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

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

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

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

Yellowstone National Park/Super Volcano

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?

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

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.

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

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

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

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

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.