Broad term for all science related to the study of the earth.
Annual hydrologic data report of Pennsylvania [ More info] Online annual reports (since 1999) documenting hydrologic data for Pennsylvania gathered from USGS surface water and ground water data-collection networks and information on ordering paper copies of previous years.
ANSS - Advanced National Seismic System [ More info] Nationa network of seismic monitoring stations coordinated with a variety of regional organizations and academic institutions.
Antimony: a flame fighter [ More info] Explains how we use this element, where it is found, and describes the worldwide supply and demand for this commodity.
Application of the SPARROW watershed model to describe nutrient sources and transport in the Missouri River Basin [ More info] Maps and diagrams showing how the mathematical model predicts the distribution of various pollutants within a large watershed.
Aquifer basics [ More info] Links to general information on water supply by aquifers based on rock types and to principal national aquifers by name.
Arctic National Wildlife Refuge, 1002 Area, petroleum assessment, 1998, including economic analysis [ More info] Arctic National Wildlife Refuge (ANWR) 1002 area's petroleum resource assessment. Text available in PDF and HTML formats.
Asbestos: geology, mineralogy, mining, and uses [ More info] Report on asbestos, six types of mineral fibers belonging to two mineral groups, serpentines and amphiboles,with fiber morphology, crystal structure, analytical methods, properties, mining, milling, uses, and safety factors.(PDF file,28 pp.,4.5 MB)
Ask-A-Geologist [ More info] Site to submit a question to Ask-A-Geologist where scientists research the answers to the questions, then reply directly by email.
Assessing Groundwater Availability in the High Plains Aquifer in Parts of Colorado, Kansas, Nebraska, New Mexico, Oklahoma, South Dakota, Texas, and Wyoming [ More info] Explains concepts and methods used to determine the likely future supply of usable water in this major aquifer.
Assessing groundwater availability in the North Atlantic Coastal Plain aquifer system [ More info] Nature, history, and distinctive characteristics of this aquifer system help us to understand the likely distribution of available groundwater.
Alphabetical Index of Topics
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