We are studying Holocene chironomid and diatom assemblages in Russia to identify the drivers of global climate change. Kamchatka, in the northeast of Russia, is an important region for understanding key climate links between the North Atlantic and North Pacific regions.
We are analysing chironomids from three sites in Kamchatka, at intervals of 40-80 years throughout the Holocene. Using the midge thermometer, this information will allow us to quantify Holocene summer air temperatures.
Changes in seasonality are estimated by the chironomids found:
- A continental climate results from westerly winds blowing across northern Eurasia, bringing cold winters, short warm summers and less rainfall.
- An oceanic climate results from Pacific winds bringing milder winters, cooler summers and more rain.
We are also analysing diatoms to quantify changes in the length of the summer and variations in pH and nutrients. We will compare our results with records of vegetation change and volcanic activity developed by colleagues at Queens University Belfast and AWI Potsdam.
Stable oxygen isotopes: Alex Lombino
An innovative aspect of this project is the analysis of stable oxygen isotopes in chironomid heads, which are made from chitin.
Oxygen in the chitin molecule is derived from the lake water in which it lives. The ratio of stable oxygen isotopes incorporated into the chironomid heads reflects that of the water source.
In non-evaporative lakes this reveals which air masses were driving the prevailing climate at that time, Eurasia or the North Pacific.
By comparing our records with Holocene climate records from other sites, we will be able to establish the extent of global climate links at times of different climatic regimes, for example the magnitude and timing of the Holocene Thermal Maximum and the Little Ice Age.
Arctic Russia: Dr Angela Self
The team have developed novel chironomid-based quantitative summer air temperature inference models. These have been applied to four lake sediment sequences from northern Russia as part of a multiproxy study of Holocene environmental change.
One model is based on a modern calibration set of 80 lakes from northwest and central Russia, the first of its kind for this region, and another combines elements of a modern Norwegian calibration set with the Russian calibration set.
Reconstructing a highly detailed record of environmental and climatic change over thousands of years.
Our researchers study the impacts of environmental change in a range of UK freshwater systems.
How the emergence of adult chironomids from saline lakes can support terrestrial food webs.