Details

Autor(en) / Beteiligte

• Yoshida, Kazuki
• Oyanagi, Ryosuke
• Kimura, Masao
• Plümper, Oliver
• Fukuyama, Mayuko
• Okamoto, Atsushi

Titel

Geological records of transient fluid drainage into the shallow mantle wedge

Ist Teil von

• Science advances, 2023-04, Vol.9 (14), p.eade6674-eade6674

Ort / Verlag

United States: American Association for the Advancement of Science

Erscheinungsjahr

2023

Quelle

EZB-FREE-00999 freely available EZB journals

Beschreibungen/Notizen

• Pore fluid pressure on subduction zone megathrusts is lowered by fluid drainage into the overlying plate, affecting subduction zone seismicity. However, the spatial and temporal scales of fluid flow through suprasubduction zones are poorly understood. We constrain the duration and velocity of fluid flow through a shallow mantle wedge based on the analyses of vein networks consisting of high-temperature serpentine in hydrated ultramafic rocks from the Oman ophiolite. On the basis of a diffusion model and the time-integrated fluid flux, we show that the channelized fluid flow was short-lived (2.1 × 10 to 1.1 × 10  years) and had a high fluid velocity (2.7 × 10 to 4.9 × 10  meters second ), which is close to the propagation velocities of seismic events in present-day subduction zones. Our results suggest that the drainage of fluid into the overlying plate occurs as episodic pulses, which may influence the recurrence of megathrust earthquakes.