当前位置: X-MOL 学术Tectonophysics › 论文详情
Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)
A geometric model to estimate slip rates from terrace rotation above an offshore, listric thrust fault, Kaikōura, New Zealand
Tectonophysics ( IF 2.7 ) Pub Date : 2020-07-01 , DOI: 10.1016/j.tecto.2020.228460
Brendan Duffy

Abstract The Kaikōura Peninsula lies at the transition from subduction to continental collision at the southern end of the Hikurangi subduction system. This study uses a 2012 lidar survey over the Kaikōura Peninsula to re-map a flight of four uplifted Late Pleistocene marine terraces at high resolution. The lidar shows that the terraces are being progressively tilted landwards in a manner consistent with listric thrust faulting offshore. The fault, known as the Kaikōura Peninsula Fault, dips shallowly at c.30° to the northwest at depth and probably truncates the Seaward segment of the Hope Fault in the footwall of the Jordan Thrust. Geometric analysis of the tilt, using ages based on previous dating and a regional sea level curve, suggests that slip rates on the Kaikōura Peninsula Fault have ranged between 2.3 ± 1.5 mm/yr and 4.1 ± 1.3 mm/yr over the Late Pleistocene. The elevations of Late Holocene fringing beaches track regional sea level changes, apart from a departure indicating a single uplift event (penultimate earthquake) in the late 18th to earliest 19th century (1702–1838 CE), followed by uplift in the 2016 Kaikōura earthquake. The slip rate calculated from beach uplift, including the Kaikōura earthquake, is consistent with longer term rates. The accumulation of the slip over only c.220 years following >2000 years of quiescence suggests that the offshore thrust and associated faults exhibit clustered behavior, possibly as a result of keystone faulting.

中文翻译:

新西兰凯库拉近海列列式逆冲断层上方阶地旋转估计滑移率的几何模型

摘要 凯库拉半岛位于 Hikurangi 俯冲系南端从俯冲到大陆碰撞的过渡地带。这项研究使用了 2012 年凯库拉半岛上的激光雷达勘测,以高分辨率重新绘制了四个隆起的晚更新世海洋阶地的飞行图。激光雷达显示阶地正在以与离岸逆冲断层一致的方式逐渐向陆地倾斜。该断层被称为凯库拉半岛断层,在深度向西北方向倾斜约 30°,可能会截断约旦断续断层下盘的希望断层的向海部分。倾斜的几何分析,使用基于先前测年和区域海平面曲线的年龄,表明凯库拉半岛断层的滑动速率介于 2.3 ± 1.5 毫米/年和 4.1 ± 1 之间。晚更新世 3 毫米/年。全新世晚期边缘海滩的海拔跟踪区域海平面变化,除了表明 18 世纪末至 19 世纪最早(公元 1702 年至 1838 年)的单一隆起事件(倒数第二次地震)的偏离,随后在 2016 年凯库拉地震中隆起。根据海滩隆起计算的滑移率,包括凯库拉地震,与长期速率一致。在超过 2000 年的静止后仅约 220 年的滑移积累表明,近海逆冲断层和相关断层表现出聚集行为,可能是基石断层作用的结果。除了表明 18 世纪晚期至 19 世纪早期(公元 1702 年至 1838 年)的单一隆起事件(倒数第二次地震)的偏离,以及随后在 2016 年凯库拉地震中的隆起。根据海滩隆起计算的滑移率,包括凯库拉地震,与长期速率一致。在超过 2000 年的静止后仅约 220 年的滑移积累表明,近海逆冲断层和相关断层表现出聚集行为,可能是基石断层作用的结果。除了表明 18 世纪晚期至 19 世纪早期(公元 1702 年至 1838 年)的单一隆起事件(倒数第二次地震)的偏离,以及随后在 2016 年凯库拉地震中的隆起。根据海滩隆起计算的滑移率,包括凯库拉地震,与长期速率一致。在超过 2000 年的静止后仅约 220 年的滑移积累表明近海逆冲断层和相关断层表现出聚集行为,可能是基石断层作用的结果。
更新日期:2020-07-01
down
wechat
bug