GEA - Geodynamic Evolution of East Antarctica

Country / Region: East Antarctica / Dronning Maud Land

Begin of project: November 1, 2010

Status of project: July 30, 2019

Sør Rondane Mountains in eastern Dronning Maud Land, East Antarctica Source: BGR

The GEA programme developed from several precursor projects that have been carried out in different regions of East Antarctica since the 1990s. These were in particular GEOMAUD, PCMEGA and GIGAGAP and the AGAP project, which represented one of the flagship programmes of the International Polar Year (IPY) 2007-09. GEA bundles these geological and geophysical research and future projects under a new umbrella, which now summarizes all research activities of the BGR in greater East Antarctica.

Objectives of the GEA programme

The aim of GEA is to investigate the crustal evolution and crustal structure of East Antarctica as well as the formation of today's continent representing an isolated land mass at the South Pole. In particular, BGR studies geodynamic processes such as the formation and fragmentation of the supercontinent Gondwana and its predecessor Rodinia, the evolution of mountain belts at the margin and in the interior of Antarctica, the development of rift systems, and the evolution of present day landforms resulting from the interaction of various processes and factors, e.g. tectonics, lithology and climate.

Field studies in Sør Rondane during GEA II expedition Source: BGR

During Earth's history, Antarctica was not always an isolated continent, as we know it today. It was at a central position within the supercontinent Rodinia, which formed at 1.1 to 1.0 billion years ago and began to disintegrate between 800 and 700 million years ago. Antarctica also formed the centrepiece of the supercontinent Gondwana, which united all of today's southern continents plus India. Gondwana fromed by several continental collisions and accretionary processes between 650 to 500 million years ago. These resulted in the closure of an oceanic realm and the rise of a major mountain range comparable in size with the Himalaya Mountains today. Remains of this ancient mountain range is preserved today in East Africa and Dronning Maud Land, East Antarctica, and is known as the East African-Antarctic Orogen. It can be speculated that a relict of the collision and accretion processes (a so-called suture zone) can be found within Dronning Maud Land. The location of this suture and its character has been one major target of the GEA programme.

Polar 6 aircraft shortly bevor takeoff for a survey flight Source: BGR

The break-up of the Gondwana supercontinent - indicated by massive flood basalt eruptions around 180 million years ago - led to the present-day isolated location of Antarctica near the South Pole and the development of new ocean current systems, responsible for today’s climate conditions. Due to its position in the vicinity of the Karoo-Maud-Plume (a fixed upwelling of Earth’s hot mantle, like for example under the Hawaiian island chain) between Antarctica, Africa/Madagascr and India/Sri Lanka, Dronning Maud Land is of fundamental importance to understand the break-up history of Gondwana, the opening of the South Atlantic Ocean and the formation of the current plate configuration.

The dynamics of the uppermost crustal levels are investigated by structural-geological, petrological, geochemical and geo-/thermochronological methods. These studies help to better understand the geological evolution and ancient paleogeographic position of Dronning Maud Land within Gondwana, the break-up of this huge landmass and the formation of passive continental margins, as well as the long-term landscape evolution and climatic development in this region.

Only about 2% of exposed rocks of the Antarctic continent is accessible for direct geoscientific research, the remaining 98% are covered by several kilometres of thick ice. This fact highlights the importance of geophysical investigations to study the Polar Regions. Since the beginning of its polar research activities, BGR has established a combined geological-geophysical approach to explore the Antarctic continent. The airborne measurement of e.g. the magnetic rock properties, of rocks that are not directly accessible (due to ice or water coverage) became a central instrument of BGR’s investigations. For this purpose, the research aircraft of the AWI "Polar 5" (for GEA I) and "Polar 6" (for GEA II to V) were used as measurement platform.

Project contributions:

• Expedition GEA I (2010/2011)
• Expedition GEA II (2011/2012)
• Expedition GEA III to GEA IV (2012/13 und 2014/15)
• Expedition GEA V (2016/17)

Partner:

The GEA programme has been carried out in close cooperation with the Alfred-Wegener-Institute, Helmholtz Centre for Polar and Marine Research (AWI) and the National Antarctic Programmes of Belgium, Australia, Norway, South Africa and Japan as well as several universities.

• Alfred-Wegener-Institute, Helmholtz Centre for Polar and Marine Research
• Norwegian Polar Institute (NPI)
• Belgian Antarctic Research Expeditions
• University of Bergen
• University of Bremen
• University of Johannesburg
• University of Tübingen
• Curtin Univ. Perth
• University of Oslo
• University of Granada
• University of Münster
• University of Frankfurt/M.
• TU Bergakademie Freiberg
• FU Berlin
• Japanese Institute for Polar Research (NIPR)