Halpaap Felix, Rondenay Stéphane, Perrin Alexander, Goes Saskia, Ottemöller Lars, Austrheim Håkon, Shaw Robert, Eeken Thomas
Department of Earth Science, University of Bergen, Bergen, Norway.
Department of Earth Science and Engineering, Imperial College London, London, UK.
Sci Adv. 2019 Apr 3;5(4):eaav7369. doi: 10.1126/sciadv.aav7369. eCollection 2019 Apr.
Subducting plates release fluids as they plunge into Earth's mantle and occasionally rupture to produce intraslab earthquakes. It is debated whether fluids and earthquakes are directly related. By combining seismic observations and geodynamic models from western Greece, and comparing across other subduction zones, we find that earthquakes effectively track the flow of fluids from their slab source at >80 km depth to their sink at shallow (<40 km) depth. Between source and sink, the fluids flow updip under a sealed plate interface, facilitating intraslab earthquakes. In some locations, the seal breaks and fluids escape through vents into the mantle wedge, thereby reducing the fluid supply and seismicity updip in the slab. The vents themselves may represent nucleation sites for larger damaging earthquakes.
俯冲板块在俯冲入地球地幔时会释放流体，偶尔还会破裂引发板内地震。流体与地震是否直接相关存在争议。通过结合希腊西部的地震观测和地球动力学模型，并与其他俯冲带进行比较，我们发现地震有效地追踪了流体从深度大于80公里的板源到浅部（小于40公里）深度的汇的流动。在源和汇之间，流体在密封的板块界面下向上流动，促进了板内地震。在某些位置，密封破裂，流体通过通风口逸入地幔楔，从而减少了板内向上的流体供应和地震活动。通风口本身可能是更大破坏性地震的成核地点。
