Drilling to investigate processes in active tectonics and magmatism

摘要

Coordinated drilling efforts are an important method to investigate activetectonics and magmatic processes related to faults and volcanoes. The USNational Science Foundation (NSF) recently sponsored a series of workshopsto define the nature of future continental drilling efforts. As part of thisseries, we convened a workshop to explore how continental scientificdrilling can be used to better understand active tectonic and magmaticprocesses. The workshop, held in Park City, Utah, in May 2013, was attendedby 41 investigators from seven countries. Participants were asked to definecompelling scientific justifications for examining problems that can beaddressed by coordinated programs of continental scientific drilling andrelated site investigations. They were also asked to evaluate a wide rangeof proposed drilling projects, based on white papers submitted prior to theworkshop.Participants working on faults and fault zone processes highlighted twooverarching topics with exciting potential for future scientific drillingresearch: (1) the seismic cycle and (2) the mechanics and architecture offault zones. Recommended projects target fundamental mechanical processes andcontrols on faulting, and range from induced earthquakes and earthquakeinitiation to investigations of detachment fault mechanics and fluid flow infault zones. Participants working on active volcanism identified five themes:the volcano eruption cycle; eruption sustainability, near-field stresses, andsystem recovery; eruption hazards; verification of geophysical models; andinteractions with other Earth systems. Recommended projects address problemsthat are transferrable to other volcanic systems, such as improved methodsfor identifying eruption history and constraining the rheological structureof shallow caldera regions. Participants working on chemical geodynamicsidentified four major themes: large igneous provinces (LIPs), ocean islands,continental hotspot tracks and rifts, and convergent plate margins(subduction zones).This workshop brought together a diverse group of scientists with a broadrange of scientific experience and interests. A particular strength was theinvolvement of both early-career scientists, who will initiate and carry outthese new research programs, and more senior researchers with many years ofexperience in scientific drilling and active tectonics research. Each of thethemes and questions outlined above has direct benefits to society, includingimproving hazard assessment, direct monitoring of active systems for earlywarning, renewable and non-renewable resource and energy exploitation, andpredicting the environmental impacts of natural hazards, emphasizing thecentral role that scientific drilling will play in future scientific andsocietal developments.