Lakes are often a source of recreation such as fishing, boating and swimming and interior Alaska is no different. Lakes in interior Alaska have also have been used by ancient peoples for thousands of years but now these lakes are currently experiencing changes in water level and water quality. Dr. Mat Wooller and colleagues are working to better understand how lakes respond to environmental changes by piecing together how previous lake levels and water quality were related. They are using lake sediment cores to look back over the past 10,000 years of water levels, local ecology and water quality were related to give us a vision of how interior Alaskan lakes will change in the future.
Lakes in interior Alaska, such as Quartz Lake, are focal points for recreational use including sport fishing. Many of these lakes have been on the landscape for thousands of years and were also used by ancient people that populated interior Alaska thousands of years ago. However, many of these lakes are currently experiencing changes in lake level and chemistry associated with hydrological changes. Efforts to successfully assess how future climate change will affect levels of lakes in interior Alaska are faced with a major challenge, which is that there are limited long-term records of how lake levels have changed in the past and how these changes have responded to environmental changes. Fortunately there are sediments in lakes, like Quartz Lake, that have been laid down over thousands of years since the lakes first appeared on the landscape. A core down through these sediments provides a time-line of a lake’s history. Evidence of how the lakes changed over this time-line is preserved in the layers of mud. When multiple cores are taken from sites on a transect across a lake, going from the deepest part of a lake to the shallow edge of a lake, they can be dated and lined up to show how a lake filled over time and also show when lake levels decreased. This is an approach that has been successfully used to construct coarse temporal resolution records of lake level fluctuations in some lakes in interior Alaska (e.g., Harding Lake and Birch Lake). However, the logistics associated with coring these relatively deep lakes has meant that the lake level reconstructions are relatively coarse in terms of their temoral resolution. For several reasons Quartz Lake in interior Alaska is logistically a much more attractive study site. Firstly, Quartz Lake is on the road system and is very easily accessed by our team from the University of Alaska Fairbanks (UAF). Secondly, our team from UAF can optimize the timing of field work at this relatively local site to coincide with ideal field conditions, including weather, day length and the lake ice being in place to be able to use it as a coring platform to work from. Thirdly, we have previously taken and published results from a core in the deepest part of Quartz Lake and have shown, by dating the core and analysing evidence preserved in the core, that the lake has experienced dramatic changes in climate, hydrology and ecology over the ~10,000 years since it appeared on the landscape. Here we propose to advance this research by taking multiple cores from sites across a transect from Quartz Lake, to date, compare and then construct a detailed picture of how the past lake levels have changed at the site over 10,000 years. This lake level reconstruction will then be used to compare with our previously published data that has illustrated how the chemistry, ecology and climate has changed at Quartz Lake over 10,000 years. This project will produce one of the most detailed lake level histories covering the last 10,000 years in interior Alaska. This project will also support the research of an undergraduate research student at UAF and will provide field work training for an additional group of undergraduate and graduate students from UAF.