Earth science (also known as geoscience, the geosciences or the Earth Sciences), is an all-embracing term for the sciences related to the planet Earth. It is arguably a special case in planetary science, being the only known life-bearing planet. There are both reductionist and holistic approaches to Earth science. The major historic disciplines use physics, geography, mathematics, chemistry, and biology to build a quantitative understanding of the principal areas or spheres of the Earth system.

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Earth's spheres

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• Geology describes the rocky parts of the Earth's crust (or lithosphere) and its historic development. Major subdisciplines are mineralogy and petrology, geochemistry, geomorphology, paleontology, stratigraphy and sedimentology.

• Geodesy and Geophysics (joined together in the IUGG) investigate the figure of the Earth, its reaction to forces and its potential fields (magnetic and gravity field). Geophysicists explore also the Earth's core and mantle and the natural deposits, Geodesists the movement of stars and satellites.

• Soil science covers the outermost layer of the Earth's crust that is subject to soil formation processes (or pedosphere). Major subdisciplines include edaphology and pedology.

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USGS Newsroom

From Toxic Dust and Algae to Ill Winds From Africa
OC_Web@usgs.gov (Office of Communications Web Group) Fri, 20 Nov 2009 10:02:25 -0400
USGS at the Society of Environmental Toxicology and Chemistry Note to editors: The SETAC conference will be held in New Orleans from Nov. 19-23. For more info on the conference, visit their Web site. Toxic dust: Toxins in coal-tar-based sealcoats in parking lots may be the culprit in contaminated house dust, according to a USGS study. PAHs – or polycyclic aromatic hydrocarbons – are large molecules found in oil, coal and tar deposits, and can have toxic effects. It’s long been known that PAHs are often found in house dust; however, the specific sources of these PAHs are largely undetermined. Researchers found that dust from indoor areas near parking lots with coal-tar-based sealcoat had substantially elevated concentrations of PAHs. This study, PAHs in house dust and relation to coal-tar-based pavement sealcoat, will be presented on Nov. 20 at 10:20 a.m. in the Belle Chasse Room. For more information, contact Barbara Mahler at bjmahler@usgs.gov or at 512-927-3566. Eensy-weensy spiders play large role as sentinels of contaminants: Spiders that live near water may be an effective warning system for contaminants in aquatic ecosystems, according to a new USGS and U.S. Environmental Protection Agency study. Scientists examined PCB (polychlorinated biphenyls) levels in shoreline-living spiders at Lake Hartwell, a Superfund site in South Carolina, and used this information to map contaminant concentrations in lake sediment. Future monitoring studies will use the spiders as indicators of ecosystem recovery from PCB contamination. Researchers also made risk maps for a spider-eating bird, the Carolina wren, which could be exposed to PCBs through eating spiders. These spiders rely heavily on adult aquatic insects for food and play a key ecological role in the transfer of contaminants between water and land ecosystems. In spite of this, they are underused as a sentinel species at contaminated sediment sites. This study, using riparian spiders as sentinels of PCB export and risk, will be presented on Nov. 21 at 3:50 p.m. in the Versailles Room. To learn more, contact David Walters at waltersd@usgs.gov or at 970-226-9484. It’s an ill wind that blows: African dust making it across the ocean: Increasing quantities of African dust have blown across the Atlantic Ocean to the Caribbean and Americas over the past few decades. During that time, the dust’s composition has changed. In this study, African dust air masses in Africa and the Caribbean were analyzed for persistent organic contaminants and metals.  These potentially toxic contaminants can originate from the burning of plastics, biomass and waste; widespread use of pesticides, plastics, and pharmaceuticals; and increased industrialization. Multiple pesticides and other contaminants, including carcinogens, suppressors of immune systems, disruptors of endocrine systems, and nervous system or liver toxins were identified from all sample sites.  All are known to persist in the environment, accumulate in organisms, and are toxic at very low concentrations. This study, Chasing clouds of dust: transoceanic transport of synthetic organic pollutants and trace metals with African dust, will be presented on Nov. 22 at 11 a.m. in Ballroom D. For more information, contact Ginger Garrison at ginger_garrison@usgs.gov or at 727-803-8747, ext. 3061. Invasive carp and the secret language of scent: The chemical language of invasive Asian carp may eventually be turned against them in the fight to help eradicate these harmful invaders from the Mississippi River.  Asian carp, introduced into the Mississippi River in the 1970s and 80s, are now abundant throughout the lower Missouri, the Mississippi and Ohio rivers, posing a threat to native species. Carp seem to have a chemical language effective for predator defense and reproduction in murky environments, so researchers put this language to the test by subjecting young carp to extracts prepared from the skins of other carp. The result: the young carp, upon detecting the extracts, significantly avoided them by moving from the area, becoming immobile, and schooling. This “alarm substance” may be effective in repelling carp from habitat critical to native species. Young carp were also attracted to the chemical stimuli of schooling carp, which can assist in conventional eradication methods.  This study, Use of pheromones to control invasive Asian carp, will be presented on Nov. 20t at 10:40 a.m. in the Elmwood Room. To learn more, contact Robin Calfee at rcalfee@usgs.gov or at 573-441-2969. Toxic algae may be harming endangered suckers in Klamath Lake:  Preliminary data suggest that algal toxins may be hindering the population growth of endangered Lost River suckers and shortnose suckers in Upper Klamath Lake in southern Oregon. This lake is characterized by high levels of nitrogen and phosphorus, nutrients that promote large, frequent cycles of cyanobacterial or algal blooms from spring through fall. Researchers evaluated the presence and effects of these toxins, specifically microcystins, which are harmful to other aquatic life, in the lake’s water and in fish from the lake. Examination of liver tissues from juvenile suckers revealed adverse physiological effects consistent with tissue damage associated with microcystin exposure. Significant concentrations of the toxins were reported form all field sampling stations in the lake.  This study, Cyanobacterial toxins found in Upper Klamath Lake, Oregon: implications for endangered fish, will be presented on Nov. 22 at 1:10 p.m. in Ballroom C. To learn more, contact Kathy Echols at kechols@usgs.gov or at 573-876-1838. Wading through the sources of lake contamination: Contamination of urban lakes and streams by polycyclic aromatic hydrocarbons (PAHs) is widespread and has been increasing over the last 40 years in the United States. These PAHs can be toxic to bottom-dwelling organisms, can cause tumors in fish, and several are believed to cause cancer in humans.  In this study, researchers examined five sources of PAHs in 40 urban lakes from across the United States, including coal-tar-based pavement sealcoat, coal combustion, oil combustion, vehicle emissions and wood combustion. Of the five sources studied, sealcoat was the strongest contributor to PAH contamination in lake sediment. This research can help those trying to reduce pollution levels in the urban environment by providing them with a better understanding of PAH sources.  This study, Sources of PAHs to urban lakes in the United States, will be presented on Nov. 23 at 11:20 a.m. in the Jefferson Room. For more information, contact Peter Van Metre at pcvanmet@usgs.gov or at 512-927-3506. Tiny particles with big effects: Industrially produced nanoparticles are being dispersed into the environment from a range of everyday human activities. Use of consumer nanoproducts, such as sunscreen with zinc oxide or bed sheets and socks containing silver nanoparticles, all have the potential to release metals into the environment. Some of these particles can be toxic, but little is known about how nanoparticles will accumulate in the environment. Interactions between nanoparticles and living organisms are influenced by the unique physico-chemical properties of each kind of nanoparticle. This study introduces a new approach to evaluate the toxicity of nanoparticles with metal as an ingredient, and offers a way to begin to understand potential beneficial uses and potential environmental risks. This study, Characterizing the bioavailability and toxicity of engineered nanoparticles using enriched isotope tracers and biodynamic modeling, will be presented on Nov. 22 at 10 a.m. in the Oak Alley Room. For more information, contact Marie-Noele Croteau at mcroteau@usgs.gov or at 650-329-4424. Cause of feminized male sturgeon remains elusive: The number of male shovelnose sturgeon with female characteristics in the Missouri River has increased from about 3 percent in 1968 to 15 percent in 2001. USGS researchers examined the levels of PCBs (polychlorinated biphenyls) and organochlorine pesticides in normal and intersex fish to see whether these hormone-mimicking compounds were associated with the condition. Although the compounds were all present in sturgeon at levels of concern, no differences in levels between intersex male fish and normal male fish were detected. Still, reproductive development is complex and can depend on many factors, including a fish’s age at its first exposure.  These fish are also exposed to many other compounds that have not yet been tested. Recent findings of intersex in endangered pallid sturgeon underscore the need to find the cause of this condition. This study, Intersex gonads in Missouri River shovelnose sturgeon: occurrence, severity, and association with contaminants, will be presented on Nov. 22 at 8:40 a.m. in Ballroom A. To learn more, contact Diane Papoulias at dpapoulias@usgs.gov or at 573-999-1788.
Waves of Survival in American Samoa
OC_Web@usgs.gov (Office of Communications Web Group) Wed, 18 Nov 2009 13:06:46 -0400
Pete Gurr, a resident of American Samoa, was on his way to work when he felt an earthquake that originated 110 miles out at sea. Because of tsunami training he had received, he knew about the possibility of a deadly wave and drove down to the closest coastal village, where he warned the residents. Similarly, Tina Pule knew the earthquake was stronger than usual and told her parents to go inland. Related Podcasts Tsunami Research Keeping People Safe Download directly | Details   or subscribe by e-mail. Although they had just 10 to 15 minutes between the end of the shaking and the arrival of the first deadly wave to shore, many other American Samoa locals have similar stories of survival that USGS researchers heard when they arrived on the island to collect data immediately following the tsunami. “Thanks to education efforts, thousands of locals had the knowledge to get to higher ground as soon as they felt shaking,” said Bruce Jaffe, a USGS oceanographer, who traveled to American Samoa with a rapid response team of tsunami scientists. “This research on water levels and sediment deposits immediately following a tsunami is an essential part of future education efforts because it is used to improve tsunami models — these are vital for designing evacuation routes, building stronger structures and determining the best areas for building.” The USGS team also collected information to help interpret the geologic record to determine how frequently tsunamis of this magnitude are likely to strike American Samoa. Scientists can determine this frequency by examining sediment, because each tsunami that hits the area leaves a distinct, new sand layer or boulder deposit. “We don’t know how often similarly large tsunamis strike American Samoa and whether larger tsunamis have hit the island in the past,” said Jaffe. “There are advantages to living on the coast, so people may live with the risk if it’s not likely that a tsunami this destructive will strike for a long period of time. This research helps us determine that risk.” If the scientists had waited any longer than a week after the tsunami to collect this information, much of it would have been lost forever to clean-up efforts and natural processes. Just days after the tsunami, people were already scrubbing water marks from homes and removing debris, two of the best sources for determining where and how high the water flowed. By continuing research on this tsunami, the USGS is working to improve the ability to interpret tsunami characteristics from the resulting deposits, determine the role coral reefs play in protecting the shore, and document and model how reef channels affect the tsunamis. In addition to tsunami research, the USGS also sent a field party to deploy portable seismometers in American Samoa to detect aftershocks and collect valuable data for determining how ground motions vary in different parts of the island. This is a key parameter for making a seismic hazard assessment for American Samoa. “Although we have come a long way in studying tsunamis in the last two decades, we must continue to focus on this kind of research because tsunamis are still poorly understood,” said USGS tsunami scientist Guy Gelfenbaum, who also traveled to American Samoa following the tsunami. “Having a better understanding of how a tsunami’s height and speed change as it moves onshore through this research will contribute to keeping people safe.” Interviews with survivors, pictures of the damage, and maps of water heights used to make tsunami models can be found in “notes from the field” from this USGS team. The USGS team will continue to update this page as new information comes in. Listen to episode 110 of the USGS CoreCast for an interview with Bruce Jaffe, and check out the USGS Multimedia Gallery for high resolution photos of the effects of this tsunami. [Access images for this release at: <a href="http://gallery.usgs.gov/tags/CoreCast110" mce_href="http://gallery.usgs.gov/tags/CoreCast110">http://gallery.usgs.gov/tags/CoreCast110</a>]  
Free U.S. Earth Imagery Sharpens Shared View of Global Challenges
OC_Web@usgs.gov (Office of Communications Web Group) Mon, 16 Nov 2009 16:55:02 -0400
USGS Director McNutt a Leader in U.S. Delegation at International Conference Free, easily accessible U.S. satellite data enables any citizen, scientist, or analyst who can use the information to contribute to a shared vision of the challenges facing our planet. That's the message the newly-appointed director of the U.S. Geological Survey, Dr. Marcia McNutt, plans to deliver when representatives of 80 governments and over 50 participating organizations convene at the international Group on Earth Observations (GEO-VI) meeting, November 16-17, in Washington, D.C. “Our policy of providing free Landsat data supports a central GEO goal: to promote global distribution of earth observation data,” said McNutt. "With a continuous record of earth observation since 1972, Landsat provides the most complete set of land surface information as well as a vital historical perspective for researchers, decision makers, and commercial users around the world.” From over 400 miles above Earth, the scale of Landsat imagery makes it particularly useful in understanding natural and human-induced changes to the planet. The data enable a wide array of investigations — from supporting disaster relief efforts to making agricultural crop assessments to correlating environmental conditions with famine, biodiversity, and human health. Beginning with the launch of Landsat 1 in 1972, Landsat, a joint operation of USGS and NASA, has produced over two million space-based, moderate-resolution, land remote sensing images. The massive data archive is maintained at the USGS-EROS facility in Sioux Falls, S.D.  “As the world’s increasing population is compelled to face the effects of climate change and the limitations of water, petroleum, and other vital resources, the broad availability of images from Landsat and other earth observation satellites benefits both developing and developed countries,” said Dr. McNutt. McNutt became the 15th USGS Director on November 5.  USGEO, the American contribution to GEO, is sponsored by 15 federal agencies and two White House offices. “I am very pleased to note that it was the agency I now direct, USGS, that opened the Landsat archive to the world free of charge,” McNutt continued. “Since the archive was opened, over 1 million images have been provided to users from 180 countries — a resounding success.” For further information, visit: Group on Earth Observations (GEO) GEO-VI: Sixth Plenary Session of the Group on Earth Observations USGS Landsat  
Pesticide Levels Decline in Corn Belt Rivers
OC_Web@usgs.gov (Office of Communications Web Group) Mon, 09 Nov 2009 11:00:00 -0400
Concentrations of several major pesticides mostly declined or stayed the same in “Corn Belt” rivers and streams from 1996 to 2006, according to a new U.S. Geological Survey study. The declines in pesticide concentrations closely followed declines in their annual applications, indicating that reducing pesticide use is an effective and reliable strategy for reducing pesticide contamination in streams. Declines in concentrations of the agricultural herbicides cyanazine, alachlor and metolachlor show the effectiveness of U.S. Environmental Protection Agency (EPA) regulatory actions as well as the influence of new pesticide products. In addition, declines from 2000 to 2006 in concentrations of the insecticide diazinon correspond to the EPA’s national phase-out of nonagricultural uses. The USGS works closely with the EPA, which uses USGS findings on pesticide trends to track the effectiveness of changes in pesticide regulations and use. Scientists studied 11 herbicides and insecticides frequently detected in the Corn Belt region, which generally includes Illinois, Indiana, Iowa, Nebraska and Ohio, as well as parts of adjoining states. This area has among the highest pesticide use in the nation — mostly herbicides used for weed control in corn and soybeans. As a result, these pesticides are widespread in the region’s streams and rivers, largely resulting from runoff from cropland and urban areas. Elevated concentrations can affect aquatic organisms in streams as well as the quality of drinking water in some high-use areas where surface water is used for municipal supply. Four of the 11 pesticides evaluated for trends were among those most often found in previous USGS studies to occur at levels of potential concern for healthy aquatic life. Atrazine, the most frequently detected, is also regulated in drinking water. “Pesticide use is constantly changing in response to such factors as regulations, market forces, and advances in science,” said Dan Sullivan, lead scientist for the study. “For example, acetochlor was registered by the EPA in 1994 with a goal of reducing use of alachlor and other major corn herbicides — acetochlor use rapidly increased to a constant level by about 1996, and alachlor use declined. Cyanazine use also decreased rapidly from 1992 to 2000, as it was phased out because of environmental concerns. Metolachlor use did not markedly decrease until about 1998, when S-metolachlor, a more effective version that requires lower application rates, was introduced. Each of these declines in use was accompanied by similar declines in concentrations.” Although trends in concentration and use almost always closely corresponded, concentrations of atrazine and metolachlor each declined in one stream more rapidly than their estimated use. According to Skip Vecchia, senior author of the report on this analysis, “The steeper decline in these instances may be caused by agricultural management practices that have reduced pesticide transport, but data on management practices are not adequate to definitively answer the question. Overall, use is the most dominant factor driving changes in concentrations.” Only one pesticide — simazine, which is used for both agricultural and urban weed control — increased from 1996 to 2006. Concentrations of simazine in some streams increased more sharply than its trend in agricultural use, suggesting that non-agricultural uses of this herbicide, such as for controlling weeds in residential areas and along roadsides, increased during the study period. The USGS study is based on analysis of 11 pesticides for 31 stream sites in the Corn Belt for two partially overlapping time periods: 1996 to 2002 and 2000 to 2006. Pesticides included in the trend analyses were the herbicides atrazine, acetochlor, metolachlor, alachlor, cyanazine, EPTC, simazine, metribuzin and prometon, and the insecticides chlorpyrifos and diazinon. Additional detailed analyses of relations between concentrations and use focused on four herbicides mainly used for weed control in corn (atrazine, acetochlor, metolachlor and alachlor) at a subset of 11 sites on the main rivers and selected large tributaries in the Ohio, Upper Mississippi and Missouri River basins. Concentrations of many other pesticides that were less prevalent than the 11 included in the study were below analytical detection limits in most samples and thus could not be analyzed for trends. Glyphosate, an Subscribe to Earth_Sciences RSS feed

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