11:00 〜 13:00
[SSS07-P18] DSeis Report 4: M5.5 Orkney地震の発生場周辺の３次元速度場の較正―３D反射法データとDD再決定されたM5.5地震の余震活動と苦鉄質/超苦鉄質貫入体との比較
キーワード：地震活動の筋、苦鉄質・超苦鉄質シル・ダイク複合体、地震発生場掘削、鉱山地質情報、2014 M5.5 Orkney 地震
We could calibrate the 3D velocity structure for the 3D seismic reflection cube (Figure left) which include most part of the aftershocks for the 2014 Orkeny M5.5 earthquake. Drastic change in the dolomite velocity from < 6 km/s to ~ 6.5 km/s resulted in the significant vertically downwad shift in the seismic reflection image by ~ 300m.
Before this calibration we couldn't discuss the spatial relationship between the sills and reflectors, both of which dip 20 degrees toward the south east, and the aftershock streaks as shown in Figure (right). The modified vertical depth section much better spatially correlates with the streaks of the aftershocks. We wil detail the outcomes in our presentation.
This report is related to the other ICDP DSeis reports, which include an FY2021 activity overview (M-GI32), the dense stress measurements (S-SS07), material analysis for the core recovered from altered ultramafic dyke that hosted the aftershocks of the M5.5 earthquake (S-CG46).
The DSeis team consists of seismologists, geologists, geomicrobiologisits, rock mechanists, mining engineers from Japan, South Africa USA, Switzerland, Germany, India, and Australia. The DSeis project is build on JST-JICA SATREPS project and Kakenhi (21224012) and is supported by ICDP, JSPS Core-to-Core Program, Ritsumeikan University, MEXT 2nd Earthquake and Volcano Hazard Reduction Research, and Kochi Core Center.
Before this calibration we couldn't discuss the spatial relationship between the sills and reflectors, both of which dip 20 degrees toward the south east, and the aftershock streaks as shown in Figure (right). The modified vertical depth section much better spatially correlates with the streaks of the aftershocks. We wil detail the outcomes in our presentation.
This report is related to the other ICDP DSeis reports, which include an FY2021 activity overview (M-GI32), the dense stress measurements (S-SS07), material analysis for the core recovered from altered ultramafic dyke that hosted the aftershocks of the M5.5 earthquake (S-CG46).
The DSeis team consists of seismologists, geologists, geomicrobiologisits, rock mechanists, mining engineers from Japan, South Africa USA, Switzerland, Germany, India, and Australia. The DSeis project is build on JST-JICA SATREPS project and Kakenhi (21224012) and is supported by ICDP, JSPS Core-to-Core Program, Ritsumeikan University, MEXT 2nd Earthquake and Volcano Hazard Reduction Research, and Kochi Core Center.