Sea level rise and land level change at Macquarie Island and deformation of the Australia-Pacific plate boundary zone

• Main Author: Burgette, RJ
• Format: Conference Object
• Language: English
• Published: School of Geography & Environmental Studies 2010
• Subjects: Engineering; Geomatic Engineering; Photogrammetry and Remote Sensing; Antarctic; Pacific; Antarc*; Macquarie Island
• Online Access: http://ecite.utas.edu.au/65545

Through the combination of rare historical sea level observations collected during Sir Douglas Mawsons 1911-1914 Australasian Antarctic Expedition, together with modern sea level data, space geodetic estimates of crustal displacement and modeling of coseismic and postseismic earthquake deformation, we present a contemporary analysis to constrain sea level and land level change over the twentieth century at Macquarie Island. We refine the source parameters of the Mw ~8.0 great earthquake of 23 December 2004 using estimates of coseismic displacements at regional GPS sites including HOB2 in Hobart. Modelling four years of post-2004.98 deformation constrains the oceanic upper mantle rheology. The 2000-2005 Macquarie Island GPS vertical velocity of -2.46 0.64 mm/y is explained by ongoing postseismic deformation from Macquarie Ridge great earthquakes of 1989 and 1924. The twentieth century observed relative sea level rise of +4.8 0.6 mm/y is consistent with an absolute sea level rise of +2.0 0.8 mm/y.