Holocene climatic fluctuations
in the midcontinent of North America
I study Holocene climatic fluctuations, focusing on the midcontinent
of North America. I use a variety of climate proxies from lake
sediment, including oxygen isotopes from carbonates, trace element
geochemistry, mineralogical composition, and biological indicators
of productivity. Preliminary results from Steel
Lake, Minnesota, show distinct climate characteristics over
different periods of the Holocene, including both abrupt climate
change and cyclic oscillations. This site has varved sediments,
providing precise chronological control enabling high-resolution
Selecting sites in a
climatically-sensitive region allows accurate documentation of past
Varved sediments provide precise
chronological control and enable high-resolution analyses.
A multiple-proxy approach results
in a comprehensive understanding of the system.
- Calibrate various climatic proxies in varved sediments with
available instrumental weather data to evaluate how each proxy
is related to climatic factors.
- Assess Holocene climatic variations, particularly cyclic
and abrupt changes, by interpreting proxy records from all four
lakes based on calibration results.
- Integrate our new varved sediment data with findings from
other high-resolution paleoclimatic studies in adjacent areas
to provide a regional synthesis of Holocene climatic variations.
- Compare patterns of climatic fluctuations in the midcontinent
of North America with those in Greenland, North Atlantic, and
other parts of the globe to evaluate patterns and mechanisms
of Holocene climatic variability.
||46° 58'N, 94° 41'W
||Hubbard County, MN
||46° 37'N, 96° 11'W
||Otter Tail County, MN
||Clearwater County, MN
||Becker County, MN