Texas A&M University, United States

Long-term temperature measurements using miniaturized temperature loggers (MTLs) were performed in Ocean Drilling Program Holes 1253A and 1255A across the Middle America Trench off the Nicoya Peninsula, Costa Rica. All three recovered loggers, which were retrieved fully functional, provided high-resolution temperature records. These records cover a time span of approximately 2 yr and were sampled at an interval of 17 min. There are a number of signals in the temperature data that are most likely caused by hydrologic events. These events are also present in the pressure data recorded by Circulation Obviation Retrofit Kit (CORK)-IIs that are installed in these boreholes. Moreover, the temperature data are important input parameters for calculating pumping rates of the OsmoSamplers, within which the MTLs were integrated. Therefore, the MTL temperature records combined with the CORK-II pressure measurements and the data from the OsmoSampler fluid samples allow the investigation of subduction zone hydrologic processes.