极地研究

极地研究 ›› 2020, Vol. 32 ›› Issue (2): 195-201.DOI: 10.13679/j.jdyj.20190056

• 研究论文 • 上一篇    下一篇

Ewing型热流计的原位地温梯度与甲板热导率的精确匹配

许明珠1,2,张涛2,沈中延2,杨春国2,管清胜2,3,高金耀2   

  1. 1.山东科技大学, 山东 青岛 266590;
    2.自然资源部海底科学重点实验室, 自然资源部第二海洋研究所, 浙江 杭州 310012;
    3.南京大学, 江苏 南京 210023
  • 收稿日期:2019-10-10 修回日期:2019-12-16 出版日期:2020-06-30 发布日期:2020-06-30
  • 通讯作者: 张涛
  • 基金资助:

    国家自然科学基金(41576065)资助

Accurate matching of in-situ geothermal gradients from a Ewing-type heat flow meter with deck thermal conductivity

Xu Mingzhu1,2, Zhang Tao2, Shen Zhongyan2, Yang Chunguo2, Guan Qingsheng2,3, Gao Jinyao2   

  1. 1.Shandong University of Science and Technology, Qingdao 266590, China;
    2.Key Laboratory of Submarine Geosciences, Second Institue of Oceanography, Ministry of Natural Resources, Hangzhou 310012, China;
    3.Nanjing University, Nanjing 210023, China
  • Received:2019-10-10 Revised:2019-12-16 Online:2020-06-30 Published:2020-06-30

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摘要：

由于Ewing型热流计具有安全性和便捷性的优点, 其在恶劣环境下的热流测量作业中得到广泛应用。使用Ewing型热流计测量热流值时, 通过原位测量获取海底沉积物的地温梯度, 并在实验室中测量沉积物样品的热导率。由于桩效应的原因, 即取样器的插入深度和所取样品长度并不一致, 热导率和地温梯度测量位置难以精确匹配, 其造成的误差可达3.5 mW·m–2。基于同一站位不同深度上的热流值较为一致的原则, 设计了“最小标准偏差法”来确定Ewing型热流计作业的最优偏移量。针对中国第9次北极科学考察采集的12个站位数据分析表明, 经最小标准偏差法改正后, 同一站位各深度上热流值的标准偏差从8.4 mW·m–2减小到3.8 mW·m–2, 其变化幅值约为平均热流值的9%。

关键词: 北极, 热流, 热导率, 地温梯度, 最小标准偏差法

Abstract:

Ewing-type heat flow meters are widely used for heat flow measurements in harsh environments because of their safety and convenience. When using a Ewing-type heat flow meter, the geothermal gradient of seafloor sediments is obtained by in situ measurements while the thermal conductivity of sediment samples is measured in the laboratory. Due to the stake effect, the insertion depth of the sampler in situ is not always consistent with the length of a recovered sample, so it can be difficult to accurately match the measurement positions for thermal conductivity and geothermal gradients, leading to errors up to 3.5 mW·m–2. Based on the principle that heat flow values of the same station at different depths are relatively consistent, a minimum standard deviation method was designed in this study to determine the optimal deviation of Ewing heat flow meter operations. According to an analysis of data collected from 12 stations during China's ninth scientific Arctic expedition, the standard deviation of heat flow values at each depth of the same station decreased from 8.4 mW·m–2 to 3.8 mW·m–2 after the minimum standard deviation method was applied, which is a variation amplitude of about 9% of the average heat flow value.

Key words: Arctic, heat flow, thermal conductivity, geothermal gradient, minimum standard deviation