T53C-01 INVITED 13:40h
Achievements of NASDA_fs Earthquake Remote Sensing Frontier Project.
We review the achievements of NASDA_fs Earthquake Remote Sensing Frontier Project (1996-2001), together with our recent activities. Within the framework of NASDA_fs frontier project, we have obtained a lot of interesting phenomena by means of different observational methods (passive and active measurements, satellite observations etc.). From the standpoint of short-term earthquake prediction, it is recently agreed that there are two promising methods; (1) ULF emissions and (2) ionospheric perturbations as revealed from subionospheric VLF/LF propagation. We show mainly the results on these two subjects.
T53C-02 INVITED 13:55h
First Results Obtained With the Micro-Satellite DEMETER
Among all earthquake precursors, those related to electromagnetic effects are the most puzzling, and the many possible sources of noise are cause of lively controversies. A large number of laboratory experiments clearly suggest that micro-fracturing is associated with the appearance of spontaneous charge production (electrification) and transient Electric or ElectroMagnetic (EM) Emission. Other hypotheses to explain these electromagnetic effects are related to fluid circulation in the crust, gas emanation, acoustic-gravity waves,.Many electric and magnetic pre-seismic and co-seismic effects have been reported in the past as well as ionospheric perturbations. DEMETER is a micro-satellite dedicated to the study of such perturbations in order to understand their generation mechanisms. DEMETER has been launched by CNES at the end of June 2004. The aim of this paper is to describe the scientific objectives of this mission and all possible means to achieve these objectives. The payload of the DEMETER microsatellite allow to measure waves and also some important plasma parameters (ion composition, electron density and temperature, energetic particles). The scientific payload is composed of several sensors: - Three electric and three magnetic sensors (6 components of the electromagnetic field to investigate from DC up to 3.5 MHz), - A Langmuir probe, - An ion spectrometer, and, - An energetic particle analyzer. There are two modes of operation: (i) a survey mode to record low bit rate data all around the Earth, and (ii) a burst mode to record high bit rate data above seismic regions. Data are processed in a mission center and are available for scientific users from a web site located in Orleans. The first results obtained from DEMETER will be shown.
<a href='http://demeter.cnrs-orleans.fr' >http://demeter.cnrs-orleans.fr
T53C-03 INVITED 14:10h
Description and Testing of ESPERIA Instruments (ARINA and LAZIO-SIRAD) in Space.
ESPERIA is an equatorial magnetic, plasma and particle mission planned with a LEO small satellite for monitoring perturbations in the topside ionosphere and for defining the near-Earth magnetic environment. The project aims at reconcile these phenomena with Sun and Earth activities. So, in principle, Earth natural disasters, as earthquakes, the impact of anthropogenic electromagnetic radiation on the near-Earth space, atmospheric electromagnetic emissions during thunderstorm activity, and effects of sun and cosmic rays on the geomagnetic cavity can be studied by this mission. The ESPERIA Phase A Study, which has been realized for the Italian Space Agency (ASI), is mainly concerned with detecting seismic related signals from the Earth's surface. In particular, electromagnetic emissions related to the strong earthquake and possibly caused by stress changes in the Earth's crust, are a main scientific objective of this mission. ESPERIA includes a modular multi-instrument science payload constituted by a Magnetic Field Analyzer (two flux-gate and search-coil vector magnetometers), an Electric Field Analyzer (a constellation of ten Electric Probes), a Particle Detector, and an Ionospheric Plasma Analyzer (Langmuir Probe and Retarding Potential Analyzer). Most of these instruments are of large use in near-Earth Space investigations, therefore ESPERIA, with some relatively small changes and/or augmentation of its Payload, can easily be adapted for studying most of the applications mentioned above. So ESPERIA can also be seen as an equatorial coordinated and simultaneous complement to polar missions like SWARM, or "Living with a Star" NASA Program, etc. Two ESPERIA instruments (a particle detector and a search-coil magnetometer, included in the ARINA and LAZIO-SIRAD experiments) have been realized and will be tested in space. ARINA, which launch is scheduled for mid-2005 on board the RESURS DK-1 Russian LEO satellite, will perform particle measurements on a polar orbit. LAZIO-SIRAD will be installed on board the ISS next April 2005 to carry out magnetic and particle measurements.
T53C-04 INVITED 14:25h
Ionospheric anomalies registered around the time of several strong earthquakes in United States
Regardless worldwide studies of anomalous variations of the electron concentration appearing in the ionosphere few days before the seismic shock and named ionospheric precursors of earthquakes, the facts on such events over the United States are very poor. The paper intends to fill this gap presenting data on several well known strong earthquakes in the United States: Good Friday earthquake of March 1964, Mammoth Lake seismic swarm of May 1980, Hector Mine earthquake of 1999, and recent San Simeon earthquake of December 2003. The data of topside sounders of Alouette and Intercosmos-19 satellites are used, as well as GPS total electron content measurements. The physical mechanism of the seismo-ionospheric coupling is discussed together with possible application techniques for the ionospheric precursors identification.
T53C-05 14:40h
Geosynchronous Weather Satellite Thermal IR Measurements Prior to 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 fourteen 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. Spacecraft and sensor ephemeris and the horizontal displacement due to elevation were all factored in, and final adjustment for minor satellite deviations (related to roll, pitch, and yaw) were made by using image-to-image tiepoint correlations. Reliance upon visual clues in an image (frequently the subject of debate in the past) is not required. 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 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 will help 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.
T53C-06 14:55h
TIR Satellite Techniques for monitoring the Earthquake active regions:review of the limits, achievements and perspectives.
Space-time fluctuations 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. Despite the increasing number of such observations and some claimed success in earthquake prediction a general consensus of the scientific community regarding methods, models and results of such studies is still far from being achieved. Main problems regard data analysis (how distinguish normal from anomalous TIR signal fluctuations?) and interpretation (which statistical significance have the space-time correlation observed/suggested between TIR signal transient and earthquake occurrence?) often done without a convincing validation/confutation approach. On the other hand, 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. In this context the potential of satellite techniques using Earth's thermally emitted radiation to monitor seismically active areas will be presented considering: a) recent progresses obtained (on several earthquakes occurred in Europe, Africa and America) from the analysis of several years of satellite observations; b) shared knowledge and still open problems; c) actual perspective of research in this field.
T53C-07 15:10h
Simultaneous ELF Magnetic Field Monitoring of Earthquakes from a Nano-satellite (QuakeSat) and a Ground Network
On June 30 2004, QuakeFinder LLC, in collaboration with Stanford University and Lockheed Martin, launched a 4.5 kg nanosatellite called QuakeSat into an 840 km circular, sun-synch orbit. In addition to the student teaching goals, the satellite was a prototype for a research satellite to study whether Extremely-Low-Frequency (ELF) magnetic field disturbances occurred before or after large earthquakes. The frequency response for QuakeSat's single-axis search coil magnetometer and ELF receiver was 1-1000 Hz in 4 bands. The overall mission also had a ground component, namely a network of 35 three-axis magnetometer sensors, deployed every 30 km along major faults (e.g. San Andreas) in California. The frequency response of these ELF receivers was 0.1 to 4 Hz. and they had a 10km range. Both the space and ground-based systems were designed to record raw, time series data, and the objectives were not only to determine if earthquake-generated ELF signals exist, but to characterize them in both time and frequency and to distinguish them from the many other magnetic signals present in space and near the ground. This paper addresses a case study of the Dec. 22 2004, M6.4 San Simeon earthquake in California, and compares both space and ground ELF signatures. Preliminary results of the satellite collections showed unique signals prior to and after the San Simeon quake, as well as several other large world-wide quakes. Ground collections were inconclusive since the 4 closest of the 35 sensors were more than 60 km and 2 parallel fault traces from the epicenter.
<a href='http://www.quakefinder.com' >http://www.quakefinder.com
T53C-08 15:25h
Recent Results in Geoelectrical Studies od a Seismic Area in Southern Apennine Chain (Italy).
Since 1991 it was installed a geophysical monitoring network able to detect geoelectrical, geochemical and seismometric parameters in a seismic active area of Southern Italy. To date a very large data set of ULF electrical time series is available and the possible correlation between anomalous electrical signals and local earthquake activity can be carried out using robust filtering procedures for noise reduction and multifractal techniques for identifying extreme events. Recently the monitoring activity has been focused on Val d'Agri area representing one of the most active seismic zone of Southern Apennine chain. The Val d'Agri is a NW-SE trending intermontane basin formed after Miocene-Pliocen shortening events and controlled by high-angle trastensional and extensional active faults. In this work some recent results regarding the analysis of observational evidences of anomalous electrical signals are analysed and discussed. Finally, for better exploring the site effects governing the electrical signals we perfomed shallow and deep electrical resistivity tomographies in the investigated areas. The possibility to have extremely long period of electrical measurements, the application of novel fractal and multifractal techniques, the knowledge of resisistivity subsurface patterns close the measuring stations disclose the way to better understand the space-time dynamics of electrical signals in the study area.