Gravity Measurements to Bound Instrusive Density at Long Valley Caldera

Zumberge位于加利福尼亚州的长谷，火山口是一个正在经历重大变形的复活火山穹顶的所在地。重力对观测的质量和坐标都很敏感；重复测量将提供有关这些参数变化的信息。这些观测将限制地下质量变化的速度，并可能有助于危险评估和预警。当局将使用绝对重力仪观测沥原少数地点的重力情况。高精度相对重力仪与众多其他站点的连接将扩大空间覆盖范围。通过尽可能在不透水岩石上选择地点，以及通过分析美国地质勘探局收集的水文数据，将把地下水位变化的影响降至最低。将生成结合重力和GPS数据的模型；从这些模型中，人们可以推断潜在变形动力学的细节。这个项目是与斯坦福大学研究人员保罗·西格尔和莫里齐奥·巴塔格里亚(他们是由美国能源部资助的)合作完成的。

9902799Zumberge The Long Valley, California, caldera is the site of a resurgent volcanic dome which is experiencing significant deformation. Gravity is sensitive to both mass and coordinates of the observations; repeated measurements will provide information on changes in those parameters. These observations will bound the rates of subsurface mass change and may also assist in hazard assessment and warning. Gravity at a small number of sites in Long Valley will be observed with an absolute gravimeter. High precision relative gravimeter ties to numerous other sites will expand the spatial coverage. Water table variation effects will be minimized by site selection on impermeable rock where possible, and by analysis of hydrological data collected by the USGS. Models incorporating the gravity with GPS data will be generated; from these, one can infer details of the underlying deformation dynamics. This project is a collaboration with Stanford University researchers Paul Segall and Maurizio Battaglia (who are funded under a grant from DOE).