Depth Extent of the Lau Back-Arc Spreading Center and Its Relation to Subduction Processes

See allHide authors and affiliations

Science  10 Oct 1997:
Vol. 278, Issue 5336, pp. 254-257
DOI: 10.1126/science.278.5336.254

You are currently viewing the abstract.

View Full Text

Log in to view the full text

Log in through your institution

Log in through your institution


Seismic tomography and wave form inversion revealed that very slow velocity anomalies (5 to 7 percent) beneath the active Lau spreading center extend to 100-kilometer depth and are connected to moderately slow anomalies (2 to 4 percent) in the mantle wedge to 400-kilometer depth. These results indicate that geodynamic systems associated with back-arc spreading are related to deep processes, such as the convective circulation in the mantle wedge and deep dehydration reactions in the subducting slab. The slow regions associated with the Tonga arc and the Lau back arc are separated at shallow levels but merge at depths greater than 100 kilometers, suggesting that slab components of back-arc magmas occur through mixing at these depths.

  • * To whom correspondence should be addressed. E-mail: dzhao{at}

View Full Text

Stay Connected to Science