The DEMETER satellite: Payload, Operations and Data M. Parrot LPC2E/CNRS 3A, Avenue de la Recherche 45071 Orléans cedex 2, France E-mail: mparrot@cnrs-orleans.fr Tunis, Awesome June 2009

The hypotheses about the seismo EM effect Outlines The Project The hypotheses about the seismo EM effect Observations during seismic activities Statistical analysis Conclusions Tunis, Awesome June 2009

The Project The DEMETER micro-satellite has been launched on June 29, 2004 by a Dnepr rocket from Baïkonour. The plate-form is under the CNES responsibility and the scientific payload was provided by scientific laboratories. Tunis, Awesome June 2009

The scientific objectives The scientific objectives of the DEMETER micro-satellite are related to the study of ionospheric perturbations in relation with the seismic and volcanic activities. These perturbations are interesting because they can be considered as short-term precursors (they occur between a few hours and a few days before a quake). The same payload will allow to survey the ionospheric perturbations in relation with man-made activities. Tunis, Awesome June 2009

The scientific payload The scientific payload of the DEMETER micro-satellite has several experiments: A set of electric sensors to measure the 3 components of the electric field from DC to 3.5 MHz (CETP), A three orthogonal search coil magnetometer to measure the magnetic field from a few Hz up to 20 kHz (LPCE), Two Langmuir probes to measure the density and the temperature of the electrons (ESTEC), An ion spectrometer to measure ion composition (CETP), An energetic particle analyzer (CESR). Tunis, Awesome June 2009

Tunis, Awesome June 2009

Tunis, Awesome June 2009

Tunis, Awesome June 2009

Frequency range, B 10 Hz - 20 kHz Frequency range, E DC – 3.5 MHz Measured Parameters Frequency range, B 10 Hz - 20 kHz Frequency range, E DC – 3.5 MHz Sensibility B : 1. 10-5 nT Hz-1/2 at 1 kHz Sensibility E : 0.2 µV Hz-1/2 at 500 kHz Particles: electrons 60 keV – 600 keV Ionic density: 5 102 - 5 106 ions/cm3 Ionic temperature: 1000 K - 5000 K Ionic composition: H+, He+, O+ Electron density: 102 - 5 106 cm-3 Electron temperature: 500 K - 3000 K Tunis, Awesome June 2009

The operations The orbit of DEMETER is polar, circular with an altitude of 710 km. DEMETER record data in two modes: a survey mode all around the Earth with low resolution, and a burst mode with high resolution above main seismic zones. The seismic parameters received from IPGP are merged with the orbital parameters in a special file of events. Tunis, Awesome June 2009

Tunis, Awesome June 2009

The wave experiment NEURAL NETWORK number of whistlers and dispersion. BURST MODE waveforms of 3 electric components up to 15 Hz, waveforms of 6 components of the EM field up to 1.25 kHz, waveforms of 2 components (1B + 1E) up to 20 kHz, spectra of one electric component up to 3.5 MHz, spectra of 2 components (1B + 1E) up to 20 kHz, waveforms of one electric component up to 3.5 MHz (snapshots). SURVEY MODE spectra of one electric component up to 3.5 MHz. Tunis, Awesome June 2009

Tunis, Awesome June 2009

DEMETER DATA ACQUISITION The DEMETER mission center 8 GHz 2 GHz CNES CONTROL CENTER ANCILLARY DATA - Orbit Parameters - TM station Pass-Planning - Events (orbit, satellite) - Attitude - HK OPERATION COORDINATION GROUP Science PL TM packets Science PL TM packets « back-up » PL TC PLAN EXCHANGE FILE SERVICE LPCE (MC) DEMETER DATA ACQUISITION SEISMIC DATA IPGP TM ANCILLARY DATA PROCESSING PRE-PROCESSING [L0] (Decommutation, Good Health) SCIENCE PL PROGRAMMATION GENERATION INSTRUMMENT CALIBRATIONS QUICK-LOOK PROCESSING [L0'] PHYSICAL VALUES PROCESSING [L1] Memory handling BURST zones High resolution display [L2] ARCHIVE (Science data L0, QL, L1; Earthquake data; Ancillary data) Calibration validation SCIENTIFIC USERS OPERATION BOARD PL status WEB DATA SERVER (Data L0, QL, L1, L2; Earthquake events; Ancillary data products; Mission information) Science operation coordination PL and MC events Instrument configuration LPCE (IMSC, RNF, BANT) CETP (IAP, ICE) DEMETER MISSION GROUP (Experimenters, CNES) CESR (IDP) ESTEC (ISL) Tunis, Awesome June 2009

Tunis, Awesome June 2009

Tunis, Awesome June 2009

Tunis, Awesome June 2009

One day in the DEMETER life (August 12, 2004) d = 2800 km 10 LT 22 LT Tunis, Awesome June 2009

The hypotheses about the seismo EM effect Outlines The Project The hypotheses about the seismo EM effect Observations during seismic activities Statistical analysis Conclusions Tunis, Awesome June 2009

Hypotheses on the generation mechanism of these seismo-electromagnetic perturbations: Propagation of EM waves from the ground. Only ULF waves can appear at the Earth’s surface, Propagation in a wave guide (the fault) or change in the ground resistivity? Wave-wave interaction in the ionosphere. Propagation of Acoustic-Gravity Waves. As far as they propagate, the AGW amplitude increases due the decrease of the atmospheric density Tunis, Awesome June 2009

The piezo-electric and tribo-electric effects. Apparition of electric charges at the Earth’s surface, Change of the atmospheric conductivity, Change of the atmosphere-ionosphere coupling currents The emissions of aerosols (radioactive gas or metallic ions). Transportation to ionospheric layers due to: atmospheric turbulence and thermospheric winds, increase of the atmosphere conductivity, penetration of electric fields and ion acceleration from Markson, 1978 Tunis, Awesome June 2009

First paper on the seismo-electromagnetic effects by Milne in 1890 Tunis, Awesome June 2009

Gokhberg et al. (1982) Tunis, Awesome June 2009

Observations of Seismo-Electromagnetic effects Laboratory experiment (Cress et al., GRL, 1987) Tunis, Awesome June 2009

Observations of Seismo-Electromagnetic effects Radon concentration data in a well close to Kobe Tunis, Awesome June 2009

(courtesy of P.F. Biagi) Tunis, Awesome June 2009 Ground

The hypotheses about the seismo EM effect Outlines The Project The hypotheses about the seismo EM effect Observations during seismic activities Statistical analysis Conclusions Tunis, Awesome June 2009

Examples of ionospheric perturbations in possible correlation with seismic activity Tunis, Awesome June 2009

Altitude of DEMETER Tunis, Awesome June 2009

13 Juin 2008 23:43:46 UT Lat 39.103° Long 140.668° d = 10 km M = 6.8 Tunis, Awesome June 2009

2,5 days before 200 km Tunis, Awesome June 2009

from K. Hattori Tunis, Awesome June 2009

The hypotheses about the seismo EM effect Outlines The Project The hypotheses about the seismo EM effect Observations during seismic activities Statistical analysis Conclusions Tunis, Awesome June 2009

Statistical analysis with the electric field data Tunis, Awesome June 2009

Electric field data organized by Frequencies (16) below 10 kHz 15 months of data 4385 hours of measurements Electric field data organized by Frequencies (16) below 10 kHz Magnetic local time (2) Geographic positions (bin of 4° in longitude, 2° in latitude) Kp classes (3) Seasons (2) Tunis, Awesome June 2009

Electric field map Tunis, Awesome June 2009

Probability density of the intensity of the waves in a cell Application of the central limit therorem Tunis, Awesome June 2009

de Braile, AGU, 2004 Tunis, Awesome June 2009

Superposed epoch method Time of EQ 26 June 2007 00:30:00 UT 10 Hours before ► x x x x x x x x x x x x x x x x x x x x x x x x x x Example for one EQ. When all EQs have been considered, the data in each cell are averaged. x x x x x 14 Hours 30 after x ► Tunis, Awesome June 2009

Night time VLF Electric field between 1055 – 2383 Hz 2111 EQs with M > 5.0 and d < 40 km Tunis, Awesome June 2009

3346 earthquakes with M > 4.8 and d < 40 km 2111 earthquakes Night time Tunis, Awesome June 2009

random 2111 earthquakes with M > 5.0 and d < 40 km Night time Tunis, Awesome June 2009

We observe a decrease of the electric field at ~ 1.7 kHz during night time This is the frequency cutoff of the Earth-ionosphere waveguide (h= 90 km) Tunis, Awesome June 2009

Conclusions (1/3) The main points revealed by the statistical studies are: The values of the parameters when the satellite is far from the earthquakes are similar to the values obtained when a random data set of events is used. Therefore this study shows that there is an influence of the seismic activity on the ionospheric parameters at an altitude of 700 km before the earthquakes. The perturbations are observed a few hours before the earthquakes. The perturbations are real but they are weak and only statistically revealed. Up to now nothing can be said about the possibility to predict earthquakes with the analysis of the ionospheric parameters. Tunis, Awesome June 2009

Conclusions (2/3) Statistical analysis are in progress with other parameters: Electron density Electrostatic turbulence Whistler dispersion Energetic particles VLF Transmitters Tunis, Awesome June 2009

Conclusions (3/3) 72 publications (end of May) The website of the mission: http://demeter.cnrs-orleans.fr Operations will continue at least until the beginning of 2010. Tunis, Awesome June 2009