نتایج جستجو برای: ocean ridge basalt
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چکیده ندارد.
We simulate mantle flow, thermal structure, and melting processes beneath the ridge axis of South China Sea (SCS), combining nominally anhydrous fractional crystallization model, to study heterogeneity basin evolution. The model results are constrained by seismically determined crustal thickness major element composition fossil basalts. effects half-spreading rate, potential temperature, source...
Seismoacoustic evidence for volcanic activity on the ultraslow- spreading Gakkel Ridge, Arctic Ocean
[1] In 1999, a swarm of earthquakes and a lava flow signaled a volcanic eruption at the eastern end of Gakkel Ridge, the slowest spreading ridge worldwide. In summer 2001, the multidisciplinary Arctic Mid-Ocean Ridge Expedition studied these ridge processes which are unusual at ultraslow spreading rates. As part of these studies, we examined the microearthquake activity of the ridge with seismo...
We report the surface exploration by the lunar rover Yutu that landed on the young lava flow in the northeastern part of the Mare Imbrium, which is the largest basin on the nearside of the Moon and is filled with several basalt units estimated to date from 3.5 to 2.0 Ga. The onboard lunar penetrating radar conducted a 114-m-long profile, which measured a thickness of ∼5 m of the lunar regolith ...
The temperature and composition of Earth's mantle control fundamental planetary properties, including the vigor of mantle convection and the depths of the ocean basins. Seismic wave velocities, ocean ridge depths, and the composition of mid-ocean ridge basalts can all be used to determine variations in mantle temperature and composition, yet are typically considered in isolation. We show that c...
Variations of oxygen isotope ratios in arc-related lavas can constrain trace-element enrichment in a mantle source being fluxed by addition the contributions of subducted crustal igneous rocks, sediments, and of aqueous fluid. Comparison of this model with observed variations fluids to the sub-arc mantle. We have measured oxygen isotope in the geochemistry of lavas from the Vanuatu–Fiji–New Cal...
High latitude ocean gateway changes are thought to play a key role in Cenozoic climate evolution. However, the underlying ocean dynamics are poorly understood. Here we use a fully coupled atmosphere-ocean model to investigate the effect of ocean gateway formation that is associated with the subsidence of the Greenland-Scotland Ridge. We find a threshold in sill depth (∼50 m) that is linked to t...
The coupled 100,000 year variations in ice volume, temperature, and atmospheric CO2 during the late Pleistocene are generally considered to arise from a combination of orbital forcing, ice dynamics, and ocean circulation. Also previously argued is that changes in glaciation influence atmospheric CO2 concentrations through modifying subaerial volcanic eruptions and CO2 emissions. Building on evi...
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