唐山井水温的同震变化及其物理解释

TELE-SEISMIC COSEISMIC WELL TEMPERATURE CHANGES AND THEIR INTERPRETATION

唐山市一口水井观测到多次同震水位振荡，以及伴之的高精度测量到的深部层水温变化．水温变化幅度与水位振荡幅度有关，水位幅度变化数厘米到一米，水温变化幅度为0．001℃～0.01℃，而且总是温度下降，震后一到数小时内水温恢复正常．我们进行了有限单元法模型计算，认为井水垂直振荡时搅动井水引起的弥散效应，是造成同震水温变化的主要原因，后续的热传导作用可以解释水温的复原过程．今后如果在不同深度同时进行高精度井水温度观测可以检验该模型.

Coseismic water level oscillation and correlated deep water temperature changes have been observed in a water well at Tangshan City by high sensitivity measurement. Amount of water temperature changes depend on ampli-tude of water level oscillation. Coseismic water temperatures always decrease as water level oscillates, drop of temperature ranges from 0. 001 ℃ to 0. 01℃ corresponding to amplitude of water level oscillation from several centimeters to about one meter. Temperatures usually recover one to several hours after the oscillation. We suggest that the temperature drop is produced by dispersive transfer of heat as the water oscillates, and follow-up thermal conduction makes temperature recovery. Our finite element calculations support quantitatively the idea. High ac-curacy measurements of water temperature at different depths in the future may test our interpretation.