December 2008 on EARTH Magazine

Mineral Resource of the Month: Iron Oxide Pigments

Wed, 20 Jun 2018 17:32:29 -0400

Michael J. Potter, mineral commodity specialist for the U.S. Geological Survey, has compiled the following information on iron oxide pigments.

Iron oxides were deposited from water that trickled down a cliff face in an Arizona canyon. Credit: © Larry Fellows, Arizona Geological Survey, ESW Image Bank

Iron oxide pigments, which may be natural or synthetic, have been used as colorants since early humans began painting on cave walls. Natural pigments are derived from several iron oxide minerals: Red pigments are derived from hematite. Yellow and brown pigments — ochres, sierras and umbers — are derived from limonite. Magnetite provides a black iron oxide pigment. Micaceous iron oxide is a special form of hematite that occurs in thin metallic gray platelets or flakes. Synthetic pigments are manufactured under controlled conditions such that particle size, distribution and shape can be accurately replicated, resulting in superior uniformity, color quality and chemical purity.

Energy Notes: August 2007-2008

Wed, 20 Jun 2018 17:32:08 -0400

Credit: The American Geosciences Institute

U.S. Oil & Petroleum Imports (millions of barrels per day)

Oil and petroleum imports data are preliminary numbers taken from the American Petroleum Institute’s Monthly Statistical Report. For more information visit www.api.org.

Down to Earth With: Maurice J. 'Ric' Terman

Wed, 23 May 2018 17:22:13 -0400

Maurice Terman. Credit: Courtesy of Maurice Terman

A general wants to advance his army of tanks, but doesn’t know if the terrain he plans to cross will allow it. Tanks can’t go up steep slopes, for instance. And they can’t knock down large trees or traverse soft ground like peat bogs. That’s where military geologists come in — earth scientists who scope out the terrain to determine its suitability for different types of movement and construction.

AGU: Aloha, magma! Geothermal engineers drill into surprising lava

Thu, 05 Jan 2012 06:41:58 -0500

Aerial view of channelized lava flow from Pu'u O'o in 1983. Photo is by J.D. Griggs, courtesy of U.S. Geological Survey

The location of Kilauea's Pu'u O'o crater activity in 2001. NASA Landsat

SAN FRANCISCO — While drilling deep into Earth, geothermal engineers struck geological gold, opening a never-before-seen window into a classic geologic process: how basalt magma becomes granite. The find, they announced at the annual meeting of the American Geophysical Union on Tuesday, could amount to the first magma observatory on Earth.

AGU: Climate science report questions likelihood of abrupt climate change

Thu, 05 Jan 2012 06:41:58 -0500

SAN FRANCISCO — A new U.S. Climate Change Science Program report states that abrupt climate change is unlikely to happen over the next century, scientists announced Tuesday at the annual meeting of the American Geophysical Union. However, the longer-term impacts of climate change could still be severe.

AGU: Colorado ski industry owes Great Salt Lake thank you note

Thu, 05 Jan 2012 06:41:58 -0500

Utah's Great Salt Lake, as seen from the International Space Station in August 2003. The north and south sections of the lake are separated by a railway and have different salt concentrations. NASA Earth Observatory

SAN FRANCISCO — Colorado skiers have long suspected that snowfall is fluffiest when winds blow salt and dust eastward from the Great Salt Lake in Utah. Now that wisdom is confirmed by science.

AGU: How scientists should talk climate change

Thu, 05 Jan 2012 06:41:58 -0500

Blogging on EARTH

SAN FRANCISCO — The Intergovernmental Panel on Climate Change's Fourth Assessment report last year showed a strong consensus among scientists that the climate is warming, thanks largely to anthropogenic greenhouse gases. So one has to wonder why scientists are still struggling to get that message through to both policymakers and stakeholders.

AGU: Mount St. Helens has gone back to sleep

Thu, 05 Jan 2012 06:41:58 -0500

Aerial view of Mount St. Helens' crater, as seen from the north on May 30, 2008. Scientists say the eruption that has been ongoing since October 2004 ended early this year. Steve Schilling, USGS

Seismometers recorded a spike in earthquake activity when the volcano first renewed its eruption in October 2004. Seismic activity has since waned. John Clemens, USGS

USGS scientist Michael Poland collects information from a GPS station on the east flank of Mount St. Helens. Many GPS stations have been installed on or around the volcano to measure ground deformation. Dan Dzurisin, USGS

Researchers dropped "spiders" onto Mount St. Helens' growing lava dome to track the eruption in locations too dangerous for humans to go. Dan Dzurisin, USGS

One way researchers gather data on volcanic gas emissions is through devices like this on the helicopter step, which collects data as researchers fly over the volcano. Ken McGee, USGS

The decapitated Mount St. Helens in 1983, three years after the devastating 1980 eruption that killed 57 people. The gigantic debris avalanche that removed the former summit swept through Spirit Lake, spawning a 250-meter tsunami. USGS Cascades Volcano Observatory

SAN FRANCISCO — After more than three and a half years of continuous eruption, Mount St. Helens in Washington quieted earlier this year. Following intense monitoring efforts, the volcano is officially “asleep,” researchers reported Thursday at the annual meeting of the American Geophysical Union.

Benchmarks: December 3, 1984: Bhopal gas leak kills thousands

Thu, 05 Jan 2012 06:41:58 -0500

On Dec. 3, 1984, Aziza Sultan woke to the sound of coughing. When she opened her eyes, she could see that the room was filled with a white haze. She heard people shouting “Run, run.” Then she too began to cough. Each breath burned her lungs.

EIA: Worldwide oil demand will plummet in 2009

Thu, 05 Jan 2012 06:41:58 -0500

Standard Oil 'blue barrel' U.S. Department of Energy

Blogging on EARTH

The Department of Energy’s Energy Information Administration is projecting that the global demand for oil will plummet even faster next year than it did this year — largely because of lower forecasts for global economic growth.

Minerals also evolve

Thu, 05 Jan 2012 06:41:58 -0500

Callan Bentley

Taxonomy, the science of classification, connects creatures through genealogical relationships. But taxonomist Carl Linné (Linnaeus) didn't stop with living organisms; he applied his system to all natural objects — even minerals. And according to a new study, he may have been on to something: Iron may not pass genes to its rusted cousin iron oxide, but like living organisms, minerals have evolved considerably over the course of Earth’s history.

Swarm of earthquakes rattles Yellowstone

Thu, 05 Jan 2012 06:41:58 -0500

Yellowstone's Excelsior Geyser, in the Midway & Lower Geyser Basin, erupts in July 2001. Jim Peaco, courtesy of the National Park Service

Yellowstone Falls, Wyoming USGS Photo by David E. Wieprecht

An abnormally high number of earthquakes has shaken up Yellowstone National Park in the past week. Since Friday, a “swarm” of more than 250 low-magnitude, shallow quakes has repeatedly rattled an area under Yellowstone Lake, with the highest-magnitude tremor — a magnitude-3.9 quake — on Saturday. The seismic activity has raised fears that the quakes may foreshadow a larger earthquake, or a volcanic eruption — but scientists say there isn’t yet reason to fear an eruption.

Travels in Geology: Australia's wonders, from ocean to desert

Thu, 05 Jan 2012 06:41:58 -0500

Ayers Rock at sunset. Why the world's largest monolith is in an otherwise flat terrain is a geological mystery. Jason Betzner

The Blue Mountains glow in the mid-morning sunlight. Jason Betzner

The Three Sisters are composed of sandstone carved by wind and rain. The Aborigines believe the Three Sisters were women turned to stone by a magician. Jason Betzner

A cable car carries tourists in the Blue Mountains across a valley thousands of meters below. Jason Betzner

In the dead center of Australia, Ayers Rock rises above the bush. Sunset brings an orange, red and purple glow to its walls. Jason Betzner

Ayers Rock displays many odd weathering patterns, such as honeycomb weathering. Although common in coastal and semi-arid environments, its cause is still disputed by geologists. Jason Betzner

Baffling weathering patterns on Ayers Rock: The large scour shape suggests the rock was powerfully carved by water. The alignment of the boulders in such an organized pattern is particularly strange. Jason Betzner

Aboriginal paintings on Ayers Rock. Jason Betzner

Cairns, on the Northeastern coast of Australia, is the gateway to the Great Barrier Reef. The reef (dark patch) is just visible in the shallow water. Jason Betzner

A parrot fish (blue) and an angel fish (black) hover over soft corals. The parrot fish use their hard "beak" to gnaw at the coral, which is their primary food source. (You can actually hear the gnawing while snorkeling.) Jason Betzner

Colorful soft corals (top half) are surrounded by bleached, dead corals (bottom half). Jason Betzner

Zebra fish and two different types of groupers on the Great Barrier Reef. Jason Betzner

A very friendly grouper on the Great Barrier Reef. Jason Betzner

Australia, both a country and a continent, has geological wonders as strange and unique as the furry marsupials that inhabit the Land Down Under.