Upper-mantle cross-section from California to Greenland
Item
Title (Dublin Core)
en-US
Upper-mantle cross-section from California to Greenland
Description (Dublin Core)
en-US
Pure-path upper-mantle models appropriate for tectonic, shield and old ocean have been recently presented by Grand and Helmberger. This was accomplished by modeling a rather restricted data set of S and SS triplication waveforms as well as the beginning portion of the Love waves. A much larger data set of S, SS and SSS, etc. (multibounce S-wave triplications) with a mixture of tectonic paths is available. In particular, events usually occur at tectonic margins and are recorded on stable continents. We present results of modeling these observations for laterally varying structure, essentially along a profile from California to Greenland. The models are allowed to be locally dipping with the lithosphere thickening with age at the expense of a dwindling low-velocity zone. Lateral variation does not appear to be required for depths greater than 400 km along this particular profile. The best-fitting model has a large increase in lithospheric thickness near the Rocky Mountain Front, roughly an increase of 75 km in thickness over a horizontal distance of 400 km or less. The low-velocity zone, with a velocity of 4.4 km/s, is replaced by a much faster upper 300 km with velocities near 4.7 km/s or a 7% overall increase. The one-way travel time jumps by roughly 4 s across this boundary, which compares reasonably well with the direct S residuals obtained from deep earthquake data although the latter data show large scatter.
ARK: https://n2t.net/ark:/88439/y069500
Permalink: https://geophysicsjournal.com/article/12
ARK: https://n2t.net/ark:/88439/y069500
Permalink: https://geophysicsjournal.com/article/12
Creator (Dublin Core)
Heimberger, D. V.
Engen, G.
Grand, S.
Subject (Dublin Core)
en-US
Upper mantle
en-US
S waves
en-US
Lateral variations
en-US
Synthetic seismograms
en-US
Solid Earth
Publisher (Dublin Core)
en-US
Journal of Geophysics
Date (Dublin Core)
1985-12-19
Type (Dublin Core)
info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
en-US
Peer-reviewed Article
Format (Dublin Core)
application/pdf
Identifier (Dublin Core)
https://journal.geophysicsjournal.com/JofG/article/view/12
Source (Dublin Core)
en-US
Journal of Geophysics; Vol 58 No 1 (1985): Journal of Geophysics; 92-100
2643-2986
2643-9271
Language (Dublin Core)
eng
Relation (Dublin Core)
https://journal.geophysicsjournal.com/JofG/article/view/12/6