A possible local anomaly in the 670-km discontinuity beneath Kerguelen

Details A possible local anomaly in the 670-km discontinuity beneath Kerguelen A possible local anomaly in the 670-km discontinuity beneath Kerguelen

Dec 1987

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1987pepi...49..294w&link_type=abstract

Physics of the Earth and Planetary Interiors, Volume 49, Issue 3-4, p. 294-303.

Physics

2

Scientific paper

The mapping of the 670-km discontinuity in regions of ascending or descending flows is of major interest for a better understanding of the nature of this discontinuity. In this paper, an attempt is made to investigate the properties of deep mantle discontinuities beneath the Kerguelen hot spot.
Anomalous P to S converted waves are observed for some earthquakes recorded at the Kerguelen long-period GEOSCOPE station; the characteristics of these phases are specified owing to a three-dimensional polarization analysis of the signals. A tilted discontinuity is able to explain the data; this discontinuity dips toward the northeast with at 20°. The depth at which the conversion takes place is ~ 880 km, assuming standard velocities in the upper mantle beneath Kerguelen, or 810 km if a hot upper mantle with a Poisson's ratio of 0.30-0.31 is present. However, the constraints given by the data are not strong enough to specify unambiguously this depth, a conversion at 600 km (or 550 km assuming a hot upper mantle) may alternatively be proposed. A strong velocity increase at the discontinuity is in each case necessary to explain the amplitude of the converted waves.
Geophysical arguments show that this tilted discontinuity must be a local feature; possible other mechanisms, such as wave focusing due to undulations of the discontinuity, may also be proposed.

Affiliated with

Also associated with

No associations

Rating

A possible local anomaly in the 670-km discontinuity beneath Kerguelen does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with A possible local anomaly in the 670-km discontinuity beneath Kerguelen, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and A possible local anomaly in the 670-km discontinuity beneath Kerguelen will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-905883