Earths Many Voices a Unified Theory for Pre-Earthquake Signals

Earths Many Voices a Unified Theory for Pre-Earthquake Signals Earths Many Voices a Unified Theory for Pre-Earthquake Signals CITRIS Distinguished Speaker: Friedemann Freund from NASA Friedemann T. Freund NASA Ames Research Center, Earth Science Division, Moffett Field, CA 94035, California Abstract: In this talk, I will discuss the solid-state physics of rocks and earthquake precursors. Earthquake precursor phenomena have been known for some time. They are caused by stresses that build up in crustal rocks. As we have found in the laboratory, these stresses more precisely, differential stresses and strains activate mobile positive charge carriers (defect electrons in the oxygen anion sublattice sublattice: O in a matrix of O2). These positive holes (or pholes for short) flow from the generation region into the surrounding rock. They effectively turn a rock into a giant battery. Under specific conditions, which cause the battery circuit to close, large phole currents can flow. Such currents lead to a variety of phenomena: (i) magnetic field variations and low to ultra-low frequency EM emissions, (ii) ionospheric perturbations over the epicentral region, (iii) air ionization at the ground-air interface and corona discharges with light and radio noise, and (iv) the emission of narrow-band infrared (IR) photons around 10 µm. These excess IR photons are the cause of the so-called thermal IR (TIR) anomaly. Often appearing days before major earth¬quakes, TIR anomalies have been seen from space by NASAs MODIS on TERRA and AQUA, by NOAAs AVHRR and GEOS, by Europes METEOSAT satellites. These various pre-earthquake signals can be used to design an earthquake early warning monitoring system, combining space assets and ground networks. Biography: Friedemann T. Freund is with the NASA Ames Research Center, Earth Science Division, Moffett Field, CA 94035-1000. He is Adjunct Professor, Department of Physics, San Jose State University, San Jose, and Principal Investigator at the Carl Sagan Center, SETI Institute, Mountain View, CA. Dr. Freund came to NASA Ames in 1985 after a 20-year career as professor in Germany at the universities of Göttingen and Cologne. His field of interest started with defects in crystals. This led him to questions related to the origin of Life and, as a spin-off, to the physics of pre-earthquake signals.