Marlborough Fault System, South Island, New Zealand

Collaborative Research: Towards an Understanding of the Collective Behavior of Regional Fault Networks: The Marlborough Fault System, New Zealand (James F. Dolan, PI, University of Southern California). This project was a collaborative effort between PI Dolan (USC) and co-I Ed Rhodes (UCLA) and New Zealand collaborators Russ Van Dissen and Rob Langridge of GNS Science. The survey area consists of a total of 254 km of fault-parallel, predominantly ~1.2-km-wide swaths along parts of the four main right-lateral strike-slip faults that comprise the Marlborough Fault System, in the northwestern portion of New Zealand's South Island. The five fault segments surveyed include sections of the eastern and western parts of the Clarence fault, the central part of the Awatere fault, the central part of the Wairau fault, and part of the eastern (Conway) segment of the Hope fault. These lidar data facilitated detailed analysis of fault offsets along the four main MFS faults, as well as mapping of small displacements that have occurred in recent earthquakes on Marlborough faults in unprecedented detail, the geomorphic development and evolution of fluvial terraces crossing these faults, and the progressive geomorphic manifestation of off-fault deformation with increasing fault displacement. The data were analyzed by the PIs, our New Zealand collaborators, and three graduate students at USC (Robert Zinke, Alexandra Hatem, and Jessica Grenader), and one graduate student at UCLA (Chris McGuire [supervised by Co-I Ed Rhodes]); their results will form major parts of their graduate theses. The lidar data were collected by U.S. National Center for Airborne Laser Mapping (NCALM) personnel using an aircraft and flight personnel subcontracted from New Zealand Aerial Mapping. The data were collected with a combination of NCALM's Optech GEMINI sensor (operated at a laser pulse frequency of 125 kHz in multi-pulse mode, at a nominal height above ground of 1400 m) and NZAM's Optech 3100A sensor (operated at a laser pulse frequency of 70-100 kHz at various heights depending on terrain). Shot density is &ge; 12 shots/m². The lidar data were utilized in our studies of the incremental slip-rate record of the four main Marlborough faults. The lidar data also provided a means of mapping small displacements that have occurred in recent earthquakes on Marlborough faults in unprecedented detail, the sedimentological development and geomorphic evolution of fluvial terraces crossing these faults, and the progressive geomorphic manifestation of off-fault deformation with increasing fault displacement (see Zinke et al., 2015 Geology for a discussion of this latter topic [doi:10.1130/G37065.1]).<p><br>Publications associated with this dataset can be found at <a href=\"http://calm.geo.berkeley.edu/ncalm/dtc.html\" target=\"_blank\">NCALM's Data Tracking Center</a></p>

合作研究：解析区域断层网络的集体行为——新西兰马尔堡断层系统（James F. Dolan，首席研究员，南加州大学）。本项目由首席研究员Dolan（南加州大学，University of Southern California, USC）与联合首席研究员Ed Rhodes（加州大学洛杉矶分校，University of California, Los Angeles, UCLA），以及新西兰地质科学研究所（GNS Science）的Russ Van Dissen和Rob Langridge合作完成。

本次调查区域位于新西兰南岛西北部，覆盖构成马尔堡断层系统（Marlborough Fault System，简称MFS）的4条主要右旋走滑断层沿线，总长254千米的断层平行条带，条带平均宽度约1.2千米。此次调查涵盖5个断层段：克拉伦斯断层东西两段、阿瓦特雷断层中段、怀劳断层中段，以及霍普断层东部（康威）段。

此次机载激光雷达（Light Detection and Ranging，LiDAR）数据为马尔堡断层系统4条主断层的断层位移精细化分析提供了有力支撑，以空前的细节精度刻画了马尔堡断层近期地震中产生的微小位移，解析了横穿断层的河流阶地的地貌发育与演化过程，以及随断层位移增加而逐渐显现的断层外变形的地貌表现。

数据由首席研究员团队、新西兰合作方，以及南加州大学的3名研究生（Robert Zinke、Alexandra Hatem与Jessica Grenader）、加州大学洛杉矶分校的1名研究生（Chris McGuire，由联合首席研究员Ed Rhodes指导）共同完成分析，相关成果将成为他们学位论文的核心组成部分。

机载激光雷达数据由美国国家机载激光测绘中心（National Center for Airborne Laser Mapping, NCALM）工作人员操作采集，其飞行团队由新西兰航空测绘公司（New Zealand Aerial Mapping, NZAM）分包。数据采集使用了两套传感器：NCALM的Optech GEMINI传感器（多脉冲模式下激光脉冲频率125 kHz，标称地面飞行高度1400米），以及NZAM的Optech 3100A传感器（根据地形调整飞行高度，激光脉冲频率70~100 kHz）。本次采集的点云密度≥12点/平方米。

该激光雷达数据被用于研究马尔堡4条主断层的渐进式滑动速率记录，同时也为精细刻画马尔堡断层近期地震的微小位移、横穿断层河流阶地的沉积学发育与地貌演化，以及随断层位移增加的断层外变形的渐进地貌表现提供了关键支撑（相关后一主题的讨论详见Zinke等人2015年发表于《Geology》的研究，DOI:10.1130/G37065.1）。

<p><br>本数据集关联的公开成果可访问<a href="http://calm.geo.berkeley.edu/ncalm/dtc.html" target="_blank">NCALM数据跟踪中心</a></p>