Tropical climate variability and speleothem science Research methods

We use so-called climate archives, such as speleothems and corals, to quantify information about past climate and environmental changes, as well as to better understand the relationships and dynamics within the system across various time scales. To do this, we use a variety of methods:

Trace Elements in Speleothems

A key method in our work is the determination of trace element concentrations in speleothems and corals using laser ablation mass spectrometry (LA-ICP-MS). For this purpose, we have an NWR193UC excimer laser ablation system from NewWave Research (NWR) available in the laboratory of the Institute of Environmental Physics. The system features a large ablation cell, which allows us to analyze even larger samples with minimal sample destruction. Coupling to an iCAP QTM quadrupole mass spectrometer with an inductively coupled plasma source allows for fast and reliable measurement of several trace elements such as Mg, Sr, Ba, as well as Cu, Ni, and Al in concentration ranges of a few µg/g.

Fluid inclusions

The carbonate in speleothems often contains microscopic fluid inclusions that preserve remnants of past dripwater. Using our custom-built system, we can determine the isotopic composition of the water in these inclusions and thereby draw conclusions about past precipitation conditions and temperatures.  

other Methods

To pinpoint the timing and duration of these changes, we use the Th/U dating method, which plays a central role in the PUA group. This method allows us to date speleothems and corals with an accuracy of a few years. 
We also work closely with our colleagues in the Earth Sciences (Keppler and Friedrich Research Groups) to, for example, determine the carbon and oxygen isotopes in the carbonate of speleothems and use them as climate proxies. In addition, the Institute of Earth Sciences (Group Rojas-Agramonte) hosts a high-resolution ion probe, the Heidelberg Ion Probe (HIP), which can be used to analyze isotopic and elemental composition on the micrometer scale.
In addition, for imaging techniques, we use confocal laser scanning fluorescence microscopy at the Nikon Imaging Center at Heidelberg University to visualize fluorescent organic components in speleothems. 

More

Further information about our research activities can be found in our publications. If you are interested in writing a thesis or doing an internship in one of our research areas, please feel free to contact us.