An Investigation of the Effects of Cold, Thick Lithosphere on Deformation of Slowly Slipping Mega-Transforms; The Andrew Bain Transform, SWIR

在这笔资金的资助下，一组美国科学家将加入一艘意大利机遇号船，研究西南印度洋山脊的安德鲁·贝恩变换域(ABTD)，并将在巡航后的研究中进行合作。ABTD范围广，活动转换断裂由一系列短的中继型伸展盆地组成，连接一条长而直的南股和一条较短的直的北股。意大利R/V探险探险队获得的新的地质和地球物理数据(多波束测深/侧扫、重力、磁学和多通道地震)，与PIS以前收集的数据相结合，将全面了解ABTD的地形构造结构和物理结构。这些新数据可以用来解决以下问题：1.主要转换位移带在ABTD内的什么位置？2.是什么力量导致了连接ABTD内较长的南北转换断层的伸展中继盆地的形成？3.能否建立一个理论/数值模型来解释ABTD和其他缓慢滑动的巨型转换的地形构造特征？4.安德鲁·贝恩转换的形态和结构与大型大陆转换相比如何，这种相似性是否对大陆大型转换的变形提供了附加限制？

Under this funding, a group of US scientists will join an Italian ship of opportunity to study the Andrew Bain Transform Domain (ABTD) of the Southwest Indian Ridge, and will collaborate in the post-cruise research. The ABTD is broad and the active transform fault consists of a series of short relay-type extensional basins connecting a long straight southern strand and a shorter straight northern strand. The new geological and geophysical data (multibeam bathymetry/sidescan, gravity, magnetics and multi-channel seismics) from the expedition on the Italian R/V Explora , when combined with data collected by the PIs previously, will provide a complete view of the morphotectonic fabric and physical structure of the ABTD. These new data can be used to address the following questions; 1. Where does the Principal Transform Displacement Zone lie within the ABTD? 2. What forces led to the formation of the extensional relay basins that connect the longer southern and northern transform faults within the ABTD? 3. Can a theoretical/numerical model be developed to explain the observed morphotectonic signature of the ABTD and other slow-slipping mega-transforms? 4. How does the morphology and structure of the Andrew Bain Transform compare to large continental transforms, and do the similarities provide addition constraints on the deformation of continental mega-transforms?