中国大陆地区热流数据的分布及其初步分析

THE DISTRIBUTION OF HEAT FLOW DATA IN THE CONTINENTAL AREA OF CHINA AND ITS PRELIMINARY STUDIES

本文首次系统地收集整理了观测资料比较齐全、国内公开发表的热流数据167个,并对之进行了初步分析。这些数据的地理分布还很不均匀,热流值变化范围为25—245mWm^(-2),多种平均方法得到的结果表明,中国大陆区域代表性热流值范围为61—68mWm^(-2)。作者所作的经纬度网格和条带统计还揭示,数据覆盖区内热流沿经、纬向的分布有明显的差异,纬向条带平均热流值看来具有波状起伏变化的规律。这一结果已经得到日本及其周围海域热流数据的初步印证,如果获得更广泛的证实,无疑具有深刻的地质和地球物理意义。

In this paper, 167 heat flow values with detailed measurememt data published so far in the continental area of China have been collected and used for statistic analyses. The geographical distribution of the heat flow sites in the area is quite uneven. The heat flow values vary from 25 to 245 mWm-2. Several methods have been employed to calculate the average heat flow. The results indicate that the representative heat flow for the continental area of China would lie in the range of 61 to 68 mWm-2.A new data analysis method has been developped in the present work. Firstly, mean heat flow values for 1°×1° longitude-latitude grids are calculated. Secondly, the mean grid values are used to average the mean values for the corresponding longitude and latitute strip, denoted as longitude and latitude heat flow separately. The results reveal that the difference between the. variations of longitude and latitude heat flow is significant. The variation of latitude heat flow seems to be characterized by a wave pattern. This phynomenon has been confirmed by the heat flow data from Japan and its surrounding oceanic area, which have also been reviewed in the same way. The wave pattern of latitude heat flow is shown not only in a stable wavelength of about 5°, but also in the well consistent wave cycles identified in the two areas. The author believes that the origin of the comparable latitude heat flow wave pattern is unlikely in the lithos-phere itself, but likely in the asthenosphere. Some geological and geophysical implications of the wave pattern have been briefly discussed.