Abstract

A geodynamic model of the modern Earth is constructed based on the SMEAN 2 global seismic tomography model with an emphasis on the Arctic region. For a spherical Earth model, a solution of the Stokes equation for a viscous fluid was obtained based on seismic tomography data using the CitcomS code. The resulting distributions of temperature anomalies and velocity fields of mantle flows explain the main features of the modern geodynamics of the Arctic region. The temperature difference in the subcrustal mantle between the relatively “cold” western Arctic shelf (Barents and Kara seas) and the “warmer” eastern Arctic shelf (from the Laptev Sea to the Bering Strait) reaches 100 degrees, which correlates with the observed intense methane emission from the shallow shelf of the Eastern Arctic caused by permafrost degradation and destruction of gas hydrates against the background of elevated environmental temperatures. The greenhouse effect of methane in the atmosphere, in turn, contributes to climate warming in the Arctic. The region of Iceland and eastern part of Greenland, under the influence of the mantle upwelling, is characterized by a hot subcrustal mantle and increased heat flow at the surface, causing instability and melting of the Greenland ice sheet from below.

中文翻译：

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地球全球地球动力学模型及其在北极地区的应用

摘要

现代地球的地球动力学模型是基于 SMEAN 2 全球地震层析成像模型构建的，重点关注北极地区。对于球形地球模型，使用 CitcomS 代码根据地震层析成像数据获得了粘性流体斯托克斯方程的解。由此产生的温度异常和地幔流速度场的分布解释了北极地区现代地球动力学的主要特征。相对“寒冷”的北极西部陆架（巴伦支海和喀拉海）和“温暖”的北极东部陆架（从拉普捷夫海到白令海峡）之间的地幔温差达到100度，这与观测到的强烈环境温度升高背景下，永久冻土退化和天然气水合物破坏导致北极东部浅陆架甲烷排放。大气中甲烷的温室效应反过来又导致北极气候变暖。冰岛地区和格陵兰岛东部地区，在地幔上升流的影响下，其特点是地壳下地幔温度很高，地表热流增加，导致格陵兰冰盖从下方不稳定并融化。