Geology

Nearly forgotten research from decades ago complicates the task of quantifying earthquake hazards in the Pacific Northwest, according to a new report.

The report focuses on the Cascadia subduction zone—a giant active fault that slants eastward beneath the Pacific coast of southern British Columbia, Washington, Oregon, and northern California.

Geologic studies in the past three decades have provided increasingly specific estimates of Cascadia earthquake sizes and repeat times. The estimates affect public safety through seismic provisions in building design and tsunami limits on evacuation maps.

Tokyo is a city of more than 13 million people and they are no strangers to earthquakes. The city, like much of Japan, has been devastated by earthquakes in the past and likely will be again - but when?

Ongoing slow-slip earthquakes can't usually be felt at the surface but they play a role in relieving or building up geological stress and recent research examining plate movements under Tokyo has found that, since the massive magnitude-9 Tohoku earthquake and tsunami in March 2011, recurrence intervals for non-damaging slow-slip quakes beneath Japan's capital have shortened. 

This has led some seismologists to wonder if this aseismic creep could be signaling a countdown to Tokyo's next "big one."


A long lasting foreshock series controlled the rupture process of this year's great earthquake near Iquique in northern Chile, according to an international research team

The earthquake was heralded by a three quarter year long foreshock series of ever increasing magnitudes culminating in a Mw 6.7 event two weeks before the mainshock.

The mainshock (magnitude 8.2) finally broke, on April 1st, a central piece out of the most important seismic gap along the South American subduction zone. The study reveals that the Iquique earthquake occurred in a region where the two colliding tectonic plates where only partly locked.


The biggest mystery in the mid-east is why countries of one religion won't put the country of another religion on any geographical maps in any of its schools, but the second biggest mystery is why many of the oldest parts of Jerusalem's Western Wall look like they could have been placed yesterday.

The Western Wall is a remnant of the ancient wall that surrounded the courtyard of the Jewish Temple in Jerusalem. It is located in Jerusalem's Old City at the foot of the Temple Mount.


Hydraulic fracturing is in the news because more natural gas has meant substantially fewer carbon emissions - and it has also been implicated in a variety of environmental issues.

Man is doing what nature has always done, albeit on a different time scale. A new GSA BULLETIN study  examines how long it takes natural Earth processes to form hydraulic fractures and whether the formation is driven by sediment compaction, oil and gas generation or something else. Plus, in order to make environmental models about modern hydraulic fracturing production, it's important to know what role these natural fractures play.


A new study has found that more than 75 percent of the water loss in the drought-stricken Colorado River Basin since late 2004 came from underground resources., which means the extent of groundwater loss may pose a greater threat to the water supply of the western United States than previously thought.

This study is the first to quantify the amount that groundwater contributes to the water needs of western states. According to the U.S. Bureau of Reclamation, the federal water management agency, the basin has been suffering from prolonged, severe drought since 2000 and has experienced the driest 14-year period in the last hundred years.


A new study suggests that Saharan dust played a major role in the formation of the Bahamas islands. Researchers from the University of Miami (UM) Rosenstiel School of Marine and Atmospheric Science showed that iron-rich Saharan dust provides the nutrients necessary for specialized bacteria to produce the island chain's carbonate-based foundation.


In Jeju, a place emerging as a world-famous vacation spot with natural tourism resources, a recent study revealed a volcanic eruption occurred on the island. The Korea Institute of Geoscience and Mineral Resources (KIGAM) indicated that there are the traces that indicated that a recent volcanic eruption was evident 5,000 years ago.

That is the first time to actually find out the date when lava spewed out of a volcano 5,000 years ago in the inland part of the island as well as the one the whole peninsula.


A new global geologic map of Mars is the most thorough representation of the "Red Planet's" surface, bringing together observations and scientific findings from four orbiting spacecraft that have been acquiring data for more than 16 years.

The Appalachian mountain chain runs along a nearly straight line from Alabama to Newfoundland— 1,500 miles - except for a curious bend in Pennsylvania and New York.

Why it bends has been a mystery. When the North American and African continental plates collided more than 300 million years ago, the North American plate began folding and thrusting upwards as it was pushed westward into the dense underground rock structure—in what is now the northeastern United States. The dense rock created a barricade, forcing the Appalachian mountain range to spring up.  Yet the bend was cause for speculation.