Geology News - Earth Science Current Events

High concentrations of inorganic arsenic have been found in New England ground waters. In addition, higher than average mortality rates from bladder cancer in males and females have been experienced in the same areas. These have prompted USGS to conduct a detailed study and publish "Modeling the Probability of Arsenic in Groundwater in New England as a Tool for Exposure Assessment".

The map below shows locations of wells and concentrations of inorganic arsenic. The larger the circle the more arsenic in the water sample - note that many of these wells exceed the arsenic drinking water standard of ten micrograms per liter.


Image by USGS

The next map shows the probability of a ground water well having a dissolved arsenic content of greater than five micrograms per liter. This map was produced using the predictive model developed as part of the USGS study. USGS scientists concluded that specific rock types, high arsenic concentrations in stream sediments, proximity to intrusive granitic plutons, and hydrologic and landscape variables relating to groundwater residence time increase the probability of arsenic occurrence in groundwater. Before this study it was believed that high concentrations of inorganic arsenic in New England ground waters were caused by past arsenic pesticide use.


Image by USGS

Read the full Arsenic in New England Ground Water Report at the USGS Website (.pdf)

Labels: Ground-Water

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Dimension stone is a natural rock material that is produced in regularly-shaped blocks or thin slabs for use in construction and landscaping. The past few years have seen a sharp increase in the use of dimension stone within the United States.

Image by National Park Service	Image by USAid.gov
	Image by USAid.gov

Apparent consumption has grown steadily since 2001 as illustrated in the table below.

Year	2001	2002	2003	2004	2005
Domestic Production	263	254	268	281	285
Import for Consumption	1070	1190	1390	1790	2400

Leading producer states are Indiana, Vermont, Wisconsin, South Dakota and Georgia, while most imports are from Italy, India, Canada and Spain. Granite, limestone, sandstone, marble and slate are the primary rock types used.

The United States Geological Survey attributes the increase in dimension stone use to increasing interest from the new construction and refurbishment sectors where dimension stone is used for construction, flagging and curbing. The upward trend is expected to remain for at least the next five years.

Read more about Dimension Stone at the USGS website.

Labels: Minerals

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Bentonite production is rising rapidly at many locations in the United States. High fuel prices are driving extensive exploration for oil, natural gas and coal-bed methane. All of this drilling requires the use of bentonite as a drilling mud. This high density mud is circulated down the well to cool the drilling tools and deliver cuttings to the surface.

In addition, more and more people are choosing to keep pets indoors and this activity drives the demand for pet waste absorbents; bentonite can absorb water equivalent to several times its weight. Although drilling muds and pet waste absorbents are the two main uses for bentonite, it is also used in a wide variety of applications. These include: foundry sand, iron ore pelletizing, sealing and waterproofing, animal feed, cosmetics, and clarifying, decolorizing, and filtering liquids.


Image by USGSAn interesting article at Missoulian.com details the rising demand for Wyoming bentonite and the many ways that the mineral is used.

Labels: Minerals

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The United States Geological Survey has released a new publication: "Characteristics of Thermal Springs and the Shallow Ground-Water System at Hot Springs National Park, Arkansas". This report summarizes the geology, history and value of these thermal springs and is free to download from the USGS website.

The thermal springs emerge from a gap between Hot Spring Mountain and West Mountain in central Arkansas and are fed by deep thermal ground water flow along with a component of cold, shallow water. They yield over 500,000 gallons per day of water that is approximately 60 degrees Celsius. The water begins as surface recharge and descends to a depth of over one mile where it is heated before rising back to the surface through a deep fracture system.

The research undertaken to produce this report was done to understand the springs, monitor changes, and evaluate the ground water system that supports the springs. This information is important for protecting the springs and preserving them for future use.


Image by USGSRead or download Scientific Investigations Report 2006-5001 at the USGS Website.

Labels: Ground-Water

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The Earth Institute at Columbia University has published an interesting study that relates sea level rise to population density and economics. Their study focused on low elevation coastal zones (LECZ) - areas that are less than 10 meters above sea level. Their more interesting findings include:

• approximately 10% of world population lives within LECZ
• some of the least developed countries have a very high percentage of their populations living within LECZ
• approximately 13% of world urban population lives within LECZ

. The information provided in this study should be of increasing interest as world awareness of tsunami, hurricane and other coastal hazards increases.

A more detailed summary and link to the full report can be found at the Earth Institute Website.

Labels: Global-Warming

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Apophis, a 1000 foot wide asteroid will cross Earth's orbit on Sunday, April 13, 2036. Scientists estimate that it has one chance in about 6,250 of hitting the earth. Such an impact would yield one of the greatest natural disasters in human history. The impact would create a blast that is thousands of times more powerful than the largest atomic weapon. This would kill millions of people if the impact occurred near a populated area or create an enormous tsunami if the impact happend in the ocean.

Read more about the Apophis Asteroid at Topix.net.

Labels: Meteor-Meteorite

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On May 3rd, a 7.9-magnitude earthquake near Tonga prompted tsunami warnings in New Zealand, American Samoa, and Fiji. Fortunately there were only minor injuries and damage from the earthquake and the 2 foot high tsunami that it generated.

Seismic waves produced by the earthquake traveled through the earth at about 7400 miles per hour and arrived at a water well near Christiansburg, Virginia (7200 miles away) in a little under an hour. These waves compressed and expanded fractures that intersect a USGS ground water monitoring well and caused the well to surge up and down for nearly an hour. The surging of less than six total inches can be seen on the hydrograph below.

This well has a history of teleseismic activity. In 1985 it surged about 7 feet in response to the magnitude 8 earthquake near Mexico City and surged again after the magnitude 9 Indonesia earthquake of December, 1994.


Image by USGSVisit the Water Level Monitoring Station for this well.

Labels: Earthquakes

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Interesting legal battles have arisen over the ownership of "Sue", the T-Rex dinosaur that is on display in the Chicago Field Museum. Commercial fossil hunters found it and paid a landowner to excavate it from land that is an inholding within a Sioux Reservation. The fossil hunters, land owner, tribe and United States government all claimed ownership of this fossil that is worth over $8,000,000.

Read more at the Concurring Opinions website.

Labels: Fossils

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The Hubble Space Telescope has captured views showing the break-up of Comet 73P/Schwassmann-Wachmann 3. The comet is breaking up in response to the thermal, gravitational and dynamical stresses of approaching the sun.


Image by NASA

Read and see more images of the Comet Break-up at the Hubble Website.

Labels: Astronomy-Planets

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