Subduction zone metamorphic pathway for deep carbon cycling: II. Evidence from HP/UHP metabasaltic rocks and ophicarbonates

Deep-Focus Repeating Earthquakes in the Tonga–Fiji Subduction Zone

Abstract Deep-focus earthquakes in the Tonga–Fiji subduction zone make up greater than 66% of the globally recorded deep seismicity. The high number of deep-focus seismicity in this active subduction zone allows us to search for deep-focus similar earthquake pairs and repeating earthquakes. We compile a waveform dataset for deep earthquakes with magnitude above 4.7 occurring in the Tonga–Fiji–K...

Climate, carbon cycling, and deep-ocean ecosystems.

Climate variation affects surface ocean processes and the production of organic carbon, which ultimately comprises the primary food supply to the deep-sea ecosystems that occupy approximately 60% of the Earth's surface. Warming trends in atmospheric and upper ocean temperatures, attributed to anthropogenic influence, have occurred over the past four decades. Changes in upper ocean temperature i...

Groundwater in Sedimentary, Metamorphic and Volcanic Rocks

Deep structure of Japan subduction zone as derived from local, regional, and teleseismic events

We have determined a detailed three-dimensional P wave velocity structure of the Japan subduction zone to 500-km depth by inverting local, regional, and teleseismic data simultaneously. We used 45,318 P wave arrivals from 1241 shallow and deep earthquakes which occurred in and around the Japan Islands. The arrival times are recorded by the Japan University Seismic Network which covers the entir...

Slow oxygen diffusion rates in igneous zircons from metamorphic rocks

Empirical tests of oxygen exchange rate in zircon crystals from amphiboliteand granulite-facies metamorphic rocks of the Grenville Province demonstrate preservation of igneous dO through protracted igneous and metamorphic histories, forming the basis of quantitative estimates of diffusion rate. Granitic orthogneisses, which cooled slowly after granulite-facies metamorphism, show no consistent r...