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




DEEP IMPACT
Waves Generated by Russian Meteor Recorded Crossing the US
by Staff Writers
Washington DC (SPX) Mar 08, 2013


Meteor trail over eastern Russia is seen in this image from the Russian Emergency Ministry. Credit: Russian Emergency Ministry.

A network of seismographic stations recorded spectacular signals from the blast waves of the meteor that landed near Chelyabinsk, Russia, as the waves crossed the United States.

The National Science Foundation- (NSF) supported stations are used to study earthquakes and the Earth's deep interior.

While thousands of earthquakes around the globe are recorded by seismometers in these stations--part of the permanent Global Seismographic Network (GSN) and EarthScope's temporary Transportable Array (TA)--signals from large meteor impacts are far less common.

The meteor explosion near Chelyabinsk on Feb. 15, 2013, generated ground motions and air pressure waves in the atmosphere. The stations picked up the signals with seismometers and air pressure sensors.

The ground motions were recorded by the GSN and the TA. The pressure waves were detected by special sensors that are part of the TA.

"The NSF-supported Global Seismic Network and EarthScope Transportable Array made spectacular recordings of the Chelyabinsk meteor's impact," says Greg Anderson, program director in NSF's Division of Earth Sciences.

"These recordings of seismic waves through the Earth, and sound waves through the atmosphere, are good examples of how these facilities can help global organizations better monitor earthquakes, clandestine nuclear tests and other threats."

Incoming! Then outgoing!
The Chelyabinsk meteor exploded in the atmosphere at approximately 9.20 a.m. local time.

The blast caused significant damage in the city, breaking thousands of windows and injuring more than 1,000 people.

Energy from the blast created pressure waves in the atmosphere that moved rapidly outward and around the globe. The blast also spread within the Earth as a seismic wave.

The two wave types--seismic wave and pressure wave--travel at very different speeds.

Waves in the ground travel quickly, at about 3.4 kilometers per second. Waves in the atmosphere are much slower, moving at about 0.3 kilometers per second, and can travel great distances.

GSN stations in Russia and Kazakhstan show the ground-traveling wave as a strong, abrupt pulse with a duration of about 30 seconds.

The atmospheric waves--referred to as infrasound--were detected across a range of inaudible frequencies and were observed at great distances on infrasound microphones.

When the infrasound waves reached the eastern United States--after traveling 8.5 hours through the atmosphere across the Arctic from the impact site in Russia--they were recorded at TA stations at the Canadian border.

The infrasound waves reached Florida three hours later, nearly 12 hours after the blast.

Infrasound sensors at TA stations along the Pacific coast and in Alaska also recorded the blast, but with signatures that were shorter and simpler than those recorded by stations in the mid-continent and along the southeastern seaboard.

The duration of the signals, and the differences between the waveforms in the east and west, scientists believe, are related to the way in which energy travels and bounces on its long path through the atmosphere.

EarthScope Transportable Array
The Transportable Array is operated by the IRIS (Incorporated Research Institutions for Seismology) Consortium as part of NSF's EarthScope Project. It consists of 400 stations traversing the United States, recording at each site along the way for two years.

Each of the TA stations was originally equipped with sensitive broadband seismometers for measuring ground motions, but in 2010, NSF awarded the University of California, San Diego, in cooperation with IRIS, funding to add pressure and infrasound sensors.

These special sensors help scientists understand how changes in pressure affect ground motions recorded by the TA's seismometers and provide a view of regional pressure changes related to weather patterns.

The sensors also record events such as tornadoes, derechos, rocket launches, chemical explosions--and meteor impacts.

The Chelyabinsk meteor is the largest signal recorded to date.

In 2013, the Transportable Array will reach states in the Northeast, completing its traverse of the contiguous United States and southern Canada.

Global Seismographic Network
The GSN's primary mission is collecting data to monitor worldwide earthquakes and to study the Earth's deep interior.

It's funded jointly by NSF and the U.S. Geological Survey and is managed and operated by IRIS in collaboration with the U.S. Geological Survey's Albuquerque Seismological Laboratory and the University of California, San Diego.

As part of a worldwide network of seismic stations, data from the GSN have contributed over the past three decades to the monitoring of nuclear explosions at test sites in the United States, the former Soviet Union, India, Pakistan and Korea. For example, GSN stations provided observations of the Korean nuclear test on Feb. 12, 2013.

.


Related Links
NSF
Asteroid and Comet Impact Danger To Earth - News and Science






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





DEEP IMPACT
Scientists at Princess Elisabeth Antarctica Discover 18kg Antarctic Meteorite
Princess Elisabeth Antarctica (SPX) Mar 06, 2013
A team of scientists working at Princess Elisabeth Antarctica have recently discovered a meteorite weighing 18kg embedded in the East Antarctic ice sheet, the largest such meteorite found in the region since 1988. The eight members of the SAMBA project, from Universite Libre de Bruxelles (ULB) and Vrije Universiteit Brussel (VUB), Japan's National Institute of Polar Research (NIPR) and Tok ... read more


DEEP IMPACT
China to use modified rocket for moon landing mission

Water On The Moon: It's Been There All Along

Building a lunar base with 3D printing

US, Europe team up for moon fly-by

DEEP IMPACT
Mars rover 'sleeping' through solar storm

Curiosity Rover's Recovery on Track

NASA's Curiosity rover to be back online next week

Short Bump Gets Robotic Arm Closer to Rock Target

DEEP IMPACT
How to predict the progress of technology

Shadows over data sharing

NASA Launches Website to Design Interplanetary Missions

Sequestration and the Civil Space Industry

DEEP IMPACT
China's fourth space launch center to be in use in two years

China to launch new manned spacecraft

Woman expected again to join next China crew roster

China's space station will be energy-efficient

DEEP IMPACT
'Goody Bag' Filled With Sample Processing Supplies Arrives on Station

ESA's Columbus Biolab Facility

SpaceX set for third mission to space station

Record Number of Students Control ISS Camera

DEEP IMPACT
Vega launcher integration continues for its April mission

SpaceX's capsule arrives at ISS

Dragon Transporting Two ISS Experiments For AMES

SpaceX Optimistic Despite Dragon Capsule Mishap

DEEP IMPACT
The Birth of a Giant Planet?

Scientists spot birth of giant planet

NASA's Kepler Mission Discovers Tiny Planet System

Kepler helps astronomers find tiny exo planet

DEEP IMPACT
SXSW kicks off with vision of a 3D printing revolution

Atoms with Quantum-Memory

Big data: Searching in large amounts of data quickly and efficiently

Neutron scattering provides data on adsorption of ions in microporous materials




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