TY - JOUR
T1 - Polar wandering and the forced responses of a rotating, multilayered, viscoelastic planet.
AU - Sabadini, R.
AU - Yuen, D. A.
AU - Boschi, E.
PY - 1982
Y1 - 1982
N2 - Changes in the earth's rotation produced by the waxing and waning of large mobile ice sheets can be used to infer the viscosity of the mantle from a comparison with the recent secular polar drift as revealed in the International Latitude Service data and also in the estimates of the nontidal acceleration of the length of the day. We have developed by using an analytical approach a physical model of a rotating earth consisting of an elastic lithosphere, a viscoelastic mantle, and an inviscid core. Forcings from the two major ice sheets, Laurentide and Fennoscandia, have been considered. Sensitivity analysis of the parameters governing the external forcings, such as the length and the time of termination of the deglaciation phase, show in general that there exist two families of mean mantle viscosities, 0(1022P) and 0(1023P), which can match the data satisfactorily. However, we find it an improvement to incorporate some amount of shrinkage from the Antarctic ice sheet, obtaining simultaneously a better fit with the two rotational data sets to the lower viscosity solutions. Hence forcings from the southern hemisphere may be able to remove the ambiguity associated with the extraction of mantle viscosity from rotational data.-Authors
AB - Changes in the earth's rotation produced by the waxing and waning of large mobile ice sheets can be used to infer the viscosity of the mantle from a comparison with the recent secular polar drift as revealed in the International Latitude Service data and also in the estimates of the nontidal acceleration of the length of the day. We have developed by using an analytical approach a physical model of a rotating earth consisting of an elastic lithosphere, a viscoelastic mantle, and an inviscid core. Forcings from the two major ice sheets, Laurentide and Fennoscandia, have been considered. Sensitivity analysis of the parameters governing the external forcings, such as the length and the time of termination of the deglaciation phase, show in general that there exist two families of mean mantle viscosities, 0(1022P) and 0(1023P), which can match the data satisfactorily. However, we find it an improvement to incorporate some amount of shrinkage from the Antarctic ice sheet, obtaining simultaneously a better fit with the two rotational data sets to the lower viscosity solutions. Hence forcings from the southern hemisphere may be able to remove the ambiguity associated with the extraction of mantle viscosity from rotational data.-Authors
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U2 - 10.1029/JB087iB04p02885
DO - 10.1029/JB087iB04p02885
M3 - Article
AN - SCOPUS:0019912978
SN - 0148-0227
VL - 87
SP - 2885
EP - 2903
JO - Journal of Geophysical Research
JF - Journal of Geophysical Research
IS - B4
ER -