Lower mantle lateral heterogeneity beneath the caribbean Sea.

Seismic wave reflections from Earth's core recorded at seismic arrays in North America from events in the Caribbean Islands, Venezuela, and the Mid-Atlantic Ridge have observed slownesses more than 64 percent greater than predicted by the IASPEI91 standard Earth model. P waves turning in the lowermost mantle beneath the same region also have anomalous slowness. The slowness anomalies are not accompanied by significant travel time residuals and appear to be caused by lateral inhomogeneities in the velocity structure of the lower mantle.