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Dr. Joanne Johnson - Profile

Research Interests

From 2015-2019 I am Principal Investigator on a NERC standard grant (NE/K012088/1) entitled:

"Reconstructing millennial-scale ice sheet change in the western Amundsen Sea Embayment, Antarctica, using high-precision exposure dating"

My Co-Investigators are Steve Roberts (BAS) and Dylan Rood (Imperial). The project also involves Joerg Schaefer (Lamont Doherty Earth Observatory, Columbia University), David Pollard (Pennsylvania State University), and Pippa Whitehouse (Durham) as Project Partners, and the Scottish Universities Environmental Research Centre. Steve Roberts and I will be undertaking fieldwork around Mt Murphy and the Kohler Range in November 2015.

I am also working on:

  • Determining Quaternary glacial history of the Lassiter Coast, Antarctica - with Joerg Schaefer (Columbia, USA) and Bob Finkel (Berkeley, USA)
  • Comminution dating boundary conditions: A study of (234U/238U) disequilibrium along the Antarctic Peninsula -  with Adi Torfstein (Hebrew University of Jerusalem, Israel), funded by Lamont Doherty Climate Center grant ($8000)
  • Antarctic Peninsula exhumation and landscape development investigated by low-temperature detrital thermochronometry (NSF grant 1246484) - with Greg Balco, David Shuster and Matt Fox (Berkeley, USA)
     

From 2009-2013, I my work focused on samples from the Hudson Mountains, which lie adjacent to Pine Island Glacier. This built on research of the QWAD project (see below). We obtained a high-resolution record of thinning of a tributary of Pine Island Glacier, which showed rapid thinning in the early Holocene (8 kyrs ago). This research was published in 2013 in Science (see Johnson et al., 2013).

 

From 2005-2009, I worked in the QWAD (Quaternary West Antarctic Deglaciation project, within the GRADES (Glacial Retreat in Antarctica and Deglaciation of the Earth System) project. I used cosmogenic surface exposure dating to construct a preliminary age versus elevation record for nunataks near the Pine Island Glacier (e.g. the Hudson Mountains). I visited the Hudson Mountains in 2006, as part of the Alfred Wegener Institute cruise ANT-XXIII/4 on the RV Polarstern. Please see Johnson et al. 2008 (Geology) for the results of this work. There is also a good article in Nature Reports Climate Change describing my work in the Amundsen Sea Embayment at

http://www.nature.com/climate/2008/0804/full/climate.2008.30.html

 

From August 2002 to April 2005, I worked on a project focusing on the origin and palaeoenvironmental implications of authigenic alteration minerals in volcaniclastic rocks from James Ross Island (Northern Antarctic Peninsula). The aim was to understand the relationship of alteration to the composition of porewaters present during eruption, and to determine whether the chemical composition of alteration products (such as zeolites and clay minerals) reflects the alteration environment. I undertook Antarctic fieldwork on James Ross Island in January 2003 and January-March 2004. This formed part of the LCHAIS (Late Cenozoic History of the Antarctic Ice Sheet) project, within the GIANTS (Global Interactions of the ANTarctic Ice Sheet) programme (which ran from 2000-2005).

For my PhD, I studied the geochemistry of a suite of alkaline lavas from the Vitim Volcanic Field in Siberia. This lies ~ 200 km east of Lake Baikal, in one of the world's major continental rift zones. My research involved using geochemical characteristics of these lavas to constrain the composition and thickness of the lithosphere in the Baikal Rift Zone, and to improve our understanding of the melting regime beneath the region during the Cenozoic.