the makran subduction zone in southeastern iran and southern pakistan is where the oceanic crust of the arabian plate (oman sea) is subducting beneath eurasia. compared to other subduction zones in the world, the makran subduction zone has some unusual features, including different seismicity patterns in its eastern and western parts. also, the quaternary volcanoes in the eastern part of makran...

This work employs high-resolution 3D thermomechanical numerical models of the incipient oceanic spreading to investigate nucleation and long-term evolution of ridge-transform spreading patterns. The Eulerian–Lagrangian visco-plastic model allows for large strains and accounts for plate cooling by both heat conduction and hydrothermal circulation as well as for partial melting of the asthenosphe...

aving considered the Earth’s formation in the last chapter, let’s now use the tools of geochemistry we acquired in the first eight chapters to consider how the Earth works. The Earth, unlike many of its neighbors, has evolved over its long history and it remains geologically active. Four and a half billion years later, it is very different place than it was first formed. Certainly one of the ma...

[1] Thermal records from boreholes in young oceanic crust, in which water is flowing up or down, are used to assess formation and borehole flow properties using three analytic equations that describe the transient thermal and barometric influence of downhole or uphole flow. We link these calculations with an iterative model and apply Markov chain Monte Carlo (MCMC) analysis to quantify ranges o...

[1] Double Wadati‐Benioff seismic zones (DSZ) with two parallel planes of seismicity separated by 15–30 km are a global feature of subduction zones in the 50–200 km depth range. Upper plane seismicity is generally attributed to dehydration of the oceanic crust but the origin of the lower seismicity plane is debated. Serpentine or hydrous‐phase dehydration embrittlement is a commonly advocated m...

We present a melt percolation model incorporating finite solid diffusion to provide a quantitative constraint on how melt migrates through the oceanic lower crust at fast-spreading ridge axes. The lower crustal, layered gabbro in the Oman ophiolite, which was formed at a fast-spreading ridge, shows correlated variations in primary mineral compositions with a vertical wavelength less than 100–20...

[1] We analyze short-period precursory energy to PP that can be observed in seismograms in the distance range from 95 to 105 to infer the behavior of subducted slabs beneath western Pacific subduction zones. PP is a P wave once reflected at the free surface between the source and receiver. Using high-resolution seismic array techniques, we analyze the incidence angle, timing, and azimuth of the...