凱拉米科斯灣位於愛琴海東南方,靠近希臘及土耳其兩國交界處,為一沈積盆地,長度約100 公里,寬度約25 公里。此區域曾在1869 年及1941 年有大規模地震發生, 2004 年至2005 年間則經常發生中型地震(Mw »5.0-5.5)。反射震測研究調查結果顯示,本區域沈積層厚度大於2.5 公里,且在盆地南、北邊緣皆有幾組正斷層構造。持續觀測地震活動結果顯示其為一分散模式,且難以判斷地震活動所觸發的斷層為何條。本計畫將使用設置於土耳其境內之地震觀測網波形資料,進行重新定位。首先建立一維速度模型,以計算得出更精確的絕對定位,接著根據波形相關係數將走時進行分類,以計算更精準的相對定位。這有助於我們分辨哪些斷層的地震活動度較高,活動度較低的斷層則可能為將來發生中大型地震的區域。此外本計畫也將使用大規模地震的地震矩張量解,來檢驗該區的區域應力場。 The Gulf of Kerameikos (Gulf of Gökova in Turkish) is a sedimentary basin of approximately 25 km width and 100 km length and lies in the SE Aegean Sea near the border between Greece and Turkey. In the past it had been the site of large earthquakes (in 1869, 1941) and more recently in 2004-2005 several moderate events (Mw »5.0-5.5) have also occurred. Seismic reflection surveys conducted in this area previously revealed a thick sedimentary cover (»2.5 km) and imaged sets of normal faults at the northern and southern borders of the basin. Routinely determined seismicity shows a diffuse pattern and does not allow any assessment of which fault was activated during the latest unrest. Here we propose to combine waveform data from the Greek permanent seismic network along with data from stations in Turkey in order to improve these locations. First, a minimum 1D velocity model will be determined and will be used to obtain more accurate absolute locations. Subsequently, catalogue and differential traveltimes from waveform cross-correlation will be used for the purpose of deriving precise relative locations. This will help identify particular faults that have been seismically active and faults that show very little seismicity but could be the sites of future moderate to large earthquakes. Also, moment tensor solutions of the largest events will be used to check the regional stress field around the Gulf. 研究期間:10008 ~ 10107