http://gallery.usgs.gov/images/logos/usgs_only.jpg http://gallery.usgs.gov/ en-us OC_Web@usgs.gov (Office of Communications Web Group) http://gallery.usgs.gov/images/USGS.gif http://gallery.usgs.gov/ http://gallery.usgs.gov/photos/02_08_2012_t85Bs11RQl_02_08_2012_0 USGS scientists prepare a sampler used to measure emission of polycyclic aromatic carbons (PAHs) into the air.

]]> http://gallery.usgs.gov/photos/02_08_2012_t85Bs11RQl_02_08_2012_1 A professional applicator applies coal-tar-based sealcoat to a test plot used to measure emission of polycyclic aromatic carbons (PAHs) into the air.

]]> http://gallery.usgs.gov/photos/02_08_2012_t85Bs11RQl_02_08_2012_2 A professional applicator applies coal-tar-based sealcoat to a test plot used to measure emission of polycyclic aromatic carbons (PAHs) into the air.

]]> http://gallery.usgs.gov/photos/02_08_2012_t85Bs11RQl_02_08_2012_3 A USGS scientist adjusts an air pump used to measure emission of polycyclic aromatic carbons (PAHs) into the air.

]]> http://gallery.usgs.gov/photos/02_07_2012_uyp0SfeRRM_02_07_2012_0 USGS scientist Peter Van Metre examines a parking lot where coal-tar sealcoat has been applied.

]]> http://gallery.usgs.gov/photos/10_14_2011_i4Dpg66ff0_10_14_2011_4 Suzanne Nicholson, USGS, collecting soil at one of the sites in New Jersey, on the coast of the Atlantic Ocean just south of Atlantic City. The USGS is completing a low-density soil geochemical and mineralogical survey for the conterminous U.S., which is needed as baseline data for environmental investigations and to understand the large-scale processes dominating the distribution of chemical elements at the earth's surface. Current data reveal coherent, continental- to regional-scale patterns that depend on underlying soil parent materials, soil age, land type/land use, and climate. Human-induced modifications to soil geochemistry related to current and historic industrial and agricultural activities are recognized by comparing element concentrations in surface soils to deeper soils at individual sites. However, regional enrichments of some metals of environmental concern resulting from mineralization by natural geologic process can be as high (or even higher) than enrichments from anthropogenic contamination.

]]> http://gallery.usgs.gov/photos/05_10_2011_f30Md55ccw_05_10_2011_2 A large Saharan dust storm leaves the West African coast to move over the Atlantic Ocean and cover downwind islands.  Courtesy Moderate Resolution Imaging Spectroradiometer (MODIS) aboard NASA's Terra satellite on March 2004. 

]]> http://gallery.usgs.gov/photos/08_31_2010_h4COg66fey_08_31_2010_0 This photo shows a snow plow and road salt application truck that is used to clear snow and ice from roadways for improving traffic and pedestrian safety. The use of salt to deice pavement can be harmful to aquatic life in urban streams. The USGS is involved in studies that focus on the influence of winter runoff on aquatic ecosystems.

]]> http://gallery.usgs.gov/photos/08_31_2010_h4COg66fey_08_31_2010_1 This photo shows a road salt storage stockpile that is awaiting use for pavement deicing, Port of Milwaukee, WI. The use of salt to deice pavement can be harmful to aquatic life in urban streams. The USGS is involved in studies that focus on the influence of winter runoff on aquatic ecosystems.

]]> http://gallery.usgs.gov/photos/08_18_2010_o63Vm08LLg_08_18_2010_1 http://gallery.usgs.gov/photos/08_16_2010_typ0Sfe66L_08_16_2010_1 http://gallery.usgs.gov/photos/08_16_2010_typ0Sfe66L_08_16_2010_3 http://gallery.usgs.gov/photos/08_16_2010_typ0Sfe66L_08_16_2010_4 http://gallery.usgs.gov/photos/08_11_2010_qul8Oba44I_08_11_2010_0 http://gallery.usgs.gov/photos/08_11_2010_qul8Oba44I_08_11_2010_1 http://gallery.usgs.gov/photos/05_24_2010_x1Tf83Ivu5_05_24_2010_0 http://gallery.usgs.gov/photos/01_05_2010_cHXj04May7_01_05_2010_0 http://gallery.usgs.gov/photos/155 http://gallery.usgs.gov/photos/156 http://gallery.usgs.gov/photos/157 http://gallery.usgs.gov/photos/158 http://gallery.usgs.gov/photos/159