Acoustic emission system for micro-seismicity studies at high pressures and temperatures

正在寻求资金购买一个声发射系统，使我们能够研究在深地幔压力-温度条件下发生深源地震的机制。深源地震被认为是由断层作用引起的，当深部地幔矿物经历伴随着晶体结构变化的相变时，深源地震受到的实验关注相对较少。这些微地震实验研究的挑战在于高压-温度样品池的配置，这必然是在体积上的限制。我们新的3000吨多砧压机将开辟新的研究方向，因为大样本量，我们试图从实验矿物物理学的角度来了解地球深部过程。我们将使用新的多砧装置在代表地幔过渡带（410-520公里深度）条件的压力和温度下对地幔矿物（橄榄石、蛇纹石和相关的致密含水镁硅酸盐矿物）进行现场声发射测量。这将需要分布在相对于样品的不同位置的多个超声波麦克风。通过比较微地震阵列中不同麦克风的行进时间，可以获得特定声发射事件的源位置。比以往任何此类实验中更大的样本将允许更好的空间分辨率关于声源生成矿物的位置和时间演变。

Funds are sought to purchase an acoustic emission system that will allow us to study the mechanisms of deep focus earthquakes at deep mantle pressure-temperature conditions. Postulated to be caused by faulting that occurs when deep mantle minerals undergo phase transformations accompanied by changes in crystal structure, deep focus earthquakes have received relatively little experimental attention. The challenges in these micro-seismic experimental studies lie in the configuration of the high pressure-temperature sample cell which is necessarily restricted in volume. Our new 3000 ton multi-anvil press will open up new research directions in our attempts to understand deep earth processes from an experimental mineral physics perspective because of the large sample size. We will perform in-situ acoustic emission measurements on mantle minerals (olivine, serpentine and associated dense hydrous magnesium silicate minerals) using the new multi-anvil apparatus at pressures and temperatures representative of the conditions located in the Mantle Transition Zone (410-520 km depth). This will require multiple ultrasonic microphones that are distributed in different positions relative to the sample. By comparing travel times of distinct microphones in a micro-seismic array, it is possible to obtain the source location of a particular acoustic emission event. Larger samples than in any previous experiment of this kind will allow for better spatial resolution concerning the location and time evolution of acoustic source generation of minerals.