美国加州大学Nicolas C. Barth研究组报道，新西兰阿尔卑斯地层古地震的破裂方向由弯曲滑动线所记录。这一研究成果发表在2024年10月7日出版的国际学术期刊《地质学》上。

据介绍，研究人员观察并进一步挖掘了，与新西兰约30mm/yr大陆转换板块边界的Alpine断层古地表破裂，相关的断裂面上的弯曲剖面线。动态破裂模型表明，这种曲率的几何形状提供了过去地震破裂方向的记录。

研究人员将工作集中在三个地点，这些地点跨越一个已知可变地阻止或允许过去地震通过的区域(“地震门”)，从而为断层时空丰富的古地震记录提供断裂方向限制。研究人员观察到在Hokuri Creek和Martyr River，主滑动面上和附近的凹凸弯曲滑动线，这些位置的东北部和西南部过去都发生过破裂。

在Martyr River，相关性表明最近的事件(推断与1717CE发生的事件有关)是从西南方向破裂的。研究结果强调，弯曲滑动线是一种有价值的古地震学新工具，可用于确定过去的破裂方向，适用于全球的地表破裂断层。

附：英文原文

Title: Rupture direction of paleoearthquakes on the Alpine Fault, New Zealand, as recorded by curved slickenlines

Author: Nicolas C. Barth, Jesse R. Kearse, Timothy A. Little, Russ J. Van Dissen

Issue&Volume: 2024-10-07

Abstract: We observed and further exhumed curved slickenlines on fault planes associated with paleo-surface rupture of the Alpine Fault, New Zealand’s ～30 mm/yr continental transform plate boundary. Dynamic rupture modeling indicates that the geometry of such curvature provides a record of past earthquake rupture directions. We focused our efforts on three sites that span a region known to variably halt or allow passage of past earthquakes (an “earthquake gate”) to contribute rupture direction constraints to the fault’s spatiotemporally rich paleoseismic record. At Hokuri Creek and Martyr River, we observed both convex-up and convex-down curved slickenlines on and adjacent to principal slip surfaces, indicating past ruptures from both the northeast and southwest of these locations. At Martyr River, relationships suggest that the most recent event (inferred to correlate to 1717 CE) ruptured from the southwest. Our results demonstrate the utility of curved slickenlines as a valuable new paleoseismological tool for determining past rupture directions, applicable to surface-rupturing faults globally.

DOI: 10.1130/G52543.1

Source: https://pubs.geoscienceworld.org/gsa/geology/article/doi/10.1130/G52543.1/649016/Rupture-direction-of-paleoearthquakes-on-the