A reanalysis and reinterpretation of geodetic and geological evidence of glacial-isostatic adjustment in the Churchill region, Hudson Bay

• Other Authors: Wolf, Detlef
• Language: English
• Published: Geoforschungszentrum 2004
• Subjects: 550 520; 16,13; ggo geo; Canada; Hudson; Hudson Bay
• Online Access: http://webdoc.sub.gwdg.de/ebook/serien/tm-v/STR/0411.pdf; http://www.gfz-potsdam.de/bib/pub/str0411/0411.htm; http://deposit.ddb.de/cgi-bin/dokserv?idn=972813977; http://nbn-resolving.de/urn/resolver.pl?urn=urn:nbn:de:kobv:b103-04111

We review the historical, geological, tide-gauge, GPS and gravimetric evidence advanced in favour of or against continuing land uplift around Hudson Bay, Canada. After this, we reanalyse the tide-gauge and GPS data for Churchill using longer time series than those available to previous investigators. The dependence of the mean rate of relative sea-level change obtained on the length and mid-epoch of the observation interval considered is investigated by means of the newly developed linear-trend analysis diagram. For studying the shorter-period variability of the tide-gauge record, the continuous-wavelet transform is used. The mean rate of land uplift obtained from GPS is based on a new analysis using IGS solutions of GFZ. Furthermore, sea-level indicators from the Churchill region representing the relative sea-level history during the past 8000 a are included. Finally, the four types of observable are jointly inverted in terms of mantle viscosity. The optimum values are 3×10^20 Pa s and 1.6 × 10^22 Pa s for the upper- and lower-mantle viscosities, respectively.