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

正在寻求资金购买声发射系统，使我们能够研究深源地震在深部地幔压力-温度条件下的机制。据推测，深源地震是由深部地幔矿物相变时伴随晶体结构变化而发生的断层作用引起的，深源地震在实验上受到的关注相对较少。这些微地震实验研究中的挑战在于高压-高温样品室的结构，而高压-温度样品室在体积上必然受到限制。我们新的3000吨多砧压机将为我们从实验矿物物理角度理解地球深部过程开辟新的研究方向，因为我们的样本量很大。我们将在代表地幔过渡带(410-520公里深)条件的压力和温度下，使用新的多锤装置对地幔矿物(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。这将需要多个超声波传声器，这些传声器分布在相对于样品的不同位置。通过比较微地震阵列中不同麦克风的传播时间，可以获得特定声发射事件的震源位置。比以往任何一次此类实验都要大的样本将使关于矿物声源产生的位置和时间演变的空间分辨率更好。

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.