Some might ask why these four are grouped together, after all isn't atmospheric sciences really a combination of physics and chemistry? And couldn't you argue that Oceanography has a large biological component to it? Well the short answer is yes, you can make those arguments, and however if you look at the theory that brings these sciences together you might change your mind.

Plate Tectonics is that theory; it unifies the four into the umbrella of the Earth Sciences. As you know, the theory of Plate Tectonics is concerned with the movement of lithospheric plates along the asthenosphere. These movements occur along divergent, convergent, and transform plate boundaries.

The real question is how Plate Tectonics ties geology, oceanography, astronomy, and atmospheric sciences together. It is a very clear connection for some and not so clear for others. Lets look at the clear ones first.

Geology is the obvious Earth Science; by definition is the study of the Earth. Plate tectonics explains a large portion of geology, from the development and recycling of older rock all the way to mountain building and earthquakes. Similar to Newton, plate tectonics offers a cornerstone in which geology can be built and grow.

Oceanography is another obvious Earth Science; a large part of it is similar to geology just
underwater. Plate tectonics explains the development of the world ocean and how it changes over time. Which oceans are growing and which are shrinking as well where new oceans may develop. In addition, plate tectonics gives rise to hydrothermal vents and the chemosynthetic organisms that have developed around them.

Atmospheric Science is tied into the Earth Sciences and plate tectonics in a round about way. The weather is a very complex system that is affected by a great many factors, however at its core it deals with the movement of air masses and the amount of moisture within that air mass.

Not seeing a connection between the movement of air and plate tectonics? Lets look at how air moves, parcels of air will either move above or below another parcel or rise and sink based on the air temperature. Air temperature is based on a number of factors, primarily the exchange of the heat from the land/water mass it was developed above. Plate tectonics affects the development of oceans and mountains, oceans and mountains greatly affect how these masses move and their moisture content. So, plate tectonics plays an indirect roll in an areas weather patterns on a geologic scale rather than a small time frame. Finally we come to Astronomy. This connection is not a simple as the others. Plate tectonics has nothing to due with Astronomy on a macro scale; rather it deals with a specific division within Astronomy. The study of planets and the search for live within the universe. Understanding how the Earth behaves gives astronomers a base on which to work with. Whether it is explaining quakes on another planet or looking for life, understanding plate tectonics and how it affects the Earth is a big help in their studies.

For more information on the Earth Sciences please
visit the following web sites:

www.nasa.gov
www.noaa.org
www.weather.com

Or look into classes at Suffolk dealing with these
subjects.

Ice Ages by Joe Leddy

2005-12-14T22:13:00.000-05:00

Ice Ages

Hollywood has developed an image of an Ice Age that is catastrophic and in the case of the movie "The Day After Tomorrow" sudden. There are many questions to be studied in order to understand what an Ice Age is. What exactly is an Ice Age? How are they caused? Are there Ice Age Cycles? And can global warming cause an Ice Age?

You can define an Ice Age as a period of a long-term downturn in the temperature of the Earths Climate, resulting in the expansion/growth of continental ice sheets/polar ice sheets, and the growth of mountain glaciers (taken from Wikipedia.com) this is also known as glaciation. It should be noted that you could still be in an Ice Age if the Glaciers are retreating; you are just in the process of coming out of the Ice Age. The term Glacial Periods refers to the colder period of the Ice Age and Interglacial refers to the warmer periods. (We are technically in an interglacial period following a retreat of ice roughly
10,000 years ago)

There are three generally accepted factors that cause
Ice Ages:

Atmospheric Composition - Carbon Dioxide and Methane
being the chief gases of concern (Decreases in
concentrations within the atmosphere)
Variations in the Earths orbit around the Sun (This
is known as the Milankovitch Theory - The Earth
wobbles as it orbits the Sun and it takes
approximately 41,000 years to complete one wobble.
The wobble is roughly 22 degrees. This tilt of the
Earth is the cause of our seasons. If the tilt
varies, say to 25 degrees, we could in theory have
dramatic shifts in our climate)
The Arrangement of the continents places a part as
well. If there are landmasses near the poles there is
a place for the ice to build.

Ice Ages do appear to come and go in a cycle. They generally occur at 100,000-year frequencies however they have been known to occur every 40,000 years. Geologists know the time line by the scrapes the ice leaves behind in the rock. This pattern has held for the last few million years. Within this time there has been 4 major Ice Ages.

The earliest is theorized to have taken place between 2.7 and 2.3 billion years ago, this would have placed it in the early Proterozoic Age. Next comes the Snowball Earth Ice Age, this took place 800 to 600 million years ago. It is referred to as Snowball Earth because permanent sea ice extended to or quite close to the equator. This Ice Age would have taken place in the Cryogenian period.

Roughly 460 to 430 million years ago, during the Late Ordovician Period, another one occurred. And finally there were quite extensive polar ice caps 350 to 260 million years ago during the Carboniferous and Early Permian Periods.

The last Ice Age began 40 million years ago and intensified during the Pleistocene with ice sheets spreading in the Northern Hemisphere. The last glacial period of this Ice Age ended roughly 10,000 years ago.

As you can see, if Ice Ages occur every 40,000 to 100,000 years, it is the mini ice age that is far more common than the major Day After Tomorrow types we see in the movies.

It is not global warming that causes the Ice Ages, rather the removal of Carbon Dioxide from the atmosphere. Global warming can indirectly affect this however. In theory, if the greenhouse effect melts the Ice caps the ocean currents could be drastically affected. If the currents are changed the blooming of plankton (photosynthetic organisms) can also be affected. If the bloom is too large, the process of photosynthesis (the conversion of Carbon Dioxide into Oxygen) canremove massive levels of CO2 from the atmosphere. It is that removal that has scientists concerned about another Ice Age. (Please keep in mind this is an over simplified explanation of a very complex process)

For more information please see the following:

Discover Magazine September 2002 - A New Ice Age:
The Day After Tomorrow
www.discover.com

www.ncdc.noaa.gov/paleo/glaciation.html

www.wikipedia.com
Or speak with or review Professor Mandias Website

The Dinosaur Extinction by Joe Leddy

2005-10-26T19:42:00.000-04:00

65 million years ago the most famous mass extinction occurred.  It was at this time that all of the dinosaurs died. What most people do not know is that along with the extinction of the dinosaurs 70% of all species on Earth became extinct at that time?  Therefore any theory that explains the demise of the dinosaurs must be comprehensive enough to include the extinction of the other species as well.

There are two serious theories that have gained acceptance within the scientific community to explain the disappearance of the dinosaurs, the meteor theory and the volcanism theory.  Both of these theories point to the same evidence of the extinction, however, they differ on the root cause.

Analysis of the rocks in and around the end of the Cretaceous Period was conducted by a team of scientists from the University of California (Luis and Walter Alvarez) in Gubbio, Italy.

What the Alvarez’ s discovered was a thin layer of clay that contained a large quantity of the element Iridium in the rock samples.  Iridium is an extremely rare element in the Earth’s crust, typically only about 0.001 parts per million.  In rock analyzed by the Alverez’s the quantity of Iridium was 30X that amount, this level of Iridium is typically only found in meteorites.  After the initial discovery in Italy, scientists discovered Iridium in many samples from the same layer(now know as the K/T boundary, all over the Earth.  The key to the dinosaur’s extinction is in origin of the Iridium.

It is possible that volcanism could explain both the clay layer and the abundance of iridium. This theory begins with the formation of the Earth.  When the Earth was still molten it was possible, and likely probable, that meteors containing Iridium continued to crash into the planet.  As the planet cooled the Iridium contained in the meteors was buried deep within the mantle of the Earth.

A series of violent volcanic eruptions that would bring molten material from the mantle to the surface would have then thrust the Iridium out into the atmosphere (in addition to the tons and tons of additional particles).  Once in the atmosphere these materials formed a barrier, that blocked sunlight from reaching the Earth, which led to a global cooling period and eventually an Ice Age.  This shift in the global climate is what is ultimately believed to have caused the mass extinction.

The more widely accepted theory states that a large meteor (about the size of Mt. Everest) containing large amounts of Iridium crashed into the Earth about 65mya. An enormous amount of energy was released during the collision, which sent tons of debris into the atmosphere.  Just as in the Volcanism Theory, this led to the serious climate changes that followed.  Why should this theory be more widely accepted?

Volcanic eruptions are very common within the history of the Earth, and out-gassing (the process by which volcanoes released gas and contributed to the formation of the atmosphere) has been established to operate on a global scale.

Why would the Iridium show up in these quantities in a “single” geological event?  If it is present in the Earth would we see a more uniform concentration of it, or see less of it on a more frequent basis.

The Meteor Theory explains the presence of the Iridium on a one off basis.  It has been calculated that a 10km meteor, which is not that big on a cosmic scale, would contain enough Iridium to account for the levels found.

Until 1990, many geologists had asked the question “Where is the crater?”  In 1990 Alan Hildebrand was reviewing some data from some scientists looking for oil in the Yucatan region of Mexico.  Mr. Hildebrand uncovered a ring like structure near the small town of Chicxulub; this ring is roughly 65Million years old and 180km in diameter.  This diameter is consistent with the impact of a 10km meteor.

So currently the evidence seems to suggest the Meteor Theory has some credence.

For more facts and theories see the following links and sources:

What killed the dinosaurs?  http://www.ucnp.berkely.edu/diapsids/extinction.html

BBC – No fiery end
http://news.bbc.co.uk/1/hi/sci/tech/3295539.stm

Historical Geology 4th Edition by Wicander and Monroe

www.Enchantedlearning.com

The Dinosaur Extinction Page by Andrew Buckley

Gagging Galileo

2005-10-21T08:34:00.000-04:00

The year is 1633. In a dimly lit room in the middle of Rome a sickly old man, well respected by his peers, stands before the Inquisition. His crime: wanting to teach the ideas of other scientists.

Years before, in 1609, he turned his new “spyglasses” on the night sky and revolutionized the science of astronomy. He observed that the Milky Way was made up of millions and millions of stars, that the moon was not smooth or perfect and that it had mountains, that four smaller bodies revolved around Jupiter, and—possibly the most important observation—that Venus appeared to go through phases, just like the moon.

I’m no Galileo but I know what that must have felt like. Just ask anyone who talked to me while I was writing my thesis and finally began collecting data that proved my point. It didn’t matter who you were: if you asked how it was going, you were going to get an earful about infrared spectroscopic theory or the dangers of arsenic in the environment or the plight of Bangladeshi.

If you were lucky, after about five minutes I noticed the glazed-over look in your eye and let you go; if you were smart, you just cut me off. That’s the way we are, we “science people.” That passion that leads us to constantly question the world around us is only outshone by our want, our need to tell everyone else what we found. But this isn’t true just for us “science people;” this is what makes educators educators.

Back to Galileo. Galileo was not a stupid man. He lived during a time when the Church ruled the western world, a time when saying something that went against church doctrine could mean death. Galileo was, however, in some ways lucky.

Just a few years after Galileo first turned his telescope to the heavens, in 1616, he wrote a letter to the Grand Duchess Christina of Lorraine. In the letter he argued for the nonliteral interpretation of the bible—at least when a literal interpretation contradicts facts about the physical world. Furthermore, Galileo, for the first time in his professional life, claims in the letter the Copernican theory is not just a mathematical model but a physical reality.

Later that year Pope Paul V ordered the Cardinals of the Inquisition to meet and discuss the Copernican theory. On February 24th, using evidence from the theological experts of the time, the Church condemned the teachings of Copernicus and forwarded their decision to Galileo. From this point on, Galileo was forbidden from holding or teaching Copernican views.

Now about that luck: Shortly after the Inquisition made its findings, a long-time friend of Galileo, Mafeo Barberini, was elected Pope Urban VIII, and Galileo was assured that the Church would not make an issue of the Copernican theory.

For the most part scientists are not political people. We relish this idea of academic freedom; the ability to freely debate ideas and theories and most importantly to teach all ideas is what moves science. It is also what moves the modern world. But this wasn’t always the case, and we cannot forget the errors of the past, the ability of one group to control the thoughts and ideas of an entire society is not taking us forward. In fact it is holding us back.

In true debate the people control thought, and the credence of fact controls the ability of that thought to survive. Ideas, theories, concepts—they survive not because law dictates that they must but because of the will of the people to accept them based on fact and/or the general consensus of belief.

Galileo believed the same. This is why when he finally decided to make his ideas public he did so in a way that he felt would not politically harm his friend Pope Urban VIII and yet would convey his Copernican belief.

In 1624 Galileo began writing The Dialogue. The text was simple; it was debate between a believer in the Copernican (sun-centered) model of the universe and a believer in the Ptolemaic (earth-centered) model of the universe. In the end, as you can imagine, the Copernican view seems to win.

Galileo was summoned to the Inquisition.

The year was 1633, in a dimly lit room in the middle of Rome, a sickly Galileo stood accused of breaching the conditions of the 1616 Inquisition. Galileo, this time, was not able to debate the facts of his theory. The 1616 Inquisition had already declared them false. This time, Galileo was found guilty of teaching his views and was sentenced to life in prison.

Today, as educators, we still squirm at the thought of Galileo’s fate but at the same time we sit tall, empowered by the idea of academic freedom. But should we?

Recently 7,000 scientists, including 48 Nobel laureates, have signed a statement that the current government administration has willfully censored, distorted, or abused scientific data in an effort to forward a specific political agenda. The data, the statement, and the case studies can be found at www.ucsusa.org/rsi .

We can now imagine how Galileo must have felt when he found that theologians have decided that Copernicus was wrong.

As a scientist and an educator I like to think that the world has changed because of science. Science is about making progress about advancement. Turn on the TV or the radio and I guarantee that you will hear that phrase at least once in reference to some political stand point. The world is definitely different. But how has the world changed? Has the world changed so much so that we have returned to the 17th century? Shall we once again return to the days of the Inquisition, or have we already?

When Something and Nothing Means Everything

2005-08-20T16:54:00.000-04:00

Over the past year there have been countless articles circulating in newspapers and web forums debating the accuracy of our modern theory of evolution. More specifically these articles are attacking evolution and are in favor of what has come to be known as ID or Intelligent Design. As a strong believer in evolution and a scientist by profession I must say reading these articles has been, at times, excruciatingly painful. Not because the proponents of ID are speaking against evolution or even because ID relies on an Intelligent Designer, but because ID relies on the lack of information and/or in some recent articles by its proponents, both online and in print, bad science or flat-out fallacies.

In a recent article posted to Renew America, author Fred Hutchison does just that in his article “Evolution vs. Intelligent Design: which model has more integrity?” Through a couple leaps of logic he no doubtedly comes to the conclusion that proponents of ID are operating at a higher level of integrity than evolutionist. For the most part many of the ideas stated in the article are simply differences in opinion, not scientific fact, but what really got my attention was the misinformation cleverly titled, “Do evolutionists suppress facts?”

Am I part of a conspiracy? Do I finally belong to something : )

In this section of the article the author claims that evolutionist have covered up the fact that no complex animals appear in Precambrian rock. He also claims that evolutionists have suppressed information so much that many American scientists and students of science have never even heard of the Cambrian Explosion. Mr. Hutchison continues his deception by stating that, “Scientist in Communist China have significant freedom of thought and publication. Biologic science in democratic America is under the dictatorship of the evolution establishment. However, if President Bush has his way, high school children will be allowed to hear about the “Cambrian Explosion”

As a professor I don’t know a better way to rebut a statement like this than to offer the following government funded links:

PBS: Evolution Library; the Cambrian Explosion
USGS Info Bank

(I think maybe everyone but Fred Hutchison knows about this)

Before I get too annoyed, what is my point? The author lists a series of examples of “our” cover-up, most of which are inaccurate portrayals of evolutionary theory and or logical fallacies. This is the problem with the current discussion of ID. Proponents of ID have strategically taken the discussion out of the scientific realm and placed it in the layman’s lap. Now instead of experts the general public and school board officials (who are elected community members) are being asked to review scientific theories. I wonder if we will do the same for new theories in medicine.

Is evolution a perfect theory? No, but so far it is the best scientific theory we have. Proponents of I.D. consistently point to the so called holes or gaps in evolution theory and claim that because science has yet to answer some questions the whole theory must be flawed. This is simply not true, and the whole idea behind science is wrapped tightly within that very statement. Science is yet to answer some questions, not because we can't ever answer them but because we are still learning and our technology is still improving. Our answers are only as good/current as our technology.

Natural History Magazine: Intelligent Design is a wonderful article that presents the views of three proponents of ID followed by a rebuttal from a proponent of evolution.

Intelligent Design Network

The National Center for Science Education

In the Beginning: Compelling evidence for Creation

Study: Volcanic warming may have caused extinction

2005-01-20T06:04:00.000-05:00

Thursday, January 20, 2005 Posted: 3:04 PM EST (2004 GMT)

WASHINGTON (AP) -- An ancient version of global warming may have been to blame for the greatest mass extinction in Earth's history.

In an event known as the "Great Dying," some 250 million years ago, 90 percent of all marine life and nearly three-quarters of land-based plants and animals went extinct.

Scientists have long debated the cause of this calamity -- which occurred before the era of dinosaurs -- with possibilities including such disasters as meteor impacts.

Researchers led by Peter Ward of the University of Washington now think the answer is global warming caused by volcanic activity. Their findings are reported in Thursday's online edition of the journal Science.

They studied the Karoo Basin of South Africa, using chemical, biological and other evidence to relate layers of sediment there to similar layers in China that previous research has tied to the marine extinction at the same period.

Studying a 1,000-foot thick section of exposed sediment, Ward's team found evidence of a gradual extinction over about 10 million years followed by a sharp increase in extinction rate that lasted another 5 million years.

Ward's team believes the extinctions were caused by global warming and oxygen deprivation over long periods of time.

Massive volcanic flows in what is now Siberia brought on the warming while, at the same time, geologic action caused global sea levels to drop, Ward explained in a telephone interview.

"Once you expose a huge amount of underwater sediment to the atmosphere, two very bad things happen -- a huge amount of carbon in the sediments is released and also methane. Once (methane) hits the atmosphere it's the most efficient greenhouse gas on the planet," he said.

That provided a one-two punch of warming and a decline in oxygen levels, he said.

"Some of us have been toying with the idea that dinosaurs evolved to be a low-oxygen adaptation," resulting from this era, Ward said. "We know birds can live at much lower oxygen concentrations than we do, and we and think there were similar lung adaptations in dinosaurs."

Currently the atmosphere consists of about 21 percent oxygen, but the addition of gases at that time could have lowered levels to 16 percent or less, Ward said.

"If you didn't live on the sea level you didn't live," he commented, reflecting the fact that oxygen concentrations decline with altitude. The result would have been to eliminate half the living space on the planet, said Ward.

Scientists theorize dinosaurs evolved from the Earth's " Great Dying."
The more recent mass extinction that killed the dinosaurs -- 65 million years ago -- has been linked to an impact by a large asteroid or comet that struck in an area off the coast of what is now Mexico and left a distinctive layer of dust worldwide.

Some researchers have argued that the Great Dying might also have resulted from such an impact, but Ward's team said it could find no evidence for such an event.

That doesn't mean there wasn't one, argues Luann Becker of the University of California at Santa Barbara, commenting that "the absence of evidence isn't evidence for absence."

Becker, who was not part of Ward's research team, said "they did a nice job of presenting the paleontological data and the stratigraphy, which seem to show some indication of an evolutionary change going on for a prolonged period of time." However, she added, she doesn't believe that addresses the subject of cause and effect.

"I think that this is an ongoing discussion," said Becker, who previously reported on a crater off the northwest coast of Australia that shows evidence of a large meteor impact at about the time of the early extinction.

Ward's research was funded by the NASA Astrobiology Institute, the National Science Foundation and the National Research Foundation of South Africa.

Bones of prehumans dated to 4.5 million years

2005-01-19T05:09:00.000-05:00

Wednesday, January 19, 2005 Posted: 2:09 PM EST (1909 GMT)

(AP) -- Paleontologists working in Ethiopia have discovered the remains of at least nine primitive human ancestors that are up to 4.5 million years old.

The specimens belong to a hominid species called Ardipithicus ramidus, a transitional creature with significant ape characteristics. The fossils are mostly teeth and jaw fragments, with some hands and feet bones, according to nine researchers from universities in the United States and Spain.

The discoveries were made over a four-year span beginning in 1999 in digs at the As Duma site in Ethiopia's Afar region, which has yielded many important fossils. The details appear in the latest issue of the journal Nature.

Among the specimens, the recovered canine teeth are smaller and blunt, similar to those of other human ancestors. But most of its teeth, including molars, are like those of great apes. The size and wear of the teeth suggest A. ramidus ate a plant-based diet, the researchers reported.

Geological and radiocarbon tests show the specimens are between 4.3 million and 4.5 million years old.

Scientists know little about A. ramidus. A few skeletal fragments suggest it was even smaller than Australopithecus afarensis, the 3.6 million-year-old species widely known by the nearly complete "Lucy" fossil that measures about four feet tall.

Evidence from other A. ramidus specimens shows its skull rested directly atop its spinal column, rather than in front like apes. This suggests it could walk upright, or had bipedal abilities.

Other fossils found at the As Duma site show that A. ramidus lived alongside monkeys, mole rats and cow-like grazing animals. But details of the environment are sketchy.

Originally, scientists theorized that the earliest human ancestors lived on the savannah and began walking upright to see across the open landscape. But pollen and other evidence from As Duma suggest the diverse habitat had swamps, grass and even some woods.

The first A. ramidus fossils were reported in 1994. With the nine additional specimens, labs now have fragments from as many as 60 individuals.