Abrupt change in greenhouse gases emission rate as a possible genetic model of TIR anomalies observed from satellite in Earthquake active regions

摘要

Several studies have been performed, in the past 25 years, on the basis of Thermal Infrared (TIR) satellite imagery, which suggest the existence of a relation between TIR anomalies and earthquake preparatory phenomena. Among the various genetic models, the increase of green-house gas (such as CO_2, CH_4,etc) emission rates, have been suggested to explain the appearance of anomalous TIR signal transients in some relation with the place and time of earthquake occurrence. In this paper the idea that an enhanced greenhouse gas emission can not be excluded among the main causes of TIR anomalies observed close to earthquake occurrence is supported by different independent observations:1) The increase of Earth's TIR radiation to be expected as a consequence of an increase (from 2 to 20 times its normal level) of atmospheric CO_2 concentration has been evaluated by using MODTRAN Radiative Transfer code. A significant (more than 10 K in brightness temperature) TIR signal increase is to be expected as soon as local CO_2 concentration becomes 3 times higher.2) TIR anomalies observed by applying the well known Robust Satellite Technique (RST) to long historical series of Meteosat TIR observations performed over seismic areas characterized by different prevailing degassing activity: in areas dominated by diffusing gases heavier than air (as COj) anomalous TIR patterns seem to clearly follow morphological lineaments (e.g. tectonic faults); in areas dominated by diffusing gases lighter than air (as CH_4) anomalous TTR patterns flood wide areas, diffusing around with less marked correlation with morphological lineaments.