Prospecting for hotspot roots

Article Abstract:

Seismologists Helmberger and colleagues and Russel and colleagues claimed to have identified the roots of Iceland and Hawaiian hotspots at the core-mantle boundary, 2,900 km below the Earth's surface. Helmberger and colleagues have shown that the ultra-low velocity zone can be detected below Iceland, which may reflect the hot source of the Iceland mantle plume. Russell and colleagues analyzed ScS and S phases to identify an area of lateral gradients in the lower mantle, suggesting the source region of the Hawaiian hotspot.

Observations, Plumes (Fluid dynamics), Magma

---

Mineralogy and dynamics of a pyrolite lower mantle

Article Abstract:

The Earth's upper and lower mantles are thought to be broadly similar in composition, consisting of a mixture of minerals called pyrolite. New diamond-anvil cell experiments simulate depths of 1,500 and 2,900 km at the lower mantle and show that pyrolite consists of only three types: magnesiowustite, magnesian-silicate perovskite and calcium-silicate perovskite. It is suggested that the lithology of subducting slabs in the lower mantle will make them buoyant before thermal equilibrium is attained.

Earth, Structure

---

The elusive coldfinger

Article Abstract:

In the Earth sciences, a concept explaining some features of continents, is that they are cooler and less dense than the mantle surrounding them. However Li and colleagues report that the features of the continental coldfinger are absent, following studies in continental North America. They measured seismic waves and monitored changes corresponding to mineralogical transitions in the mantle. The mantle transitions created echoes of the main seismic waves.

Similar abstracts:

• Abstracts: Caring for companions. An angel with a wagging tail. The bird fancy
• Abstracts: Competition for royalty in bees. Beetle larvae cooperate to mimic bees. A sudden absence of bees
• Abstracts: Sean Day. The heart of Harbinger. Linda Hatfield
• Abstracts: Influence of motion signals on the perceived position of spatial pattern. Infants listen for more phonetic detail in speech perception than in word-learning tasks
• Abstracts: Global and fine information coded by single neurons in the temporal visual cortex. Visual input evokes transient and strong shunting inhibition in visual cortical neurons

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