Infrasound in the Geosciences

Henry E. Bass, Carrick Talmadge, and Kenneth Gilbert, National Center For Physical Acoustics, University of MississippiMichael Hedlin, Gerald D’Spain, and Jon Berger, Scripps Institution of Oceanography, University of California San DiegoMilton Garces and Claus Hetzer, ISLA, University of HawaiiJohn V. Olson, Charles Wilson, Curt Szuberla and Daniel Osborne, University of Alaska at FairbanksPaul Golden and Gene Herrin, Southern Methodist UniversityRichard Kromer and Pres Herrington, Sandia National LaboratoryRod Whitaker and Doug Revelle, Los Alamos National LaboratoryKeith McLaughlin, Joydeep Bhattacharyya, Bob Woodward and Bob North, SMDC Monitoring Research, Arlington, VADavid Norris and Rob Gibson, BBN Technologies, Arlington, VA

What does the infrasound community bring GEOSS?

Existing Arrays of SensorsGrowing Library of SignaturesImproved Understanding of Propagation/MetAbility to Confirm/Broaden Understanding of Events.

Available Infrasound Stations

IMS Sites

Library of Signatures - Littoral Processes

Severe Weather

Microbaroms allow storm tracking with infrasound

Electromagnetic Activity

Sprites, Aurora

source at 90 km height

Liszka, 2001: Sprites in Sweden May 26/27, 1995

Bolides

April 23, 2001~10kt

Turbulence and Atmospheric Waves

Clear air turbulence monitoringLower, middle and upper atmosphere dynamics

Improved Understanding of Infrasonic Wave Propagation

Progress in integration of required environmental information for modeling – further work required to resolve outstanding issues such as:

observed errors in azimuthphase identificationscattering and diffraction

Final goal of an operational full modeling capability (waveforms, travel times, phase velocities, amplitudes)Use of infrasound for tomography

Example - Volcanic Signals

Acoustic Surveillance for Hazardous Eruptions (ASHE)

In Cooperation with the Geological Survey of Canada and Instituto Geofisico, QuitoSmall arrays to be installed north of Quito and near Tundarahua. Data forwarded to Ottawa and Washington Area VAAC.Results ready in 2007.

Example - Tsunami Source Location

Example: Columbia TragedyA

ltit

ud

e (

km)

Trajectory in white Arrays in red CPA’s in yellow

How do we build and maintain the core

Deploy infrasound arrays with seismometers where value is to be added – arrays add value.Maintain portable infrasound equipment available for deployment.Contribute to a common data base.Document major events detected by multiple sensors – WSMR Experiments

Geophysical Events

Ground Truth Event Database is growing: SMDC Data CenterSome sources are poorly characterized

Date Type of Event Lat Lon Time (UT) Description CSS Data Available

4/23/2001 Bolide 29.9 -133.89 6:12 April 23 Bolide IS10, DLIAR, IS26, IS57, IS59, SGAR*, NVIAR, FAI

10/11/2000 Rocket 28.49 -80.58 23:17 Space Shuttle Discovery IS10*, DLIARfrom Kennedy

8/25/2000 Bolide 14.45 -106.13 1:12:25 Acapulco Bolide IS59, DLIAR, FAI

12/18/1999 Rocket 34.7 120.6 18:57 Lockheed Martin Atlas DLIAR, SGAR2AS from Vandenburg

5/22/1999 Rocket 34.7 -120.6 9:36 Air Force Titan 4B DLIAR, SGARfrom Vandenburg

11/19/1997 Explosion 33.62087 -106.48 18:00 20,000-lb C4 explosion, DLIAR, TXIAR,LSARWhite Sands Missile Range

Subset of CMR GT Database

The End