"(Tape) We became very curious about this because this impact feature, if it was an impact feature, could be fairly recent -- it could be as recent as 5 to 10,000 years before the present."
Posted on 09/09/2002 5:45:16 AM PDT by blam
Source: NASA/Goddard Space Flight Center
(http://www.gsfc.nasa.gov/)
Date: Posted 9/9/2002
NASA Scientists Determined To Unearth Origin Of The Iturralde Crater
NASA scientists will venture into an isolated part of the Bolivian Amazon to try and uncover the origin of a 5 mile (8 kilometer) diameter crater there known as the Iturralde Crater. Traveling to this inhospitable forest setting, the Iturralde Crater Expedition 2002 will seek to determine if the unusual circular crater was created by a meteor or comet. Organized by Dr. Peter Wasilewski of NASA's Goddard Space Flight Center, Greenbelt, Md., the Iturralde Crater Expedition 2002 will be led by Dr. Tim Killeen of Conservation International, which is based in Bolivia. Killeen will be assisted by Dr. Compton Tucker of Goddard. The team intends to collect and analyze rocks and soil, look for glass particles that develop from meteor impacts and study magnetic properties in the area to determine if the Iturralde site, discovered in the mid-1980s with satellite imagery, was indeed created by a meteor.
If a meteorite is responsible for the impression, rocks in the area will have shock features that do not develop under normal geological circumstances. The team will also look for glass particles, which develop from the high temperatures of impact.
The Iturralde Crater Expedition 2002 team will extensively analyze soil in the impact zone for confirmation of an impact. One unique aspect of the Iturralde site is the 4-5 km deep surface sediment above the bedrock. Thus the impact was more of a gigantic "splat" rather than a collision into bedrock.
The large crater is only 1 meter lower in elevation than the surrounding area. Water collects within the depression, but not on the rim of the crater, which is slightly higher than both the surrounding landscape and the interior of the crater. These subtle differences in drainage are reflected in the forest and grassland habitats that developed on the landscape. It is precisely these differences in the vegetation structure that can be observed from space and which led to the identification of the Iturralde Crater in the 1970s when Landsat Images first became available for Bolivia.
Impact craters can also be confirmed through the magnetic study of the impact zone. Dr. Wasilewski's team will conduct ground magnetometer surveys and will examine the area through an unmanned aerial vehicle plane fitted with a magnetometer, an instrument for measuring the magnitude and direction of magnetic field. The resulting data will be analyzed by associating the magnetic readings with geographical coordinates, to map magnetic properties of the area. The magnetometer data could provide conclusive evidence as to whether or not the Iturralde feature is an impact crater.
The Iturralde Crater Expedition 2002 expedition also contains an education component. Teachers from around the world who are involved with the teacher professional development program, called Teacher as Scientist, have helped to design the expedition. One teacher will actually be on-site assisting with data collection.
University students from Bolivia will also be involved in the expedition. The educational element of the expedition is just as important as the science results," said Goddard engineer Patrick Coronado. "This is one of those experiments that stirs the imagination, where science and technology come head-to-head with nature in an attempt to unlock its secrets."
More information on ICE2002 can be found on http://www.blueiceonline.org
Editor's Note: The original news release can be found at http://www.gsfc.nasa.gov/topstory/20020904icecrater.html
"(Tape) We became very curious about this because this impact feature, if it was an impact feature, could be fairly recent -- it could be as recent as 5 to 10,000 years before the present."
The Araona Crater
The Araona Crater (also known as the Iturralde Structure) is a suspected crater from an impactor which struck northern Bolivia approximately 20,000 years ago. The feature is believed to have been caused by a short period comet striking at 70 kilometres per second and splattering into the muddy alluvial flood plain in the Lower Amazon jungle. The impact created a circular depression which is now roughly 8 kilometres across and 3 metres deep. The structure was discovered in 1988 LandSat data, but was not visited successfully until 1998 because the region is inaccessible. Future expeditions hope to finally settle if the feature truly is the impact crater it appears to be, and if so, determine the nature of the impactor.
The full LandSat scene of Northern Bolivia includes the Rio Bene running northward through the image (North is up), with the Rio Madidi running across the image from southwest towards the northeast before joining the Rio Bene. The image was constructed from LandSat Thematic Mapper bands 7, 5, and 3 displayed as red, green, and blue respectively. The green tone of the image distinguishes between different types of vegetation with low scrubland in the alluvial flood plain appears as a light green and dense tropical jungle coverage appearing dark green. The close-up of the impact crater uses the same LandSat data, but passed through a sharpening image filter which emphasizes high spatial frequency features and tends to enhance colour contrast.
Carolina Bays
The argument is still raging. There are about 500,00 of these up and down the east coast of the US, there does seem to be some alignment.
How could they know the difference? Do they know the difference between meteor and and meteorite or between asteroid and comet? Does NASA give science writing assignments to freshman staff not yet qualified to write for the sports page?
I don't know the answer to either of your questions but you know that everything has been 'dumbed down' so that every one will feel better.
I read something like that also and it said that they were Caucasian. Maybe I read it in the Red Record?
I'd never seen them before.
For all the world, they look like any cluster of pivot sprinkler fields in West Texas, Oklahoma and Kansas.
Absolutely identical.
A close up of a Carolina Bay. They aren't 'sprinkler fields.' Most of them are like small swamps.
...5 mile (8 kilometer) diameter crater... One unique aspect of the Iturralde site is the 4-5 km deep surface sediment above the bedrock. Thus the impact was more of a gigantic "splat" rather than a collision into bedrock. The large crater is only 1 meter lower in elevation than the surrounding area.thanks blam. Old topic, people.
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