Seismic structure of the Iceland mantle plume

Article Abstract:

Oceanic hotspots are manifestations of plumes of hot, upwelling mantle material. However, the nature of these hotspots has remained a mystery. Although Iceland has been one of the most extensively researched hotspots in the world, the width and temperature of the plume have yet to be identified by previous seismological and geodynamic studies. Using relative travel times of body waves from teleseismic earthquakes, the three-dimensional velocity structure of the upper mantle beneath Iceland was analyzed. Results revealed a cylindrical zone of low P- and S-wave velocities that extends from 100 km to at least 400 km depth beneath central Iceland.

Hydrothermal vents

---

Seismic evidence for a fossil mantle plume beneath South America and implications for plate driving forces

Article Abstract:

A robust, nonlinear teleseismic travel-time inversion analysis indicates the existence of a fossil plume in the upper mantle below 200 km in Brazil. The data reveals that the lithosphere and upper mantle up to the depth of 500-600 km beneath South America have been in coupled motion for at least 130 million years. A study of P- and S-wave velocity structures indicates that the plume has a vertically cylindrical shape and the maximum difference between normal plume center is 1.5% in P- and 2% S-wave velocities. The history of plumes and the experimental procedure of seismic analysis are discussed.

Research, South America, Plumes (Fluid dynamics), Seismological research

---

Seismic evidence for a lower-mantle origin of the Iceland plume

Article Abstract:

It is generally accepted that Iceland is the manifestation of an upwelling mantle plume, but it is uncertain whether the plume originates from the lower mantle or from instabilities in the thermal boundary layer. Low seismic velocities are known to extend to at least 400 km depth below central Iceland. Lateral variations in the depths of compressional-to-shear wave conversions are reported at the top and bottom of the mantle transition zone below Iceland. The transition zone was found to be 20 km thinner than in the average Earth below central and southern Iceland.

Geophysical research

Similar abstracts:

• Abstracts: Seismic evidence for small-scale dynamics in the lowermost mantle at the root of the Hawaiian hotspot. Seismic detection of folded, subducted lithosphere at the core-mantle boundary
• Abstracts: Influence of the intertropical convergence zone on the East Asian monsoon. Nicholas Shackleton (1937-2006)
• Abstracts: Crystal structure of the sodium-potassium pump. Crystal structure of the plasma membrane proton pump. The structural basis of calcium transport by the calcium pump
• Abstracts: Structure of a DNA-bound Ultrabithorax-Extradenticle homeodomain complex. Nuclear import of the homeodomain protein extradenticle in response to Wg and Dpp signalling
• Abstracts: Release of both native and non-native proteins from a cis-only GroEL ternary complex. The crystal structure of the asymmetric GroEL-GroES-(APD)7 chaperonin complex

This website is not affiliated with document authors or copyright owners. This page is provided for informational purposes only. Unintentional errors are possible.