Geology News - Earth Science Current Events

NASA Climate Change Animation - click image to view.

NASA reports that 2006 was the fifth warmest year on record and 2007 will likely be even warmer - possibly the warmest year in the history of instrumental measurements. Over the past 30 years Earth has warmed by about 0.6 degrees Centigrade or 1.08 degrees Fahrenheit.

NASA has documented this increase with an animation. The first and last frames of their climate change animation can be seen in the image at right. It shows the increase in annual mean temperature in one year increments between 1880 and 2006.

When watching the animation you will see that temperatures have warmed at nearly all locations worldwide and that the greatest temperature changes have occurred in very high latitudes. Since the largest changes have occurred in areas where there are very few people this suggests that the warming is not due to local effects of heat pollution by people, but is instead a global climate change. A graph of global-mean surface temperature change for the same time period is shown in the graph below.

"Climate Change" Graph - Image by NASA

Labels: Arctic-Antarctic, Global-Warming

---

Researchers in a NASA/NSF/NOAA funded study have identified connections between high latitude volcanic eruptions and periods of low water flow in African rivers. Using computer models they linked Iceland's Laki Volcanic Event (a series of about ten eruptions that occurred between June 1783 and February 1784) to the lowest water levels in the Nile River in a historical record dating back to 622 AD.

Using computer models developed by NASA they found that the Laki Volcanic Event altered surface temperature patterns that produced extremely low levels of rainfall across much of Africa. The initial atmospheric response to the eruption was a decline in global temperatures. This temperature decline produced a reduced temperature difference between land and ocean. Without that temperature contrast, onshore winds weakened and the delivery of moisture and rainfall from the ocean was severely reduced.

Following a volcanic eruption, large amounts of sulfur dioxide (SO2), hydrochloric acid (HCL) and ash are spewed into the Earth's stratosphere. In most cases, HCL condenses with water vapor and is rained out of the volcanic cloud. SO2 from the cloud is transformed into sulfuric acid. The sulfuric acid quickly condenses, producing aerosol particles which linger in the atmosphere for long periods of time. Image and description by NASA/LaRC

In addition to low flows on the Nile River during 1783 and 1784 in response to the Laki Volcanic Event, low water levels were observed on the Niger River after the Novarupta eruption of 1912, and on the Nile River after the Eldgia (Iceland) eruption of 939 AD.

Read more at about the climate impact of high latitude volcanic eruptions at the NASA website.

Labels: Arctic-Antarctic, Volcanoes

---

Scientists from Case Western Reserve University, who have a strong track record recovering meteorites in Antarctica, have discovered that one of their specimens found in 2005 is a piece of Earth's Moon. The specimen was found by members of the U.S. Antarctic Search for Meteorites program on an icefield in the Miller Range of the Transantarctic Mountains, roughly 750 km from the South Pole. The lunar meteorite weighs 142.2 grams and is slightly larger than a golf ball. The specimen was broken to allow a close study of its composition and texture. Pieces of the specimen will be shared with scientists at research centers around the world.


The meteorite is a coarse-grained gabbro that is similar in composition to lunar basalts that fill the lunar maria. However, the large crystal size suggests that this rock cooled within the Moon's interior. The cube in the image is one cubic centimeter in size. Image by NASA's Johnson Space Center.


Polarized light photomicrograph of part of the lunar meteorite. The bright, highly fractured material is pyroxene and the smoothly textured dark gray material is maskelynite, a mineral formed from the vitrification of plagioclase by shock melting. Image by NASA's Johnson Space Center.

Read more about the Lunar Meteorite at the Case Western Reserve Blog.

Labels: Arctic-Antarctic, Meteor-Meteorite

---

Map of the Arctic Ocean and North Pole. Image by CIA

The North Pole is often thought of as a place that is inaccessible - unless you have a submarine or the ability and courage to travel there over the ice. Satellite images taken last month from ESA's Envisat and EOS Aqua satellites show that the Arctic Ocean was clear enough of ice that a ship could sail from locations in northern Europe directly to the North Pole.

This adds to the accumulating evidence that the northern polar ice cover is shrinking as a result of global warming. There are many downsides to global warming but a tiny upside would be opening of The Northwest Passage, a sea route connecting the Atlantic and Pacific Oceans through the Arctic Archipelago of Canada and the Northern Sea Route, a shipping lane between the Atlantic and Pacific Oceans along the northern margins of Europe and Asia.

Read the full article on Ice in the Arctic Ocean at Yahoo! News.

Labels: Arctic-Antarctic, Global-Warming, Oceanography

---

Stories about global warming and melting glaciers are showing up in the news everywhere. There must be something to the idea of global warming if numerous investigators are observing glaciers are melting and in consistent retreat in countries worldwide.


Image composed by Geology.com using NASA Landsat data

Here is a sampling of story titles that have appeared over the past few years on the BBC website.

  Europe's glaciers in retreat - 6 Sep 2006
  'Major melt' for Alpine glaciers - 4 Apr 2006
  Earth - melting in the heat? - 7 Oct 2005
  Peru's glaciers in retreat - 25 Aug 2005
  Glaciers in Antarctic 'shrinking' - 21 Apr 2005
  Antarctic glaciers show retreat - 21 Apr 2005
  Himalayan glaciers 'melting fast' - 14 Mar 2005
  Greenland ice-melt 'speeding up' - 28 Jul 2004
  Patagonian ice in rapid retreat - 27 Apr 2004
  South American glaciers' big melt - 17 Oct 2003
  Melting glaciers threaten Peru - 9 Oct 2003
  Kazakhstan's glaciers 'melting fast' - 4 Sep 2003
  Antarctica's ice sheet melting naturally - 3 Jan 2003
  Bolivian glaciers shrinking fast - 10 Dec 2002
  Record ice loss in Arctic - 9 Dec 2002
  Photos show glacier's decline - 8 Aug 2002
  Antarctic ice fringe 'melting faster' - 13 Jun 2002
  Rapid Antarctic warming puzzle - 6 Sep 2001
  Warm-up in the Alps - 26 Aug 2001
  Alpinism: Then and now - 26 Aug 2001
  Kilimanjaro's white peak to disappear - 19 Feb 2001
  Antarctic ice sheet shrinks - 1 Feb 2001
  Earth enters the big thaw - 7 Mar 2000
  Antarctic ice crumbling rapidly - 8 Apr 1999
  The thawing of Alaska - 10 Nov 1998

Any of these stories and more can be found at the BBC website. Here is a link if you want to read any of these articles or check for yourself... "glaciers + retreat".

Labels: Arctic-Antarctic, Glaciers, Global-Warming

---

Ohio State University scientists have discovered a possible meteor impact crater beneath the ice of East Antarctica in the Wilkes Land area. Gravity measurements suggest that the impact forming this crater occurred about 250 million years ago - about the same time as the Permian-Triassic Extinction - the most significant extinction in Earth's history that wiped out most plant and animal species.

This crater is approximately 300 miles wide (twice as wide as the Chicxulub Crater that is often credited as killing the dinosaurs about 65 million years ago) and is hidden beneath over one mile of ice. It is possible that the force of this impact triggered the break-up of the Gondwana Supercontinent.

The crater was identified using gravity and radar data. The first image below shows GRACE-measured gravity fluctuations beneath East Antarctica. Denser regions appear more red; the location of the Wilkes Land crater is circled. The bottom is an airborne radar image of land elevation in East Antarctica . Higher elevations appear red, purple, and white; the raised rim of the crater is circled. An inset of the Chicxulub crater is included for size comparison.


Image courtesy of Ohio State University.


Image courtesy of Ohio State University.

Read more about the Antarctic Meteor Crater at the Ohio State University website.

Labels: Arctic-Antarctic, Meteor-Meteorite

---

A feature article at the Geotimes website gives details on several Antarctic drilling projects. These have been done in part to understand the climate history of the Antarctic region. This drilling has focused on recovering ice cores, sea-floor sediments and shallow geologic materials. The hope is to collect evidence of past climate history and use that informatoin to understand future climate change.
Read more about Antarctic Drilling at the Geotimes website.

Labels: Arctic-Antarctic

---

CBC News Online has posted an interesting feature and interactives on the topic of global warming and Arctic climate change. The site is rich with photos, audio, video and slideshows. Topics include: ice breakup, fewer gulls, warmer lakes, bio-invaders, ice melt, polar bears, warmer winters, permafrost, boreal, beetles invade, forest fires, tree ring records, carbon trap, sea rise and more.

Screenshot from CBC NewsLearn more about Arctic Climate Change at the CBC website.

Labels: Arctic-Antarctic, Global-Warming

---

Researchers are learning about the sounds beneath the Southern Ocean which surrounds Antarctica. A team from the Oregon State University Hatfield Marine Science Center will record sounds in an area of the Bransfield Straight, between the Antarctic Peninsula and the South Shetland Islands. Their hope is to record moving ice sheets, undersea earthquakes and volcanoes, and vocalizations of baleen whales.

Southern Ocean Map by CIA Factbook.Read more about this Southern Ocean research at the Newport News-Times website.

Labels: Arctic-Antarctic, Volcanoes

---