Synthesized investigation of seismotectonic vertical processes in the forearc coastal area of the plate convergence zone

板块辐合带弧前沿岸地区地震构造垂直过程综合研究

• 批准号: 16300293
• 负责人: MIYAUCHI Takahiro
• 金额: $ 9.73万
• 依托单位: Chiba University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 2004
• 资助国家: 日本
• 起止时间: 2004 至 2005
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-16300293/
• 关键词: plate convergence; non-seismic subsidence; coseismic uplift; Sanriku Coast; core-boring; radiocarbon dating; Holocene; unusual large earthquake; 機械ボーリング; 広域テフラ; 巨大地震履歴; 簡易掘削

We investigated the dynamic combination model of seismotecotonic uplift and non-seismotectonic subsidence, in order to understand tectonic processes originated from the plate convergence between the Pacific Plate and the Eurasia Plate, using Quaternary and geomorphological techniques. The obtained results are as follows.1. A succession of nine marine terraces is recognized, which were formed at interglacial stages at least after MIS21 (ca.800ka). Average uplift rate is estimated to be 0.2 to 0.4m/ka.2. At least Holocene marine terrace is recognizable at the height in 3 to 5 meters along the 120km long, northern coast of the Sanriku Coast. The emergence age is probably between 7ka and 5ka.3. Boring core data of 13 short drilling and 2 long drilling show the tectonic history : successive subsidence in rate of 7-9mm/yr between 8ka and 7ka, a possible episodic uplift producing the emergence of shallow marine topography around 2.9ka, and continuous subsidence with the rate of more than 1mm/yr after 2.9ka.4. Tidal records in the past 50 years at the five ports indicate that the Sanriku Coast is continuously subsiding. The subsidence rate ranges in 2 to 11mm/yr and tend to increase at the port closer to the Japan Trench.5. At least two co-seismic uplift events are practically estimated in the late Holocene, which likely occurred at 7-5ka and 3ka. This seismic scenario prevides that the recurrence time is about 3000 years and the uplift exceeds 10 meters.6. The extreme coseismic event of large uplift along the more than 100km long coast requires the extensive interplate faulting or the branching faulting from the plate boundary for the stress release by plate convergence. Such catastrophic faulting is probably associated with the M8-class earthquakes.

我们研究了地震观念隆起和非透视性沉降的动态组合模型，以了解使用Quaternary和Geomorphological Techniques的构造过程。获得的结果如下1。认识到九个海洋露台的一系列，至少在MIS21（Ca.800ka）之后，在冰间阶段形成。平均上升率估计为0.2至0.4m/ka.2。至少在Sanriku海岸的120公里长的120公里长的3到5米处，全新世海洋露台在3至5米处的高度都可以识别。出现年龄可能在7ka和5ka之间。3。 13个短钻孔和2个长钻孔的无聊核心数据显示了构造历史：8KA和7KA之间7-9mm/yr的连续沉降，这是一种可能的情节隆起，在2.9ka附近产生了浅海地形的出现，并且在2.9ka.4之后的较高的速度持续下降，速度持续下降，速度超过1mm/yr。在过去的50年中，潮汐记录在五个港口表明，桑里库海岸正在不断下降。沉降率在2至11mm/年的范围内趋向于在靠近日本沟渠的港口增加。5。在全新世晚期，至少估计了两个共同的隆起事件，可能发生在7-5ka和3ka。这种地震场景预示着复发时间约为3000年，而隆起超过10米。6。沿着超过100公里长的海岸沿着大型升高的极端Coseismic事件需要广泛的板间断层或板边界的分支断层，以通过平板收敛来释放压力。这种灾难性的断层可能与M8级地震有关。

项目成果

日本の地形3 東北

日本地形 3 东北

• 发表时间: 2005
• 作者: Suzuki;T.;小池一之
• 通讯作者: 小池一之

Earthquake Source Fault Beneath Tokyo

• DOI: 10.1126/science.1110489
• 发表时间: 2005-07
• 期刊: Science
• 影响因子: 56.9
• 作者: Hiroshi P. Sato;N. Hirata;K. Koketsu;D. Okaya;S. Abe;R. Kobayashi;M. Matsubara;T. Iwasaki;T. Ito;T. Ikawa;T. Kawanaka;K. Kasahara;S. Harder

日本の地形6 近畿・中国・四国

日本地形 6 近畿、中国、四国

• 发表时间: 2004
• 作者: Naruse;T.;成瀬 敏郎;太田陽子ほか(編)
• 通讯作者: 太田陽子ほか(編)

長井盆地西縁断層帯の第四紀後期活動性と地形発達

长井盆地西缘断裂带晚第四纪活动与地形发育

• 发表时间: 2004
• 期刊: 活断層研究 24
• 作者: 宮内崇裕;平柳幸彦;今泉俊文
• 通讯作者: 今泉俊文