Groundwaterflowvelocitymeasurementsinasinkholeatthe Weeig Island Strategic Petroleum Reserve Facility, Louisiana

In 1992, a sinkhole was discovered above a Strategic Petroleum Reserve storage facility at Weeks<br>Island, Louisiana. The oil is stored in an old salt mine located within a salt dome. In order to assess the<br>hydrologic significance of the sinkhole, an In Situ Permeable Flow Sensor was deployed within a sandfilled<br>conduit in the salt dome directly beneath the sinkhole. The flow sensor is a recently developed<br>instrument which uses a thermal perturbation technique to measure the m.agnitude and direction of the full<br>3-dimensional groundwater flow velocity vector in saturated, permeable materials. The flow sensor<br>measured substantial groundwater flow directed vertically downward into the salt dome. The data<br>obtained with the flow sensor provided critical evidence which was instrumental in assessing the<br>significance of the sinkhole in terms of the integrity of the oil storage facility.