Decrease of intensity of ELF/VLF waves observed in the upper ionosphere close to earthquakes: A statistical study

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F68378289%3A_____%2F09%3A00330763" target="_blank" >RIV/68378289:_____/09:00330763 - isvavai.cz</a>

Výsledek na webu

—

DOI - Digital Object Identifier

—

Jazyk výsledku

angličtina

Název v původním jazyce

Decrease of intensity of ELF/VLF waves observed in the upper ionosphere close to earthquakes: A statistical study

Popis výsledku v původním jazyce

We present results of a systematic study of intensity of VLF electromagnetic waves observed by the DEMETER spacecraft in the upper ionosphere (altitude 700 km). We focus on the detailed analysis of the previously reported decrease of wave intensity shortly before the main shock during the nighttime. Using a larger set of data (more than 3.5 years of measurements) and a newly developed data processing method, we confirm the existence of a very small but statistically significant decrease of wave intensity 0?4 hours before the time of the main shock at frequencies of about 1.7 kHz. It is shown that the decrease does not occur directly above the earthquake epicenter but is shifted about 2 degrees in the westward direction. Moreover, it is demonstrated that the decrease occurs more often close to shallower earthquakes and close to earthquakes with larger magnitudes, as it is "intuitively" expected, representing an additional proof of validity of the obtained results.

Název v anglickém jazyce

Decrease of intensity of ELF/VLF waves observed in the upper ionosphere close to earthquakes: A statistical study

Popis výsledku anglicky

We present results of a systematic study of intensity of VLF electromagnetic waves observed by the DEMETER spacecraft in the upper ionosphere (altitude 700 km). We focus on the detailed analysis of the previously reported decrease of wave intensity shortly before the main shock during the nighttime. Using a larger set of data (more than 3.5 years of measurements) and a newly developed data processing method, we confirm the existence of a very small but statistically significant decrease of wave intensity 0?4 hours before the time of the main shock at frequencies of about 1.7 kHz. It is shown that the decrease does not occur directly above the earthquake epicenter but is shifted about 2 degrees in the westward direction. Moreover, it is demonstrated that the decrease occurs more often close to shallower earthquakes and close to earthquakes with larger magnitudes, as it is "intuitively" expected, representing an additional proof of validity of the obtained results.

Druh

J_x - Nezařazeno - Článek v odborném periodiku (Jimp, Jsc a Jost)

CEP obor

BL - Fyzika plasmatu a výboje v plynech

OECD FORD obor

—

Projekt

<a href="/cs/project/GA205%2F06%2F1267" target="_blank" >GA205/06/1267: Vazby nízkofrekvenčními vlnami mezi atmosférou, ionosférou a vnitřní magnetosférou Země</a><br>

Návaznosti

Z - Vyzkumny zamer (s odkazem do CEZ)

Rok uplatnění

2009

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Journal of Geophysical Research

ISSN

0148-0227

e-ISSN

—

Svazek periodika

114

Číslo periodika v rámci svazku

-

Stát vydavatele periodika

US - Spojené státy americké

Počet stran výsledku

10

Strana od-do

—

Kód UT WoS článku

000264866000003

EID výsledku v databázi Scopus

—