Mantle Shear-Wave Velocity Structure Beneath the Hawaiian Hot Spot

• Published in: Science (American Association for the Advancement of Science) Vol. 326; no. 5958; pp. 1388 - 1390
• Main Authors: Wolfe, Cecily J, Solomon, Sean C, Laske, Gabi, Collins, John A, Detrick, Robert S, Orcutt, John A, Bercovici, David, Hauri, Erik H
• Format: Journal Article
• Language: English
• Published: Washington, DC American Association for the Advancement of Science 04.12.2009; The American Association for the Advancement of Science
• Subjects: Earth sciences; Earth, ocean, space; Earthquakes; Earthquakes, seismology; Exact sciences and technology; Geodynamics; Geophysics; Internal geophysics; Low speed; Lower mantle; Mantle; Plumes; Seismographs; Seismology; Solid-earth geophysics, tectonophysics, gravimetry; Transition zones; Upper mantle; Velocity; Hawaii; Polynesia; Oceania; United States > US; velocity structure; plumes; seismology; upper mantle; S-waves; deep-seated structures; seismic discontinuities; anomalies; high temperature; transition zones; depth; upwelling; seismometers; three-dimensional models; hot spots; mantle; SKS-waves; seismic waves
• ISSN: 0036-8075; 1095-9203
• DOI: 10.1126/science.1180165

Defining the mantle structure that lies beneath hot spots is important for revealing their depth of origin. Three-dimensional images of shear-wave velocity beneath the Hawaiian Islands, obtained from a network of sea-floor and land seismometers, show an upper-mantle low-velocity anomaly that is elongated in the direction of the island chain and surrounded by a parabola-shaped high-velocity anomaly. Low velocities continue downward to the mantle transition zone between 410 and 660 kilometers depth, a result that is in agreement with prior observations of transition-zone thinning. The inclusion of SKS observations extends the resolution downward to a depth of 1500 kilometers and reveals a several-hundred-kilometer-wide region of low velocities beneath and southeast of Hawaii. These images suggest that the Hawaiian hot spot is the result of an upwelling high-temperature plume from the lower mantle.