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|magnitude = 5.6 and 5.7 Mw |depth = 9.6 km and 10.4 km |location = 〔(【引用サイトリンク】title=Comments for the Significant Earthquake )〕 |countries affected = United States (Santa Rosa) |intensity = VII (''Very Strong'') |aftershocks = Yes |casualties = 1 }} At 04:56 and 06:19 UTC on October 2, 1969 (21:56 and 23:19 PDT October 1), a pair of earthquakes of magnitude 5.6 and 5.7, respectively, struck the city of Santa Rosa, California, killing one person and damaging buildings. The maximum felt intensity for the two events was VII (''Very Strong'') and VIII (''Severe'') respectively on the Mercalli intensity scale. The $8.35 million cost of the earthquakes went mostly to replace buildings damaged beyond repair. There were at least 200 aftershocks after the initial pair of earthquakes. At the time they were the largest earthquakes to affect the northern San Francisco Bay Area since the 1906 San Francisco earthquake.〔 ==Tectonic setting== The current tectonics of northern California are mainly controlled by the San Andreas Fault system, the zone of dextral strike-slip faulting that accommodates displacement between the North American Plate and the Pacific Plate along this transform boundary. In addition to the San Andreas Fault itself there are numerous other sub-parallel dextral strike-slip faults that take up some of the plate boundary motion distributed through a zone more than 100 km wide.〔 The 1969 earthquakes and most of their aftershocks occurred along the Healdsburg Fault, which lies between the Maacama Fault and the Rodgers Creek Fault, linked to them by right step-overs. These faults may form a continuation of the Hayward Fault Zone north of San Francisco Bay. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「1969 Santa Rosa earthquakes」の詳細全文を読む スポンサード リンク
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