Risk Wise

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] 162

A multi-sensor approach analysing

atmospheric signals for possible earthquake

precursors: application

of remote sensing for disaster management

Dimitar Ouzounov, Shahid Habib, NASA Goddard Space Flight Center;

Stephen D. Ambrose, NASA Headquarters, Applied Sciences Program, Disaster Management

new multi-sensor approach for analysing atmospheric

signals and the search for possible earthquake precur-

sors is being studied using science and remote sensing

techniques. The new interdisciplinary approach is still in the

early stages of validation and is based on data fusion of satel-

lite thermal infrared observations from NASA and other

national and international space assets. This technique is used

in conjunction with ground multi-parameter continuous

measurements. The method uses existing satellite sensors and

ground observations in one integrated Sensor Web framework

defined by a Lithosphere-Atmosphere-Ionosphere Coupling

(LAIC) concept.

Initial results of the research show that simultaneous satellite and

ground measurements, using an integrated web of observations,

could provide pre-earthquake alerting capabilities by combining the

information from multiple platforms. The significance of joined satel-

lite electromagnetic (EM) methodology is analysed and demonstrated

in the most recent major earthquakes in Asia – the M7.6 Kashmir

earthquake of 8 October 2005 and the Mw7.8 earthquake of 12 May

2008 in Eastern Sichuan, China.

This work contributes to the implementation strategies of the US

President’s Office of Science Technology and Policy, Subcommittee on

Disaster Reduction Grand Challenges to: “fully explore the

predictability of earthquakes based on testable and credible methods,

and provide objective reviews of predictions.”

About once a year a catastrophic earthquake of magnitude 7 (on

the Richter scale) or more strikes somewhere in the world. Such

events claim thousands of lives and cause extensive economic losses.

For example, the 12 May 2008 earthquake in Eastern Sichuan,

China caused widespread devastation with a death toll of well over

75,000 people. The cost to human life of such events is another

indication to the science community that development of an earth-

quake hazard mitigation scheme requires diverse interdisciplinary

efforts; as was suggested in 1995 by the famous seismologist Ari

Ben-Menahem: “Unless we launch a concentrated interdisciplinary

research effort, we shall always be surprised by the next major earth-

quake.”

Nevertheless, such events can trigger a cascade of follow-on events

such as tsunamis, floods, landslides and public health catastrophes

in the affected region. Such potential catastrophic

impacts are due to the growth of population, and rapid

development of the technological infrastructure. The

science community and operational agencies are strug-

gling with how to provide early detection of such

climactic events and reduce the loss to human lives and

property.

NASA, the latest review by the panel on Earthquake

Remote Precursor Sensing

and others working in this

area have found that there were many cases showing

precursory electromagnetic signals observed on the

ground and space associated with major earthquakes.

Advances in solid earth sciences and remote sensing

capabilities provide strong support to the new interdis-

ciplinary satellite studies of the electromagnetic

environment near to seismic tectonic active faults. The

observational evidence from the last 20 years confirms

the existence of EM phenomena accompanying or

preceding some of the earthquake events. Most recent

studies confirm strong coupling between the atmos-

pheric boundary layer and the ionosphere, which are

strongly related to enhanced tectonic activity.

Our latest

experience from several post-earthquake independent

analyses of more than 100 major earthquakes has been

very encouraging, and motivates us to comprehensively

address the problem for more discrete detection of future

magnitude 5.0 (M>5.0) earthquakes.

Discrete observations (temporally, spatially and spec-

trally) are spatially and temporally insufficient in coverage

of any one of these parameters to reliably determine the

earthquake precursor signals. This requires an integrated

set of observations of several physical and environmen-

tal parameters (outgoing long wave earth radiation,

ionospheric parameters, temperature and humidity of the

boundary layer, seismicity, etc.) that can be combined in

a multi-sensor system to identify earthquake precursors.

Traditionally space-based methods for earthquake

study include GPS navigation systems and

Interferometric Synthetic Aperture Radar (InSAR).

These methods measure the slow build-up of deforma-