Category: General Geology

Article by: Hobart M. King, Ph.D., RPG Old Faithful geyser of Yellowstone National Park blasts water about 150 feet into the air. copyright iStockphoto / Zuki. What is a Geyser? A geyser is a vent in Earth's surface that periodically ejects a column of hot water and steam. Even a small geyser is an amazing phenomenon; however, some geysers have eruptions that blast thousands of gallons of boiling-hot water up to a few hundred feet in the air.

Article by Sara Bennett, geology instructor at Western Illinois University. Bucher Valley Glacier in Alaska beautifully represents a large glacier that receives ice from multiple smaller glaciers that join it like the tributaries of a stream. Image by the United States Geological Survey. What is a Glacier?

North America's bear areas map: This map shows the overlapping geographic ranges of three types of bears that inhabit North America - polar bears, black bears, and grizzly bears (also known as brown bears). This map was compiled by superimposing three maps prepared by Karl Musser (American black bear - Creative Commons License), Simon Pierre Barrette (grizzly bear - GNU Free Document License), and Fabio B (polar bear - public domain).

How to Avoid Them and What to Do if Attacked A grizzly bear walking along the edge of a stream. Stream banks are a common place to encounter bears. Image copyright iStockphoto / IndrekV. North American bear map: This map shows the overlapping geographic ranges of three types of bears that inhabit North America - polar bears, black bears and grizzly bears (also known as brown bears).

Article by: Hobart M. King, Ph.D., RPG Stream discharge hydrograph. Enlarge graph. Hydrographs are charts that display the change of a hydrologic variable over time. Here are several examples from the US Geological Survey's gaging station on the Tioga River near Mansfield, Pennsylvania. Although these examples are from a stream, hydrographs can also be made for lakes, water wells, springs and other bodies of water.

Major Chronostratigraphic and Geochronologic Units Republished from a July 2010 Fact Sheet by the United States Geological Survey. Geologic Time Scale: Divisions of Geologic Time approved by the U.S. Geological Survey Geologic Names Committee, 2010. The chart shows major chronostratigraphic and geochronologic units.

Stream Discharge Monitoring Gaging stations are facilities used by hydrologists to automatically monitor streams, wells, lakes, canals, reservoirs, or other water bodies. Instruments at these stations collect information such as water height, discharge, water chemistry, and water temperature. These stations collect information about the stream and transmit it to the USGS via a satellite communication system.

Written by Wayne Ranney, author of Carving Grand Canyon: Evidence, Theories and Mystery . Introduction The Grand Canyon is one of the most recognizable landforms on planet Earth and the most often asked question about it is, "When did it form?" If only there were a simple answer! Geologists still debate many of the details about the origin and age of the canyon but recent geologic research has shed new light on the topic.

The life of a snowflake begins high in Earth's atmosphere, and if the snowflake is very lucky it might reach the ground. Article by: Hobart M. King, Ph.D., RPG Snowflakes have unique shapes: Photographs of many snowflakes showing how each has a hexagonal crystalline structure but a unique geometry. The shapes of the flakes are determined by the atmospheric conditions experienced as it fell through the sky.

Some bottled water products are geological. Mineral, artesian, spring, sparkling, and groundwater are from natural sources. But much of the bottled water sold today is straight from a tap. Article by: Hobart M. King, Ph.D., RPG Vintage Water Bottles: Early bottled waters were sold in fancy, colorful, glass bottles.

Masses of salt that erupt onto Earth's surface and flow under their own weight Salt glaciers: Landsat image of two salt glaciers that formed when salt domes erupted from the flanks of mountains in the Zagros fold belt of Iran. The salt glacier on the left is flowing south. The one on the right is flowing north.