Air and shipborne magnetic surveys of the Antarctic into the 21st century

Abstract

The Antarctic geomagnetics' community remains very active in crustal anomaly mapping. More than 1.5 million line-km of new air-and shipborne data have been acquired over the past decade by the international community in Antarctica. These new data together with surveys that previously were not in the public domain significantly upgrade the ADMAP compilation. Aeromagnetic flights over East Antarctica have been concentrated in the Transantarctic Mountains, the Prince Charles Mountains-Lambert Glacier area, and western Dronning Maud Land (DML)-Coats Land. Additionally, surveys were conducted over Lake Vostok and the western part of Marie Byrd Land by the US Support Office for Aerogeophysical Research projects and over the Amundsen Sea Embayment during the austral summer of 2004/2005 by a collaborative US/UK aerogeophysical campaign. New aeromagnetic data over the Gamburtsev Subglacial Mountains (120,000 line-km), acquired within the IPY Antarctica's Gamburtsev Province project reveal fundamental geologic features beneath the East Antarctic Ice sheet critical to understanding Precambrian continental growth processes. Roughly 100,000 line-km of magnetic data obtained within the International Collaboration for Exploration of the Cryosphere through Aerogeophysical Profiling promises to shed light on subglacial lithology and identify crustal boundaries for the central Antarctic Plate. Since the 1996/97 season, the Alfred Wegener Institute has collected 90,000 km of aeromagnetic data along a 1200 km long segment of the East Antarctic coast over western DML. Recent cruises by Australian, German, Japanese, Russian, British, and American researchers have contributed to long-standing studies of the Antarctic continental margin. Along the continental margin of East Antarctica west of Maud Rise to the George V Coast of Victoria Land, the Russian Polar Marine Geological Research Expedition and Geoscience Australia obtained 80,000 and 20,000 line-km, respectively, of integrated seismic, gravity and magnetic data. Additionally, US expeditions collected 128,000 line-km of shipborne magnetic data in the Ross Sea sector.

New Antarctic gravity anomaly grid for enhanced geodetic and geophysical studies in Antarctica

“…Gravity anomalies can aid studies of subduction and terrane accretion processes [Ferraccioli et al, 2002[Ferraccioli et al, , 2006 and intraplate basin formation [Ferraccioli et al, 2009]. The availability of new terrestrial gravity anomaly grids for Antarctica will also augment current international efforts to compile almost two million line kilometers of recent magnetic anomaly data for the continent [Golynsky et al, 2013] and together with these data, will provide a window on Antarctic subglacial geology and tectonic evolution [Jokat et al, 2003;Riedel and Jokat, 2007;Ferraccioli et al, 2009;Aitken et al, 2014].…”

Holocene glacial activity in Barilari Bay, west Antarctic Peninsula, tracked by magnetic mineral assemblages: Linking ice, ocean, and atmosphere

“…The general subice geology can be inferred from the regional tectonic history [ Elliot , ; Burton‐Johnson and Riley , ] and implications for detrital magnetic mineralogy can be inferred from comparison of bedrock magnetic susceptibilities with aeromagnetic geophysical surveys [ Wendt et al ., ]. Magnetic anomalies from geophysical surveys indicate Barilari Bay sits on the boundary of two geologic terranes: the Mesozoic magmatic arc dominated Central Domain to the west and the Trinity Peninsula Group dominated Eastern Domain, composed of the mostly sedimentary and metasedimentary rocks of the deformed Gondwana continental margin, to the east [ Ferraccioli et al ., ; Golynsky et al ., ].…”

Utility of Slepian basis functions for modeling near-surface and satellite magnetic anomalies of the Australian lithosphere

“…However, the Slepian coefficients also can be used to update the global spherical harmonic coefficients, and thus, Slepian modeling can be efficient for updating global spherical harmonic models with new data. This approach will be particularly effective for updating global spherical harmonic models for new satellite observations such as from the Swarm mission (e.g., Thébault et al 2016;Olsen et al 2016) and new aeromagnetic surveys such as in the Antarctic (e.g., Golynsky et al 2013;von Frese et al 2008), the oceans, and other large unsurveyed regions of the Earth.…”