Visit to the KTB

As part of the recently started ERC project ICED, Georgina and Lily visited to the KTB borehole, Windinscheschenbach (Bavaria) to collect a range of calibration samples. The KTB borehole was drilled between 1987 and 1995 reaching a depth of 9 km and temperatures of over 300 °C. Because this region has been tectonically stable over 10s of millions of years, these samples have experienced stable temperatures and thus provide an excellent calibration set for thermochronometry. These samples will be used to confirm the performance of the electron spin resonance (ESR) thermochronometry method.

Lily happy amongst the sample cores.
The drill rig used to sample the main KTB borehole (our samples are from the test borehole, which was located nearby).

Vjeran’s publication on inverting past ice extents to constrain paleo-mass balances.

Congratulations to Vjeran! Here is the link.

With the conclusion of the Last Glacial Maximum (LGM), about 20 000 years ago, ended the most recent long-lasting cold phase in Earth history. This last glacial advance left a strong observable imprint on the landscape, such as moraines, trimlines and other glacial geomorphic features. These features reflect the extent of former glaciers and ice caps, which in turn provides information on past temperature and precipitation conditions. Here we present an inverse approach to reconstruct the equilibrium line altitudes (E) from observed ice extents. The ice-flow model is developed solving the mass conservation equation using the shallow ice approximation and implemented using Graphical Processing Units (GPUs). We present the theoretical basis of the inversion method, which relies on a Tikhonov regularization, and demonstrate its ability to constrain spatial variations in mass balance with idealized and real glaciers.