澳客竞彩

鈥�The pursuit of truth and beauty is a sphere of activity in which we are permitted to remain children all our lives.鈥� Albert Einstein

Extreme environments like the Arctic and Antarctic are important scientific frontiers that help define the limits of Earth鈥檚 physical and biological processes. In particular extreme cold temperatures and the general lack of liquid water create a system where mechanical processes predominate and biological and chemical processes are confined to niche environments or are limited to brief periods when small amounts of water are available.听 The limiting nature of these environments reduce biophysical complexity thereby readily allowing the integrated investigation of climatic, geologic/geomorphic and biologic systems in a true Earth System Science framework. Arctic and Antarctic environments have many physical similarities, including seasonal patterns of daylight and temperature, the pervasive occurrence of glaciers, ice sheets and permafrost, and the strong environmental control on biological systems. However, the geographic position of the Antarctic continent, the vast extent of the East and West Antarctic Ice Sheets and the small isolated nature of ice-free areas (<2% of the landscape) tend to amplify many of the environmental extremes. The extreme cold and hyper-arid conditions of Antarctica and the high Arctic provide insight into conditions that may have existed on Mars 2-3 billion years ago (and to a lesser degree today) and thus are useful analogues in our search for evidence of Martian life.
听听听听听听听 My research centers upon the field investigation of water and ice in cold polar desert environments. My long-term goals are to understand and explain the hydrological and physical processes that shape and define cold dry landscapes and to identify niche environments in permafrost that are capable of harboring microbial life at or near the limit of its habitability.听 My research ranges from the field observation and measurement of natural processes at the landform and landscape scales to the microscopic examination of soil pores, ice crystals and intra crystalline brine films. My work incorporates a combination of traditional geologic, hydrogeologic, geomorphic and stratigraphic field approaches together with precision instrumentation to measure and map climatologic, hydrologic and geomorphic processes and patterns and microbial habitats.听 Laboratory and statistical analyses together with numerical modeling are undertaken to test and verify hypotheses.
听听听听听听听 Central to my research are: (a) the investigation of the dynamic interaction between water and cryotic ground, (b) the formation and degradation of surface and subsurface ice and (c) the interpretation of the environmental significance of landforms related to permafrost, ground ice and ground water. Over the last 6-7 years my science has evolved by focusing on progressively more complex questions and looking at progressively more extreme environments (the Arctic, Antarctica and Mars). The following are the projects in which I am currently active

Research Themes

My research group is currently involved in a series of projects focusing on various biophysical aspects of geocryology, including:

1) Ground ice in a changing climates

This research looks at the nature and distribution of ground ice and its role in landscape development. Initially this work looked at the Holocene evolution of high Arctic permafrost and ground ice (including its palaeoenvironmental significance) and the role of ground ice in contemporary landform development. My early research pioneered the application of petrographic techniques to the identification ground ice origin. Recently the focus of this research has expanded to include the potential impact of climate change on ice-rich landscapes. Climate change will present enormous challenges in polar regions. Assuming that global change has begun and GCM predictions are realistic, then the following questions pertaining to polar landscapes need to be addressed. First, 鈥淗ow sensitive are polar landscapes to climate change and how will ice-rich permafrost systems respond as climates warm?鈥� and second 鈥渁re polar landscapes already displaying the affects of climate change and how do we distinguish them from normal variation?鈥� With these questions in mind, the primary focus of my research is the detection and analysis of climate change impacts on (1) high latitude polar desert systems with an emphasis on permafrost dynamics and surface hydrology (study area Ellesmere Island) and (2) ice-rich coastal landscapes of the southern Beaufort Sea. The overarching goal of the proposed study is to determine how high Arctic permafrost will respond to climate change.
I began research on massive ground ice in the McMurdo Dry Valley area of Antarctica in 1997 and includes 2 field seasons in the McMurdo Dry Valleys. The first season I worked with the US Antarctic Program based at the LTER site on Lake Hoare in the Taylor Valley. Using ground penetrating radar I began mapping ground ice conditions in several of the dry valleys. In 2000 and 2003 I was part of the New Zealand Antarctic Program involved in a permafrost drilling project in the Allan Hills area. In addition to characterising ground ice type and distribution, I have also been investigating sublimation/desiccation processes in areas underlain by massive ice.