Anomalously thin transition zone beneath the Gala¤pagos hotspot
Differential arrival times of P-to-S conversions at 410 and 660 km depth, measured from radial receiver functions, are used to determine the thickness of the mantle transition zone beneath the Gala¤pagos hotspot. For an area of approximately 700 km2 surrounding the Gala¤pagos archipelago, P660s3P410...
| Main Authors: | , |
|---|---|
| Other Authors: | |
| Format: | Text |
| Language: | English |
| Published: |
2003
|
| Subjects: | |
| Online Access: | http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.506.1854 http://pages.uoregon.edu/emilie/MyPapers/Hooft_GalapRF_EPSL_2003.pdf |
| Summary: | Differential arrival times of P-to-S conversions at 410 and 660 km depth, measured from radial receiver functions, are used to determine the thickness of the mantle transition zone beneath the Gala¤pagos hotspot. For an area of approximately 700 km2 surrounding the Gala¤pagos archipelago, P660s3P410s times are not significantly different from those for the Pacific Basin. In contrast, a subset of the Gala¤pagos data yields differential times indicating thinning of the mantle transition zone by 183 8 km within an area approximately 100 km in radius centered about 40 km southwest of the center of the island of Fernandina. This anomaly is consistent with an excess temperature of 1303 60 K within this volume of the transition zone, comparable to that inferred beneath the Iceland and Society hotspots. The most straightforward interpretation of this anomaly is that a mantle plume upwelling from depths greater than 410 km underlies the Gala¤pagos hotspot. |
|---|