Post-rifting stress relaxation at the divergent plate boundary in northeast Iceland
Links
- More information: Publisher Index Page (via DOI)
- Open Access Version: External Repository
- Download citation as: RIS | Dublin Core
Abstract
Interaction of the elastic lithosphere with the underlying anelastic asthenosphere causes strain to propagate along the Earth's surface in a diffusion-like manner following tectonism at plate boundaries. This process transfers stress between adjacent tectonic segments and influences the temporal tectonic pattern along a plate boundary. Observations of such strain transients have been rare, and have hitherto been confined to strike-slip and underthrusting plate boundaries1. Here we report the observation of a strain transient at the divergent (spreading) plate boundary in Iceland. A Global Positioning System survey undertaken a decade after an episode of dyke intrusion accompanying several metres of crustal spreading reveals a spatially varying strain field with the expected diffusion-pulse shape and an amplitude three times greater than the 5.7 cm that would be expected from the average spreading rate2. A simple one-dimensional model with a thin elastic layer overlying a viscous layer fits the data well and yields a stress diffusivity of 1.1 á±0.3 m2s−1. Combined with struc-tural information from magnetotelluric measurements, this implies a viscosity of 0.3−2 × 1019 Pa s—a value comparable to that derived for Iceland from post-glacial rebound23, but low compared with estimates for mantle viscosity obtained elsewhere3.
Study Area
| Publication type | Article |
|---|---|
| Publication Subtype | Journal Article |
| Title | Post-rifting stress relaxation at the divergent plate boundary in northeast Iceland |
| Series title | Nature |
| DOI | 10.1038/358488a0 |
| Volume | 358 |
| Issue | 6386 |
| Year Published | 1992 |
| Language | English |
| Publisher | Springer Nature |
| Description | 3 p. |
| First page | 488 |
| Last page | 490 |
| Country | Iceland |