Geology News - Earth Science Current Events

The Vredefort Dome is Earth's largest and oldest clearly visible meteorite structure. It is approximately 250 kilometers in diameter and is thought to be about 2 billion years old. This South Africa location is one of 50 sites that have been nominated for World Heritage Site Status. Selected sites will be announced at the UNESCO World Heritage Conference next month. See our article on the Vredefort Dome to learn more.

South Africa already has six World Heritage sites: Robben Island in the Western Cape (prison buildings here symbolize the triumph of the human spirit, of freedom, and of democracy over oppression), the Cradle of Humankind in Gauteng and North West (includes the fossil hominid sites of Sterkfontein, Swartkrans and Kromdraai), the Greater St Lucia Wetland Park in KwaZulu-Natal (fluvial, marine and aeolian processes here have produced a variety of landforms, including coral reefs, long sandy beaches, coastal dunes, lake systems, swamps, and extensive reed and papyrus wetlands), the uKhahlamba Drakensberg Park in KwaZulu-Natal (rock art paintings made by the San people over a period of 4000 years); the Mapungubwe Cultural Landscape in Limpopo (once the largest kingdom in the African Subcontinent before it was abandoned in the 14th century); and the Cape Floral Region of the Western Cape (an area of enormous species diversity - less than 0.5% of the area of Africa but supports nearly 20% of the continent’s floral species).


Image created using NASA Landsat Geocover Data

Labels: Meteor-Meteorite

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Most geologists believe that diamonds form in Earth's mantle from inorganic carbon. This is contrary to the widespread idea that diamonds are formed from the metamorphism of coal. Two reasons that most geologists shun the "diamonds from coal" origin are: 1) the temperatures and pressures required to form a diamond are only found at depths of over 100 miles - far deeper than any coal seam has been buried; and 2) the source rock for diamonds is kimberlite - an igneous rock.

An article on the Discovery.com website reports that recent work done by Ralf Tappert and colleagues suggests that diamonds from the Jagersfontein mine in South Africa are enriched in carbon-12, the isotope of carbon that is characteristic of living things. Tappert's theory is that the diamonds from Jagersfontein might have formed when a slab of oceanic crust, containing the carbon-bearing remains of marine organisms, was subducted to a depth sufficient for the formation of diamonds. Read more about this new idea about How Diamonds Form at the Discovery.com website.

Labels: Diamonds

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Record flooding levels have resulted in over 500 deaths and 2,000,000 evacuations in southern China. The Pearl River is at record levels and significant damage has occurred in the Guangdong Province. Visit the Los Angles Times website to learn more about Record Flood Levels in China.

Labels: Floods-Flooding

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The United Nations Environment Programme has released "One Planet Many People: Atlas of Our Changing Environment". This atlas documents, through the use of 80 spectacular satellite image pairs, 30 case studies and numerous maps, how our planet is changing, mainly in result to the pressures of humans on the environment. A pdf copy and other information can be viewed on the web at the United Nations Environmental Programme Website.

Labels: Global-Warming, Satellite-Images

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The Association of Bay Area Governments has an online GIS that serves a variety of different hazard maps. The most timely are tsunami evacuation maps for San Francisco and adjacent areas of California. Shakemaps, liquifaction maps, flooding maps, landslide maps and wildfire maps can also be produced on their website. Visit the ABAG site to view their "Tsunami Evacuation Maps".


Available on geology.com are two articles: What Causes a Tsunami? and Indonesia Tsunami Maps.

Labels: Tsunamis

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Two recent articles in online editions of Seattle newspapers point out how the recent earthquakes that occurred off the California coast may have triggered some rethinking of current monitoring and emergency response procedures. One article is in the Seattle Times and the second in seattlepi.com.

The June 14th 7.0 magnitude earthquake did not produce a dangerous tsunami because it had the wrong type of motion. It was produced by strike-slip motion instead of the vertical motion which displaces large amounts of seawater. See our article: "What Causes a Tsunami" for an illustrated explanation of the motion typically associated with a damaging tsunami.

Labels: Tsunamis

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Dr. William A. Bowen of the California Geographical Society has published an atlas of aerial images for the state of Oregon. These images are mathematically created from satellite data to yield a low-angle panorama of the landscape. The Oregon Atlas is the fifth in a series which include: Alaska, California, Nevada, Oregon and Washington. Access to this information can be obtained at the Electronic Map Library.

Labels: Maps

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NOAA has posted a collection of Hurricane Track Maps for the Atlantic and Gulf states. These maps show cumulative hurricane tracks all storms which have passed over or within ten nautical miles of the state's border since 1851. Hurricane track maps can be viewed for Alabama, Connecticut, Delaware, Florida, Georgia, Louisiana, Maine, Maryland, Massachusetts, Mississippi, New Hampshire, New Jersey, New York, North Carolina, Rhode Island, South Carolina, Texas and Virginia. Read more about Hurricane History and Hurricane Track Maps at the NOAA website.

Labels: Hurricanes

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A major earthquake occurred on June 14th (local date), 2005 off the coast of northern California. The 7.0 magnitude earthquake prompted a tsunami watch, which was quickly lifted, and some precautionary evacuations in the Crescent City area. Read more about the California Earthquake at the USGS website.

Image from USGS

Labels: Earthquakes

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A major earthquake occurred on June 13th, 2005 in the Tarapaca, Chile region. Read more about the Tarapaca,
Chile Earthquake.

Labels: Earthquakes

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There is new eruption activity at Colima Volcano in Mexico. Colima is considered to be Mexico's most active and dangerous volcano. The latest eruption sequence began on May 24th and the strongest eruption in the past 20 years occurred on June 3rd. The images of Colima Volcano shown below are from the Earth Observatory website. Visit there to learn more about this eruption of Colima Volcano and to see the same images in greater detail.

Labels: Volcanoes

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The United States Geological Survey has published a number of preliminary soil-slip susceptibility maps for southwestern California. These maps show relative susceptibility of hill slopes to the initiation of rain-triggered soil slip-debris flows. The maps were created by considering slope, bedrock characteristics, and the presence of historic landslide problems in each study area. The timing of landslides is determined mainly by precipitation. Read about these landslide hazard maps at the USGS website.

Labels: Landslides

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A large landslide has closed the southbound lane of US Route 15 between Tioga and Mansfield in Tioga County, Pennsylvania. The slide has been moving slowly for the past several months. The first photo below is looking north and shows the head of the slide as a depression in the highway. The second photo, looking south shows fractured pavement in the scarp zone. Photos submitted by Kevin Thomas of KC101.5 FM Radio.

Labels: Landslides

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A very good article titled "Truth Fiction and Everything in between at Yellowstone" has been published on the Geotimes website. This article was written by one of the most credible people on this subject, Jake Lowenstern, scientist-in-charge for the Yellowstone Volcano Observatory. The goal of this article is to set the record straight on past and future eruptions at the Yellowstone Caldera. The observatory is based at Menlo Park, California. It is a partnership between Yellowstone National Park, USGS and its Volcano Hazards Program, and the University of Utah, which operates the earthquake and ground-deformation monitoring networks. Read about Volcanic Eruptions at the Yellowstone Caldera.

Labels: Volcanoes

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