Recently in Earthquakes Category

Stephen Gao's work on monitoring earthquakes in the Midwest (which we reported on previously) continues to attract attention. The latest media coverage comes from Voice of America, which dispatched a reporter to meet with Gao and his graduate students earlier this summer. The result is this news story: EarthScope Advances Quake Prediction.

Here's an excerpt:

EarthScope is part of a huge project to seismographically map the continental U.S. and Alaska. "The idea is to use 400 seismographs to cover the whole U.S. in about 14 years," Gao explains, adding that the information that will come from those monitors is designed to help scientists predict, not prevent, earthquakes. "[But if] you can predict one, then you can do something to lessen the damage caused by an earthquake," he points out. "People can come out of their house and camp outside. You can shut down the power, the natural gas lines. In that situation, you can reduce the damage a lot."

EarthScope began putting down seismometers on the U.S. west coast in 2002 and is moving its operations eastward across the country. The project is currently entering the area of the New Madrid fault zone, in Missouri and several nearby states. It's the site of one of the most powerful earthquakes ever recorded in North America.

Last month, Science Daily talked to Gao about what days -- and what times of days -- earthquakes are likely to happen. They seem to be more frequent on Sundays or late at night, but Gao says "that's just because it's quiet" during those times.

Over the past five years, an array of 400 seismometers has been slowly moving across the United States, from west to east. The stations are in place for two years, then moved eastward. Now, Missouri S&T researcher Stephen Gao and some students are getting in on the action as the instruments continue their eastward migration.

Gao, a seismologist in Missouri S&T's geology and geophysics program, is working with four students from Missouri universities to conduct field surveys and identify locations for the stations. The effort is part of a National Science Foundation initiative called EarthScope. In 2010-2011, 43 earthquake recording stations will be placed in Missouri and southern Iowa as part of the program.

In addition to recording data on earthquakes, scientists can gather important information about the Earth's inner structure through this program, Gao explains. Seconds after a significant earthquake, geophysicists around the world can access the information recorded by each of the stations to learn more about that part of the Earth.

You can track the current status of the EarthScope seismonomers using this interactive map of the EarthScope website. You'll see that the west is covered with the instruments up until about midway through Nebraska, Kansas, Oklahoma and Texas.

Missouri S&T is hosting an earthquake preparedness conference this week. One of the speakers, Dr. David Rogers, cited cracked oil and gas pipelines in the Midwest as one of the consequences of a major New Madrid earthquake. Rogers was quoted as follows by the Associated Press:

"The economic consequences are horrid," said Rogers, who has assessed responses to Hurricane Katrina in New Orleans and the Northridge earthquake in California, among other disasters. "The shock factor of having unavailable fuel would be unprecedented."

Read the full story as published by Forbes.com here.

The conference also got some TV coverage. KY-3's Dave Snider came up to Rolla yesterday morning and later got a tour of the structures lab in the civil engineering building from Dr. D.J. Belarbi.

David Rogers is also mentioned or quoted here, here and here and probably elsewhere.

P.S. The reason the rumbler was felt in places like Kansas City and Louisville, and not in Rolla, is because these Midwestern quakes MOVE UP THE RIVERS. They also presumably move down the rivers.

J. David Rogers, professor of geological engineering at Missouri University of Science and Technology, said the Wabash Valley Seismic Zone is "definitely capable of spawning 7.0 magnitude earthquakes approximately every 1,000 years. We know there was a large event about 4,600 years ago -- a magnitude 7 or above."

There also were large ones in 1891, 1968 and 1987.

"This zone has been crackin' off magnitude 5-plus events, and quite a few historic ones," Rogers said. The Missouri University of Science and Technology is based in Rolla.

One problem is that the federal or state governments haven't pumped money into research in the Wabash Valley zone like they have for the New Madrid quake zone. For example, the New Madrid zone has 13 seismographs.

"We don't even have a single seismograph in the Wabash Valley zone," he said. "We haven't spent the money looking up there as in the New Madrid zone."

That means that the shock waves for that quake were measured using instruments 100 or more miles away, in places like St. Louis, New Madrid and Kentucky.

"We're missing how much amplification you're getting at the epicenter. It's not going to tell you the severity of the shaking on the earth's surface," he said.

The 1968 quake, with its epicenter near Dale, Ill., was about 35 miles from the Wabash River. It measured a 5.3 magnitude. In June 1987, a 5.0 magnitude quake was centered in Olney, Ill., just north of today's earthquake.

Rogers said a 5.2 quake, which today's was, might cause shaking for 10 seconds and shouldn't cause a whole lot of damage.

"It might knock down a few chimneys, but we don't expect it to cause gross structural damage," Rogers said.

Via St. Louis Post-Dispatch.

You never wish for an earthquake, but sometimes they serve as real reminders to non-scientists about why they should use the available and cost-effective solutions that minimize earthquake risk to structures.

Ronaldo Luna, associate professor of civil, architectural and environmental engineering and an expert in geotechnical engineering, is on the road with 40 engineers, insurance professionals and other nonscientists as part of the an annual earthquake field trip hosted by the U.S. Geological Survey. The two-day field trip, which began yesterday, is designed to help participants understand the earthquake history of the central United States and current exposures to earthquake hazards in this area. The field-trip route crosses the heart of the New Madrid fault zone and includes parts of Tennessee, Arkansas, Kentucky, Illinois and Missouri. The tour has been cut short because of this morning’s earthquake in Illinois, which was felt by the group as they spent the night in Tennessee. Stops are made at sites that show geologic evidence of past large earthquakes, as well as methods for reducing risks.

We're keeping Dave Rogers busy this morning as he helps media tell the story of today's earthquake in Illinois. Here's why TV and newspaper reporters want to talk to him:

Dr. J. David Rogers, the Karl F. Hasselmann Chair of geological engineering at Missouri University of Science and Technology, says Midwestern earthquakes are potentially more powerful than California quakes. According to Rogers, unique geology in the Midwest increases the shaking intensity of earthquakes because seismic energy moves through the dense bedrock at very high speeds, then becomes trapped in soft sediments filling river channels and valleys. Rogers and several graduate students have been modeling synthetic seismic events in the New Madrid region, which produced magnitude 8.0 quakes in 1811 and 1812. Most of their scenarios are modeled after an 1895 earthquake with a magnitude of 6.4 that was centered in Charleston, Mo. The preliminary results are sobering, says Rogers, who is a member of Missouri's Seismic Safety Commission. Data indicates ground shaking would be magnified about 600 percent within the flood plain of the Missouri River, a development that would cause most of Missouri’s existing long-span bridges to collapse. “You don't even need a really big earthquake to do significant damage in Missouri,” Rogers says. “It could happen tomorrow.”

Today's Springfield News-Leader asks whether Missouri will be ready when "the New Madrid earthquake fault in southeast Missouri suddenly rips itself apart." Had the reporter checked with UMR's David Rogers, he would have explained that New Madrid Seismic Zone quakes pack quite a whallop.

Rogers suggests officials focus on preparing for a magnitude 6.6 to 6.8 quake -- not the 8.0 "big one" series of temblors in 1811-1812 that shook the Midwest and rang church bells in Boston. A 6.6- to 6.8-magnitude quake, similar to what took place in 1895 (illustrated at right and compared to the 6.7 earthquake in L.A. a decade ago), is more likely and could do significant damage, Rogers says.

"It's in our face here and now, not 200 or 300 years from now. This one could happen tomorrow." Rogers and several graduate students have been modeling fictional seismic events of approximately the size of an1895 quake that registered 6.6 on the Richter Scale. As part of their research, they have tried to estimate the impact such a quake would have on long-span bridges across the Missouri River. The preliminary results are sobering, Rogers says. Data indicates ground shaking would be magnified about 600 percent within the flood plain of the Missouri River, a development that would predict soil liquefaction and cause most of Missouri's existing long-span bridges to collapse. "You don't need a big earthquake to do significant damage in Missouri," Rogers says.