Magnitude 8.0 earthquake in Samoa, largest of 2009

Here is today's record on the Franklin and Marshall seismograph:


The U.S. Geological Survey lists this as the largest quake so far of 2009.

The tsunami warning has been cancelled.

Here is the basic info:

Magnitude	8.0
Date-Time	Tuesday, September 29, 2009 at 17:48:11 UTC Tuesday, September 29, 2009 at 06:48:11 AM at epicenter Time of Earthquake in other Time Zones
Location	15.558°S, 172.073°W
Depth	18 km (11.2 miles) set by location program
Region	SAMOA ISLANDS REGION

Best of the Geoblogosphere

I don't link to many other blogs from here. I've kind of restricted myself to blogs that focus largely on earthquakes and that other endothermal process of volcanoes, and that have entries on a more or less weekly basis.

But of course, there are many others. Here is a list from last December of 100 best earth science blogs. I'd only been here for a couple of months at the time. Maybe I will crack into the next version of this list.

from http://datamining.typepad.com/

Recovery funds for LCSN

From LDEO:

"That rumbling you feel is not necessarily a passing subway. New York City and the surrounding region gets a surprising number of small earthquakes, and a 2008 study from the region’s network of seismographs, run by Lamont-Doherty Earth Observatory, suggests that the risk of a damaging one is not negligible. This week, the federal government announced a major upgrade to that network.

"Lamont will receive $255,000 grant under the American Recovery and Reinvestment Act to beef up cables, power supplies and other hardware, and add monitoring staff for its 34 locations from Vermont down to Maryland. U.S. Representative Eliot Engel announced the grant, saying: “Because of the density of the population and the presence of such facilities as the Indian Point Nuclear Power Facility, it is essential that we monitor for [earthquakes].” Lamont is part of a national network, run in cooperation with the U.S. Geological Survey."

I'm wondering how they are going to find the $18 million blogging bonus I thought I was going to get out of that grant.

No rest for our very own Charles Scharnberger

Teaching Himself By Teaching Others

Intelligencer Journal-Lancaster New Era (PA)
Monday, August 24, 2009

Author: Lori Van Ingen

Retired Millersville University professor Charles Scharnberger believes learning throughout your adult life is important, and it's never too late to start.

Scharnberger said he believes that, in part, because of his father.


His father never graduated from high school, but when he retired at 65, he got a GED and then went on to get a college degree when he was in his 70s.

"That has particularly inspired me that it is never too late to learn," Scharnberger said. To that end, he teaches science classes for seniors.

Scharnberger finds that people who take lifelong-learner classes are interested and engaged in the subjects and bring their own life experiences to them.

"It makes it fun to teach these classes," he said.

He said there are several differences between lifelong learners and the average college-age student.

The senior lifelong learners are more relaxed than the college-age student, he said. They are not obsessed with grades; they are there because they really want to learn.

The participants in these lifelong learning classes are more or less the same age as the 66-year-old Scharnberger , so they share a common perception of things and come from the same point of reference, he said.

A native of St. Louis, Scharnberger earned his undergraduate degree in geology from Amherst College and his doctorate in geology from Washington University in St. Louis.

"My area really is geophysics - or physics applied to the earth. However, I taught a course in astrophysics," Scharnberger said.

Lancaster seismic survey traverse

Here is a map of the seismic traverse through Lancaster County.

This crosses three physiographic provinces: the Triassic lowlands in the northern part of the county, the Piedmont lowlands in the central part of the county, and the Piedmont uplands in the southern part of the county.

Will the seismic survey cause earthquakes?

From the Pennsylvania Geological Survey:

Does seismic surveying cause earthquakes or damage to property?

Seismic data collection does not cause earthquakes. Unless you are standing quite close, within a few feet of the equipment, you will not notice the vibrations from either the weight drop or the vibrating weight.

The risk of any damage comes from placing the weight on top of a shallowly buried pipe or cable. Part of the work prior to the start of the data collection is to identify the buried utilities in the data collection area. The location of these utilities within the public rights-of-way is generally well known, so the risk of damage is quite low. In the unlikely event any damage occurs from the work, the contractor is fully insured and will correct the problem quickly.

Download the entire circular here.

Seismic survey in Lancaster County

I've been away for a bit: archaeomagnetic sampling and magnetic surveying at the Etruscan site of Poggio Colla in Italy; improving my field geophysics with folks at the Bayerisches Landesamt für Denkmalpflege in Munich; presenting a talk on magnetic properties of legacy sediments at the IAGA symposium in Sopron, Hungary; and along the way also enjoying the Venice Biennale and Budapest.

Anyway, what is shaking around here these days is seismic, but not an earthquake, It's a big truck. Lancaster County is getting "x-rayed" via vibroseis. Funding comes from Pennsylvania's carbon sequestration program.

Here is the full newspaper story, by PJ Reilly, from the Lancaster Intelligencer Journal, Jun 17, 2009:

A statewide project aimed at reducing Pennsylvania's carbon dioxide emissions could provide a first look at what's below the surface of Lancaster County.

"No one's ever drilled it deep," said Jay Parrish, director of the Bureau of Topographic and Geologic Survey for the state Department of Conservation and Natural Resources. "No one's ever done seismic work. All we know is what's at the surface.

"Everybody has seen the surface of Lancaster County for 250 years. Go down 3,000 feet and it's a complete mystery."

If his funding holds up, Parrish hopes to deploy a team to Lancaster County in August to literally pound the ground, north to south and from end to end, and take seismic readings to develop a picture of what lies deep beneath the surface.

"It's like a new world no one has ever looked at," he said. "We have no idea what's here."

DCNR is studying Pennsylvania's geology as part of the requirements of House Bill 2200, which was signed into law in October by Gov. Ed Rendell.

The bill orders DCNR to evaluate the state's potential for "geologic carbon sequestration."

According to the agency's Web site, that's a process in which carbon dioxide emissions are captured at coal-fired industrial plants before they are released into the atmosphere for injection and storage deep underground.

Pennsylvania ranks third among all 50 states for its total emissions of carbon dioxide, which is a greenhouse gas linked to global warming.

One percent of all the carbon dioxide emitted into the atmosphere in the world comes from Pennsylvania, Parrish said.

"As part of a broader portfolio of technologies, geologic sequestration appears to be capable of playing an important role in stabilizing carbon dioxide concentrations in the atmosphere," DCNR's Web site states.

Preliminary studies and general knowledge of Pennsylvania's geology suggest it is well suited for geologic carbon sequestration, which requires reservoirs a half-mile or more underground that are sealed by impermeable layers of rock, the Web site states.

Four primary reservoir areas DCNR expects to find are deep saline formations, depleted and producing oil and gas fields, coal beds that can't be mined and organic-rich shales.

Parrish, who was director of Lancaster County Geographic Information Systems department from 1997 to 2001, said his DCNR bureau has been assigned the task of studying the entire state to find such areas and others that might be suitable for storing carbon dioxide.

Scientists already know what lies beneath many areas of Pennsylvania, where coal mining and gas- and oil-well drilling have been going on for years.

But the extreme southeast corner of the state, including Lancaster County, is unexplored territory.

"Theoretically, there's no oil here, and that's why nobody has ever looked," Parrish said.

Discovering what lies beneath the county is important, according to Parrish, not only to see if the potential for carbon sequestration exists here, but also to simply have the subsurface data available.

"What does it mean to the average person?" he said. "It means there's a better understanding of the rocks under them, and that leads to every aspect of life, because you have radon flows, you have earthquakes, you have sinkholes.

"You just don't know what potential is there, and you also don't know, in the future, what may be useful information to have."

On Dec. 27, an earthquake measuring 3.4 on the Richter scale rattled Lancaster County. The epicenter was just west of Manheim Borough.

That's one of the areas Parrish wants to explore. He said scientists suspect there's a fault there, based on formations found in some local quarries.

"What we're looking at are little tiny thrusts at the top, so we have a good indication there's a fault there," he said. "But we don't know, maybe there's a huge faulted thrust underneath."

DCNR has budgeted about $3 million to collect seismic data from 41 of Pennsylvania's 67 counties, including Lancaster.

Parrish said the "project is in a constant state of flux" and "my priorities change from week to week," which could mean there won't be enough money to study Lancaster County.

For now, however, Parrish said the plan is for a seismic team to descend on the county in August.

He said it would take about three weeks to get readings along a north-south line through the heart of the county.

Since most of Pennsylvania's geologic formations run east to west, a north-south survey near the center of Lancaster County will give scientists a "pretty good idea" of what the whole county looks like beneath the surface, Parrish said.

To collect data, a large truck carrying a heavy weight would crawl along back roads at a rate of about 3 miles per day. Highways generate too much noise, which would interfere with the seismic readings, Parrish said.

Periodically along the route, the weight would be pounded on the ground and a series of small seismometers attached to a cable, which would be extended for three miles on both sides of the truck, would track the vibrations.

The data would be plugged into a computer "to give us a nice picture of the underground" up to three miles deep, Parrish said.

Ideally, Parrish would like to take readings on a perfectly straight line down the center of the county.

"Obviously, that's not possible with the roads we have around here," he said.

The line of readings likely will zig-zag along public roads.

Once he knows for certain there's enough money to study Lancaster County, Parrish plans to map out a work route and then contact officials in municipalities along that route to let them know what's happening.

"It's going to be a pretty big production that's going to attract a lot of attention," he said. "And we want people to know ahead of time what's going on."