David PÍŠA Study of electromagnetic emissions recorded by the DEMETER satellite Abstract : This thesis presents results based on wave measurements performed by the DEMETER space- craft. This French spacecraft was operating between 2004 and 2010 at the altitude of ∼660 km. We focus on measurements of the electromagnetic waves and plasma density in the vicinity of imminent earthquakes. In the first part, we present a study of plasma density variations in the vicinity of a very powerful earthquake in Chile (Mw 8.8) which occurred on February 27, 2010. Data recorded before the main shock along orbits close to the future epicenter showed increasing plasma den- sities. A statistical analysis using 4 years of data to monitor density variations under similar conditions has been performed. This study shows that a large increase of the plasma density is very uncommon at this location. In the second part, a statistical study (∼6.5 years) of variations of VLF wave intensity is shown. We have analyzed all available data measured close (in time and space) to large earth- quakes (M≥5). Data related to more than 12000 earthquakes have been compared with an unperturbed background distribution. We confirm the previously reported results of a statis- tically significant decrease of the wave intensity at frequencies of about...
| Identifer | oai:union.ndltd.org:nusl.cz/oai:invenio.nusl.cz:326915 |
| Date | January 2012 |
| Creators | Píša, David |
| Contributors | Santolík, Ondřej, Shklyar, David R., Souček, Jan |
| Source Sets | Czech ETDs |
| Language | French |
| Detected Language | English |
| Type | info:eu-repo/semantics/doctoralThesis |
| Rights | info:eu-repo/semantics/restrictedAccess |
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