S42B-01 INVITED
TIR Satellite Techniques for Monitoring the Earthquake Active Regions: Achievements and Perspectives
Short-time variations of Earth's emitted Thermal Infrared (TIR) radiation observed from satellite,months to weeks before earthquakes occurrence, have been, by several authors interpreted as pre-seismic signals.Different data analysis methods have been proposed in order to identify space-time TIR anomalies possibly related to Earthquake occurrence. Several physical models have been proposed that, in principle, could explain not only such a correlation but also justify the occurrence of other (geochemical, geo- electrical etc.) precursory phenomena. Still problems exist which are related to data analysis (how distinguish normal from anomalous TIR signal fluctuations?) as well to interpretation (which statistical significance have the space-time correlation observed /suggested between TIR signal transient and earthquake occurrence?). All these aspect will be discussed in order to offer a critical assessment of the potential contribution of TIR satellite techniques for Earthquake active regions monitoring.
S42B-02
Joint Evaluation of EM Signals Detected Around the Time of Major Earthquakes
We present results from our studies of atmospheric and ionospheric electromagnetic (EM) signals preceding major earthquakes. This study examines possible associations relating anomalous changes of thermal and ionospheric parameters observed around the time of several strong earthquakes (M8.0 in Peru and 1999-2005 in California). Our approach requires an integrated analysis of several physical and environmental parameters (thermal infrared electromagnetic fields, latent heat flux, ionospheric parameters, specifically GPS/TEC, DEMETER and electron density, air temperature and humidity of the boundary layer, and seismicity) that have been found to be associated with impending earthquakes. The ionospheric and atmospheric observational methodology we present is based on a joint analysis of: (1) satellite long-wavelength radiation data form NOAA; (2) surface latent heat flux (SLHF); (3) GPS/TEC and DEMETER; and (4) thermal infrared data from (NASA EOS/MODIS) together with ground air temperature and humidity measurements. Our latest understanding from several post-earthquake independent analyses takes into account the problem of proper evaluation of such alarm techniques for upcoming major (M>5.5, depth<50km) earthquakes in a comprehensive and systematic fashion. We evaluate and compare the observed EM signals preceding the latest M8.0 earthquake in Peru (08/15/2007) and EM signals found before the major events in California, using the same methodology. We found evidence of the systematic appearance of both atmospheric and ionospheric anomalies preceding most of these major events. Nighttime TIR signals, approximately a week before the earthquakes, corresponded with an increase of SLHF and air temperature; these were followed by significant variations in the ionospheric TEC measurements above the epicenters. Our findings are consistent with the most recent theoretical model of Lithosphere-Atmosphere-Ionosphere coupling between the crust and the atmosphere/ionosphere proposed by Pulinets et al, (2004, 2006)
S42B-03
Geosynchronous Weather Satellite Nightly TIR Cooling Curves and Earthquakes
Thermal anomalies prior to earthquakes have been a controversial topic for some time. Previous investigations of three earthquake events by the authors showed thermal changes, and as a result a more systematic analysis of over fifteen events, representing a range of magnitudes and epicenter depths was undertaken. Earthquakes associated with plate movement (strike-slip and thrust faulting), rather than volcanism, were to be considered. It was the purpose of this study to determine if thermal anomalies could be found in association with known earthquakes by systematically co-registering geosynchronous weather satellite images at the sub-pixel level and then determining if statistically significant responses had occurred prior to an event. The automatic co- registration procedures used for this task to accommodate all properties particular to weather satellite observations taken at night. The technique relies on the general condition where ground cools after sunset. The technique applies best to the use of the geosynchronous weather satellites (GOES,and Meteosat), where images are taken every thirty minutes. Use of the geosynchronous satellites also reduces the potential for miscalculation of trends due to weather front movement or local cloud/fog formation. The data analyzed for each earthquake includes 10 days prior to each event and 5 days after the event as well as the day of the event. The data are for every half hour from sunset to dawn, thermal IR bands. We also obtained the same Julian dates of the data for the three previous years to use as a baseline. The data sets were used to systematically measure the observance of thermal anomalies in two key contexts. First is the degree any thermal anomaly just prior to an event can be demonstrated to deviate from a baseline thermal profile of nightly cooling derived from the previous three years and recorded weather history. Second is the possibility to compare the earthquake epicenter with nearby regions having similar or different geology using the same imagery but no history of seismic activity. This experimental design has helped address questions regarding the "uniqueness" of thermal anomalies observed by us and others previously, and help characterize the observed thermal responses under a variety of magnitude, depth, and geologic conditions.
S42B-04
Energies associated with the Sumatra Earthquakes of December 26, 2004 and March 28, 2005
We consider all possible energies before and after the major Sumatra earthquakes of 26 December 2004 and 28 March 2005. We primarily examine the plate-movement in the earthquake of 26 December 2004 rather than the physics of the associated tsunami.. We evaluate mechanical and thermal energies, motivated in part by exploring the physics of associated phenomena. We compare the energies of the earthquakes, the moments, energies associated with change of the rotational period of the Earth as well as latent heat released prior to the events. We keep track of the overall thermal and mechanical associated energies as well as global effects. In such large events, associated phenomena may stand out energetically in measurements above variance that arises from other geophysical processes. We discuss here that as we have more energy budget information for this large event, it can be used to establish earthquake energy phenomenology.
S42B-05
Observations of Electromagnetic Perturbations Shortly Before Earthquakes Onboard a Low-Orbiting Spacecraft
We present a statistical study of intensity of VLF (up to 10 kHz) electromagnetic waves in the top side ionosphere above the earthquakes. More than 2.5 years of data recorded by the French micro-satellite DEMETER (altitude of orbit 700 km) and a specially developed two-step data processing method have been used. In the first step, a map of electromagnetic emissions that contains a statistical description of wave intensity at a given point of the satellite orbit under given conditions is constructed. In the second step, the wave intensity close to earthquakes is evaluated. Changes of wave intensity related to the seismic activity are investigated and their statistical significance is analyzed. Earthquakes with magnitude larger than 4.8 that occurred all over the world during the analyzed period (~ 9000 earthquakes) have been included in the study. It is shown that the observed intensity of electromagnetic waves decreases during the night by 4-6 dB shortly before earthquakes (up to 4 hours before the time of the main shock). Spatial scale of the affected area is approximately 300 km. A possible explanation of the observed effects is suggested. http://os.matfyz.cz/papers/agu2007/
S42B-06
The Capability of Space Mission to Study the Ionosphere and Electromagnetic Disturbances Related to Seismicn Activity
Based on observational evidence, we suggest that a series of observational and modeling experiments could be carried out to demonstrate the viability of a satellite based earthquake prediction program based on a search for earthquake precursors. The satellite project has an exploratory character and aims first of all to detect the ionosphere plasma and the electromagnetic anomalies related to seismic, meteo and human activity. The observations made by the satellite have the very great advantage of very rapidly covering almost the whole of the active seismic regions in the world and monitoring the effects of a large number of earthquakes. The micro - satellite COMPASS - 2 launched on May 26, 2006. It has the capacity to carry out precise and systematic measurements around the Earth and thus to collect a maximum number of events. Without modifying the payload, like COMPASS - 2, is capable for studying the influence of storms in relation between Sun and Earth, and of assessing the impact of human activities on the ionosphere. The detailed COMPASS - 2 mission and payload description and also some results of measurements are presented. We present electrodynamic model of the atmosphere - ionosphere coupling for interpretation of satellite data. Our model gives an explanation to some electromagnetic and plasma phenomena preceding typhoons and earthquakes by amplification of DC electric field in the ionosphere over disturbed region. This field is connected with the conductivity current flowing in the atmosphere - ionosphere electric circuit, which is formed by external electric currents generated in the lower atmosphere disturbed by typhoon and earthquake preparation processes. Appearance of such currents is associated with upward transport of charged water drops and aerosols in hurricane convection zone and enhancement of charge aerosols emanation with soil gases into the atmosphere caused by growing seismic activity. The most important property of this mechanism is that numerous electromagnetic and plasma effects can be explained by the operation of only one source - an amplification of DC electric field in the ionosphere. This source is controlled by the dynamics of atmospheric processes through modification of electrical parameters of the lower atmosphere and seismic processes. The presented model could be applied to studies of the plasma and electromagnetic effects of large - scale natural and technological disasters. http://www.izmiran.ru
S42B-07
Statistical studies of ionospheric parameters recorded by the satellite DEMETER during seismic activity
DEMETER is an ionospheric micro-satellite launched on a polar orbit at an altitude of 710 km. Its main scientific objective is to study the ionospheric perturbations in relation with seismic activity, and then, its scientific payload allows to measure electromagnetic waves and plasma parameters all around the Earth except in the auroral zones. Two specific parameters are taken into account in this paper: the electron density and the electrostatic turbulence. First the paper will show specific events where the electron density and the electrostatic turbulence are perturbed prior to large earthquakes above the future epicentre. Although, these examples have been carefully selected (close in time and space to the earthquakes, abnormal variations relative to the background level for the same location, the same local time and the same magnetic activity) it is always possible that the perturbations are due to other natural mechanisms because the ionosphere is highly variable and mainly under the control of the sun. Only a statistical analysis of the data is able to remove this ambiguity. The statistic is done as functions of the geographic position, the local time, and the magnetic activity. Geographical maps with average data are obtained to be used as background levels, and the superposed epoch method is applied to merge the data recorded during seismic activity. In relation to previous presentations the data set has been increased because we have now more than three years of data and a comparison is done when we remove the aftershocks from the statistics because pre- and post-seismic effects can be mixed.
S42B-08
The possible statistical relation of Pc1 pulsations to Earthquake occurrence at low latitudes
It has been suggested in the literature that seismic activity may be preceded by a variety of phenomena, including ultra-low-frequency (ULF) magnetic pulsations, changes in the local ionospheric electron number density, and even geomagnetic activity (in a causal sense or otherwise). In the present study, we test this hypothesis using 8 years of search-coil magnetometer data recorded in Parkfield, California. We use a newly developed identification algorithm to automatically detect and classify all wave events in the Pc1 (0.2-5 Hz) frequency range in our data set, and compare these events to a catalog of local Earthquakes. Pc1 events are believed to be generated in the equatorial magnetosphere, propagate along magnetic field lines to the high latitude ionosphere, and further propagate to low latitudes within the F2-layer ionospheric density duct leaking down to the ground due to the finite conductivity of the E-layer. Thus, we look for changes in detected Pc1 characteristics coincident with Earthquakes, which would act as a proxy for local ionospheric changes. Results of our statistical analysis are presented and discussed in the context of pre-seismic ionospheric modifications.