The tectonic development and erosion of the knox subglacial sedimentary basin, East Antarctica

Sedimentary basins beneath the East Antarctic Ice Sheet (EAIS) have immense potential to inform models of the tectonic evolution of East Antarctica and its ice-sheet. However, even basic characteristics such as thickness and extent are often unknown. Using airborne geophysical data, we resolve the tectonic architecture of the Knox Subglacial Sedimentary Basin in western Wilkes Land. In addition, we apply an erosion restoration model to reconstruct the original basin geometry for which we resolve geometry typical of a transtensional pull-apart basin. The tectonic architecture strongly indicates formation as a consequence of the rifting of India from East Gondwana from ca. 160-130 Ma, and we suggest a spatial link with the western Mentelle Basin offshore Western Australia. The erosion restoration model shows that erosion is confined within the rift margins, suggesting that rift structure has strongly influenced the evolution of the Denman and Scott ice streams

The terrain of health policy analysis in low and middle income countries: a review of published literature 1994–2007

This article provides the first ever review of literature analysing the health policy processes of low and middle income countries (LMICs). Based on a systematic search of published literature using two leading international databases, the article maps the terrain of work published between 1994 and 2007, in terms of policy topics, lines of inquiry and geographical base, as well as critically evaluating its strengths and weaknesses. The overall objective of the review is to provide a platform for the further development of this field of work

The intraplate character of supercontinent tectonics

For several decades geoscientists have recognised intraplate tectonic activity far from plate margins, both from modern and ancient examples. This apparent disconnect with the drivers of plate tectonics does not necessarily imply unconnected processes, but rather an uncertainty in understanding exactly how these systems operate. Are the driving forces derived locally or do they propagate from plate-margins? How do these forces interact with a complex tectonic inheritance to generate the observed tectonism? Furthermore, what novel approaches have been applied to understand these processes? Here we review the general literature and the contents of this special issue to develop some partial answers to these questions. Key observations include the critical importance of local lithospheric heterogeneities as a control on the mode of orogenesis, and also the role of locally derived forces from mantle upwelling or from depositing thick piles of magmatic or sedimentary rocks.

The sensitivity of the Antarctic Ice Sheet to a changing climate: Past, present and future

The Antarctic Ice Sheet (AIS) is out of equilibrium with the current anthropogenic‐enhanced climate forcing. Paleo‐environmental records and ice sheet models reveal that the AIS has been tightly coupled to the climate system during the past, and indicate the potential for accelerated and sustained Antarctic ice mass loss into the future. Modern observations by contrast suggest that the AIS has only just started to respond to climate change in recent decades. The maximum projected sea level contribution from Antarctica to 2100 has increased significantly since the IPCC 5th Assessment Report, although estimates continue to evolve with new observational and theoretical advances. This review brings together recent literature highlighting the progress made on the known processes and feedbacks that influence the stability of the AIS. Reducing the uncertainty in the magnitude and timing of the future sea‐level response to AIS change requires a multi‐disciplinary approach that integrates knowledge of the interactions between the ice sheet, solid Earth, atmosphere, and ocean systems, and across timescales of days to millennia. We start by reviewing the processes affecting AIS mass change, from atmospheric and oceanic processes acting on short timescales (days‐decades), through to ice processes acting on intermediate timescales (decades‐centuries) and the response to solid Earth interactions over longer timescales (decades‐millennia). We then review the evidence of AIS changes from the Pliocene to the present, and consider the projections of global sea‐level rise, and their consequences. We highlight priority research areas required to improve our understanding of the processes and feedbacks governing AIS change