Geology News - Earth Science Current Events

The University of Tromsø (Norway) has a very nice website with flash animated tutorials on many geology topics. These modules are rich in animations, illustrations, photos and text. Topics available include: minerals, rocks, magmatism, volcanoes, metamorphic rocks, structural geology, absolute age, earthquakes, Earth's interior, plate tectonics, mountain building, mineral resources, geochronology and more. Nice work!

Image by WebGeologyLearn more at WebGeology.

Labels: Teaching-Science

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Mount Merapi, a stratovolcano on the Indonesian island of Java is threatening eruption. The area around Merapi has a high population density. Hundreds of small villages surround the volcano and the province capital of Yogyakarta (home to over 1,000,000 people) is only 18 miles south of the volcano.

Merapi has erupted several times this century, sometimes with deadly impact. Lahars and pyroclastic flows have devastated agricultural areas and caused fatalities on the western flank of the mountain. Scars from these lahars can be seen in the Landsat image below. The most deadly event was in 1930 and killed over 1000 people.


Image by geology.com using NASA Landsat dataRead more at ReliefWeb.

Labels: Volcanoes

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The 1815 eruption of Mount Tambora on the Indonesian island of Sumbawa was the largest volcanic eruption in Earth's recorded history. It ejected about 50 cubic kilometers of magma and left a deep caldera in the location where a large stratovolcano had stood. Earthquakes from the eruption were felt at Surabaya, approximately 500 kilometers away.

The impact of this eruption was global. The powerful eruption launched millions of tons of fine volcanic dust and gases into the atmosphere. Atmospheric circulation disseminated the dust and gases throughout the stratosphere. This significantly reduced the amount of sunlight which reached the Earth and resulted in a temporary decline in global temperatures by as much as 3° C. For nearly a year, most of the northern hemisphere experienced sharply cooler temperatures and the calendar year 1816 has been referred to as the "the year without a summer."

A village believed to have been covered by the Tambora eruption has recently been discovered and is now being called "The Pompeii of the East"

Read more in a National Geographic Article.

Labels: Volcanoes

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Three news releases from the National Center for Atmospheric Research and MIT provide information that supports the idea that global warming will produce more powerful hurricanes - both in number and in storm strength.

• Hurricanes are getting stronger - NCAR
• Hurricanes growing fiercer with global warming - MIT
• Hurricanes to intensify as Earth warms - NCAR

Images from NASA

Labels: Global-Warming, Hurricanes

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A diamond the size of a "hen's egg" has been found in alluvial deposits of South Africa by Nare Diamonds Limited. The 235 carat diamond is an octahedron of very good quality. Diamonds of this size are very rare, although much larger have been found in the past. The world record diamond was found by De Beers in 1905 with a weight of 3106 carats.

Read more and see a photo of the stone at Yahoo! News.

Labels: Diamonds

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April 18th is the 100th anniversary of the 7.8 magnitude San Francisco Earthquake, the most deadly earthquake in United States history. The epicenter was about two miles offshore and this earthquake caused extensive damage throughout the city. Landslides, liquifaction and breakage of utility lines were responsible for much of the damage. This earthquake was one of the first to strike a city with an extensive utility infrastructure. Broken gas lines were responsible for many severe fires and broken water lines rendered the most effective fire-fighting tools useless.


Testimony page from the National Archives - Herman Schussler, Chief Engineer - Spring Valley Water Works

Here are some of the top resources on the web if you would like to learn more about this event.

National Archives - Collection of Letters and Testimony Transcripts

SFGate.com - Collection of Articles

National Geographic - San Francisco's 1906 Quake: What If It Struck Today?

Labels: Earthquakes

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An Associated Press article states that the demand for geologists is double the supply. This shortfall in supply is caused by three factors:

1. High oil prices
2. Lots of oil company geologists are nearing retirement age
3. Small numbers of geology graduates

Read the entire story about Demand for US Geologists at the Dallas Morning News website. (Viewing the article is free but registration is required.)

Labels: Employment

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The Hubble Space Telescope has refined the size of Xena, the tenth planet. Ground based estimates were about 25% too high. Hubble's new estimate of Xena's diameter is about 1490 miles +/- 60 miles. This makes it approximately the same size as Pluto, which is 1422 miles.

"Hubble is the only telescope capable of getting a clean visible-light measurement of the actual diameter of Xena," said Mike Brown, planetary scientist at the California Institute of Technology in Pasadena, California and leader of the team that discovered the tenth planet.

Xena's high reflectivity was part of the reason for the inaccurate ground-based size estimate. Since it is smaller than previously thought, it must be one of the most reflective objects in the solar system. The only object more reflective is Enceladus, a geologically active moon of Saturn whose surface is continuously recoated with highly reflective ice by active geysers.

Xena's bright reflectivity is possibly due to fresh methane frost on its surface. This methane could be discharged from the planet's interior to freeze on the surface.


Image by NASA, ESA, and A. Feild (STScI)Read more about estimating the size of the tenth planet.

Labels: Planets

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Three members of a ski patrol team at Mammoth Mountain, California were asphyxiated by carbon dioxide gas at a vent where they were installing plastic fencing to keep other skiers away. The vent is on the Christmas Bowl run and is known as the "stink hole" because of the bad-smelling gases.

Carbon dioxide gas has been a problem at Mammoth Mountain in the past. Large volumes of gas have seeped through the soil and have killed many trees throughout an area of about 100 acres. (The trees need to absorb oxygen directly from the soil and the soil gases in some areas have been largely displaced by carbon dioxide.) These emissions have not caused problems for people as the carbon dioxide is quickly dissipated when it escapes from the soil.

Mammoth Mountain is a young volcano on the southwest rim of Long Valley Caldera, a large volcanic depression in eastern California. It has been volcanically active for about 4 million years. The most recent volcanic eruptions in the region occurred about 200 years ago, and earthquakes frequently shake the area. Because of this, the U.S. Geological Survey (USGS) operates an extensive network of instruments to monitor the continuing unrest in the Long Valley area.

Read more details about the skiers in an Associated Press story at SFGate.com. Learn more about Mammoth Mountain and previous carbon dioxide emissions at the Long Valley Observatory website.

Labels: Volcanoes

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Paleontologists have discovered a fossil fish that bridges the evolutionary gap between fish and land animals. This new species has the fins and scales of a fish, but parts of the fin resemble the limbs of tetrapods, some of the earliest limbed animals.

The fossil was found in Devonian rocks on Ellesmere Island in Canada's Nunavut Territory. It has been named Tiktaalik (large, shallow-water fish) by the people of Nunavut. During the Devonian, what is now Ellesmere Island was part of a landmass located near the equator and with a subtropical climate. The rocks that Tiktaalik was discovered in were deposited by streams meandering across a wide floodplain.

Farish Jenkins of Harvard University sums up the importance of this fossil: "The skeleton of Tiktaalik indicates that it could support its body under the force of gravity whether in very shallow water or on land, this represents a critical early phase in the evolution of all limbed animals, including us."


Zina Deretsky, National Science FoundationRead more about Tiktaalik at the NSF website.

Labels: Fossils

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The typical culprits that are pointed at for Louisiana subsidence are: sediment compaction, ground water production, salt evacuation, organic sediment decomposition due to drainage projects and petroleum production. A study by Roy Dokka of the Department of Civil & Environmental Engineering, Louisiana State University and submitted as testimony to the Subcommittee on Water Resources, Committee on Transportation and Infrastructure, places significant blame for recent subsidence on the Michould Fault, a normal fault that trends beneath the eastern portion of New Orleans.

The document provides a good overview of the causes of subsidence, a summary of subsidence history, and subsidence-causing activities in the New Orleans area. It also points out that accurate elevation measurements in the New Orleans area are difficult to produce because the current system of benchmarks has been rendered inaccurate because of subsidence. These poor measurements make current highway elevations inaccurate, FEMA flood maps inaccurate and NOAA storm surge models inaccurate. Future construction projects will also be jeopardized by inaccurate data until the benchmarks are updated and maintained.


Image from House Testimony - Michould Fault Shown as "MF" - note subsidence adjacent to fault.
The transcript is only about ten pages long and is not extremely difficult reading. Please see: Effect of Subsidence on Flood Protection Options and Water Resources Planning in the Gulf Coast, testimony by Roy K. Dokka.

Labels: Subsidence

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