青海地热台网温度漂移问题初步分析

通过对青海省15个流体观测井多年的温度数据进行年变趋势分析发现，数据长期性漂移具有普遍性。青海省地热台网有6个台（井）的年漂移量超过0.01 ℃/a，达到地热观测台网仪器要求上限。温度漂移与同井水位、当地气温变化没有关联性，而且漂移大小在空间上的分布也无规律可循，因此单纯从温度观测数据来讨论，无法判断这种年漂移是否与区域应力应变状态有关。研究玉树井多年温度数据趋势看出，玉树地震这一地壳活动导致该井的温度趋势发生变化，其温度上升速率出现明显拐点；同样，格尔木井也由于改变观测部位而出现温度趋势拐点，可见将温度漂移简单地归结于观测系统（仪器+传感器）有失偏颇。通过对比两种不同原理的温度计发现，单纯从测量原理上无法解决漂移问题。剔除漂移干扰的同时，漂移趋势自身也是一个值得研究的问题。

Analyses of Temperature Drift in Qinghai Geothermal Network

We found that observed-data drifts are common phenomena by analyzing the multi-year temperature variation trends of 15 fluid observation wells in Qinghai province. The drift of 6 wells exceed 0.01 ℃/a, which is the limitation in the observed network. There are no correlations between temperature drift, water level and air-temperature, and no rule is found in drift distribution. We cannot draw conclusions about the relations between temperature drift, regional stress and strain status. The infection point of temperature trends are generated by the earthquakes or changes the observed positions in Yushu and Geermu wells, which implies that the observation system (instrument & sensor) is not the unique reason for temperature drift. To reject the drift by changing the means of observation, by comparing two different thermometers, is not possible.