Free Newsletters - Space - Defense - Environment - Energy - Solar - Nuclear
..
. 24/7 Space News .




SHAKE AND BLOW
Penn Research Helps Paint Finer Picture of Massive 1700 Earthquake
by Staff Writers
Philadelphia PA (SPX) May 22, 2013


Benjamin Horton and Andrea Hawkes in the field.

In 1700, a massive earthquake struck the west coast of North America. Though it was powerful enough to cause a tsunami as far as Japan, a lack of local documentation has made studying this historic event challenging.

Now, researchers from the University of Pennsylvania have helped unlock this geological mystery using a fossil-based technique. Their work provides a finer-grained portrait of this earthquake and the changes in coastal land level it produced, enabling modelers to better prepare for future events.

Penn's team includes Benjamin Horton, associate professor and director of the Sea Level Research Laboratory in the Department of Earth and Environmental Science in the School of Arts and Sciences, along with then lab members Simon Engelhart and Andrea Hawkes.

They collaborated with researchers from Canada's University of Victoria, the National Taiwan University, the Geological Survey of Canada and the United States Geological Survey.

The Cascadia Subduction Zone runs along the Pacific Northwest coast of the United States to Vancouver Island in Canada.

This major fault line is capable of producing megathrust earthquakes 9.0 or higher, though, due to a dearth of observations or historical records, this trait was only discovered within the last several decades from geology records. The Lewis and Clark expedition did not make the first extensive surveys of the region until more than 100 years later, and contemporaneous aboriginal accounts were scarce and incomplete.

The 1700 Cascadia event was better documented in Japan than in the Americas. Records of the "orphan tsunami" - so named because its "parent" earthquake was too far away to be felt - gave earth scientists hints that this subduction zone was capable of such massive seismic activity. Geological studies provided information about the earthquake, but many critical details remained lost to history.

"Previous research had determined the timing and the magnitude, but what we didn't know was how the rupture happened," Horton said. "Did it rupture in one big long segment, more than a thousand kilometers, or did it rupture in parcels?"

To provide a clearer picture of how the earthquake occurred, Horton and his colleagues applied a technique they have used in assessing historic sea-level rise. They traveled to various sites along the Cascadia subduction zone, taking core samples from up and down the coast and working with local researchers who donated pre-existing data sets.

The researchers' targets were microscopic fossils known as foraminifera. Through radiocarbon dating and an analysis of different species' positions with the cores over time, the researchers were able to piece together a historical picture of the changes in land and sea level along the coastline. The research revealed how much the coast suddenly subsided during the earthquake. This subsidence was used to infer how much the tectonic plates moved during the earthquake.

"What we were able to show for the first time is that the rupture of Cascadia was heterogeneous, making it similar to what happened with the recent major earthquakes in Japan, Chile and Sumatra," Horton said.

This level of regional detail for land level changes is critical for modeling and disaster planning.

"It's only when you have that data that you can start to build accurate models of earthquake ruptures and tsunami inundation," Horton said. "There were areas of the west coast of the United States that were more susceptible to larger coastal subsidence than others."

The Cascadia subduction zone is of particular interest to geologists and coastal managers because geological evidence points to recurring seismic activity along the fault line, with intervals between 300 and 500 years. With the last major event occurring in 1700, another earthquake could be on the horizon. A better understanding of how such an event might unfold has the potential to save lives.

"The next Cascadia earthquake has the potential to be the biggest natural disaster that the Unites States will have to come to terms with - far bigger than Sandy or even Katrina," Horton said. "It would happen with very little warning; some areas of Oregon will have less than 20 minutes to evacuate before a large tsunami will inundate the coastline like in Sumatra in 2004 and Japan in 2011."

The research was supported by the National Science Foundation, the United States Geological Survey and the University of Victoria. Simon Engelhart and Andrea Hawkes are now assistant professors at the University of Rhode Island and the University of North Carolina, respectively. Their co-authors were Pei-Ling Wang of the University of Victoria and National Taiwan University, Kelin Wang of the University of Victoria and the Geological Survey of Canada's Pacific Geoscience Centre, Alan Nelson of the United States Geological Survey's Geologic Hazards Science Center and Robert Witter of the United States Geological Survey's Alaska Science Center. The research was published in the Journal of Geophysical Research: Solid Earth.

.


Related Links
University of Pennsylvania
Bringing Order To A World Of Disasters
When the Earth Quakes
A world of storm and tempest






Comment on this article via your Facebook, Yahoo, AOL, Hotmail login.

Share this article via these popular social media networks
del.icio.usdel.icio.us DiggDigg RedditReddit GoogleGoogle




Memory Foam Mattress Review
Newsletters :: SpaceDaily :: SpaceWar :: TerraDaily :: Energy Daily
XML Feeds :: Space News :: Earth News :: War News :: Solar Energy News





SHAKE AND BLOW
6.0 quake off Russia's far-east Kamchatka coastline
Moscow (AFP) May 21, 2013
A 6.0-magnitude earthquake struck Russia's Kamchatka Peninsula early Tuesday followed by a series of strong after-shocks, the US Geological Survey said. The first quake struck at a depth of 33 kilometres (20 miles) at 0155 GMT, 136 kilometres east-southeast of the Russian city of Petropavlovsk-Kamchatsky, the USGS reported. It was followed by three after-shocks, the strongest of which me ... read more


SHAKE AND BLOW
Bright Explosion on the Moon

NASA says meteor impact on the moon glowed like a star

Where on Earth did the moon's water come from

Water on moon, Earth have a common source

SHAKE AND BLOW
NASA Mars Rover Curiosity Drills Second Rock Target

Mars Icebreaker Life Mission

Nine-Year-Old Mars Rover Passes 40-Year-Old Record

NASA Probe Counts Space Rock Impacts on Mars

SHAKE AND BLOW
British astronaut 'Major Tim' to fly to ISS

Danish Space Venture ready for lift off

Researchers use graphene quantum dots to detect humidity and pressure

Outside View: Patents laws and suffering innovators

SHAKE AND BLOW
China launches communications satellite

On Course for Shenzhou 10

Yuanwang III, VI depart for space-tracking missions

Shenzhou's Shadow Crew

SHAKE AND BLOW
Mice, gerbils perish in Russia space flight

Star Canadian spaceman back on Earth, relishing fresh air

ISS Statistics Tell the Story of Science in Orbit

Spaceman says goodbye to ISS with David Bowie classic

SHAKE AND BLOW
O3b Networks' initial satellite is fueled for Arianespace's upcoming Soyuz launch from the Spaceport

Ariane Flight VA214's launch vehicle marks a preparation milestone

ILS Proton Successfully Launches EUTELSAT 3D for Eutelsat

Russia's Proton-M Spacecraft Set to Orbit French Satellite

SHAKE AND BLOW
Critical Kepler Reaction Wheel Fails: Mission End In Sight

Sifting Through the Atmosphere's of Far-Off Worlds

New Method of Finding Planets Scores its First Discovery

Team Takes Part in Discovering New Planet

SHAKE AND BLOW
NASA Seeks High-Performance Spaceflight Computing Capabilities

SPUTNIX is granted a license for space activity

Stanford Engineers' New Metamaterial Doubles Up on Invisibility

Observation of second sound in a quantum gas




The content herein, unless otherwise known to be public domain, are Copyright 1995-2014 - Space Media Network. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA Portal Reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. Advertising does not imply endorsement,agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. Privacy Statement