Fig. 5: Time-evolution cartoon of Caribbean asthenosphere and dynamic topography.
From: Caribbean plate tilted and actively dragged eastwards by low-viscosity asthenospheric flow
Hotter asthenosphere sourced from the Galapagos plume flowed eastwards through the Central America slab window towards the Caribbean and produced an eastward dynamic tilt of the Earth’s surface. a At 8.5 Ma, prior to the slab window opening, the regional upper mantle was segmented by subducted slabs. b At ~8.5 Ma, the opening of the Panama slab window allowed eastward asthenospheric flows that were driven by pressure differences between the upwelling Galapagos plume to the west, and the subduction downwelling to the east. This geological event terminated the arc at the Panama land bridge and began the dynamic uplift of the Caribbean. c At present, the leading edge of hot asthenosphere imaged by full-waveform tomography25 has reached the Beata ridge. Eastward propagation of hot asthenosphere across the region produced time-transgressive back-arc magmatism within Central America that has a clear Galapagos isotopic signature26. Integration of these space-time constraints allows us to obtain the flow velocity of the Galapagos hot material which, together with the independent estimates of the driving pressure gradient and the thickness of the asthenosphere, constrain the absolute viscosity of the asthenosphere under the Caribbean to ~3*1018 Pa s.
