The southernmost Ryukyu subduction zone may have a geodetically inferred M w 7.5 to 8.7 megathrust earthquake in shallow locked region, the fault. Paleoseismological evidence of historical earthquakes available from last 417 years indicates that only 1920 7.7 occurred within this magnitude range, near downdip end As slow slip events seismogenic trigger large earthquake, we investigate how first...

With the rapid development of global navigation satellite systems (GNSS) and their increasingly wide range applications in atmospheric science, total electron content (TEC) data are widely used theoretical study layer coupling related to seismicity. This detected analyzed pre-earthquake ionospheric anomalies (PEIA) by using TEC from Royal Observatory Belgium (ROB), coseismic disturbance (CID) w...

近年地震に先行して発生する電磁気学的な現象が 様々な周波数帯において報告されている [1]~[3].これ らは,観測方法によって (a)地殻内部から出てくる電 磁波(自然放射)を直接観測する方法と (b)既存電波 の伝搬異常として地震に伴う現象を検出する方法(電 波サウンディング)とに大別される.前者は,地震の 発生準備段階において地殻内部で応力変化等の原因で 自然放射が発生するとの考えに立脚している.後者は, 地震に関連するじょう乱が大気圏や電離圏に発生する との仮説に基づく.もし伝搬経路上の大気圏や電離層 に異常があれば,精密に制御されて送信されている既 存電波の観測点での振幅や位相に異常が出現するとの 考えによる.地震電磁気現象が目指す地震の短期予知 の観点から注目されているのが,(1) 地圏内現象であ る ULF放射と (2)電離層じょう乱観測の二つである. (1)は (a)...

Seismicity time properties of the Etna Volcano (Italy) are investigated through a systematic pattern recognition analysis. Mean Hypothesis Testing (MHT) has been applied to a long time database of instrumental data recorded from 1981 to 1996 to identify relevant correlation among seismic patterns, main seismogenic volumes and the eight flank eruptions occured in the same period. Time evolution ...

The south-eastern Gorny Altai is one of the most hazardous seismogenic area in north Central Asia. We present a synthesis field, 230Th-U geochronological, mineralogical and geochemical data collected on seven Quaternary travertines. All travertines occur within zones active faults that border Chuya Kurai intermontane basins. Travertine cement mainly comprises calcite (with minor amounts aragoni...

Taking into account recent studies on the tsunamigenic potential of strike-slip faults, it is concluded that there a need to reassess their near-source tsunami hazard and risk. One areas which needs reassessment Western Greece, especially Ionian Islands western coastal Peloponnese, where major seismogenic structures occur. In this context, an extensive review available literature conducted, inc...

This study presents the results of a landslide susceptibility analysis applied to Vrancea-Buzău seismogenic region in Carpathian Mountains, Romania. The target area is affected by large diversity processes. Slopes are made-up various types rocks, climatic conditions can be classified as wet, and seismically active one. All this contributes observed high hazard. paper analyses spatial component ...

The long-standing conflict between the predictions of elastic dislocation models and the observation that average coseismic slip increases with rupture length is resolved with application of a simple displacement-depth function and the assumption that the base of the seismogenic zone does not result from the onset of viscous relaxation but rather a transition to stable sliding in a medium that ...

Unique attributes in sequences of recurring, similar microearthquakes at Parkfield, California, provide a means for inferring slip rate at depth throughout the active fault surface from the time intervals between sequence events. Application of the method using an 11-year microseismicity record revealed systematic spatial and temporal changes in the slip rate that were synchronous with earthqua...