Weichselian and Holocene climate history reflected in temperatures in the upper crust of the Netherlands

Abstract

In the Netherlands the present-day thermal gradient in the shallow subsurface (i.e. the upper few 100 m), is around 20°C km -1 , whereas at depths between 0.5 and 3 km it is ∼33°C km -1 . This large contrast in the gradient between shallow and deeper parts of the subsurface occurs throughout the country and cannot be explained by either systematic thermal property changes with depth or the depositional setting of the region. In this paper we use a 1D thermal model for the crust and demonstrate that this observed temperature-depth trend most likely reflects a transient condition inherited from past climate change. It is shown that the prolonged cold period during the Weichselian (∼110-10 kya) and the subsequent warmer conditions during the Holocene account for the increase in the thermal gradient with depth. Moreover, we demonstrate that thermal history further back in time still influences the present-day subsurface temperature. Geothermal climate-change influences on these long time scales have not been documented before for the Netherlands.

Tracking the Subsurface Signal of Decadal Climate Warming to Quantify Vertical Groundwater Flow Rates

“…Assuming a thermal conductivity of 2 W m −1 °C −1 for these fine marine sediments of Miocene age (Kooi, ), the geothermal heat flux at these depths is estimated at 45·10 −3 W m −2 . This is in agreement with other geothermal heat flux assessments for the Netherlands (e.g., ter Voorde et al, ).…”

Weichselian permafrost depth in the Netherlands: a comprehensive uncertainty and sensitivity analysis

“…This allows the possibility of a future glacial colder than the Weichselian analogue (e.g. the Saalian, when the Fennoscandian ice-sheet margin reached the Netherlands; Svendsen et al, 2004). Furthermore, a 21 • C temperature drop for the LGM is in line with the coldest estimate reconstructions for low lying areas in Great Britain (Busby et al, 2015).…”

Advancement toward coupling of the VAMPER permafrost model within the Earth system model <I>i</I>LOVECLIM (version 1.0): description and validation

“…Figure 12 shows a map of the selected GTN-P measurements. All the temperature comparisons are within the top 30 m of the subsurface and therefore reflect recent climate as opposed to the deeper temperatures (i.e., > 150 m) that, depending on subsurface thermal diffusivity and surface temperature perturbations, can reflect historical temperatures of at least 100 years ago (Huang et al, 2000) and up to tens of thousands of years (Ter Voorde et al, 2014). Figure 11 illustrates that VAMPERS does a reasonable job of predicting shallow subsurface temperatures (Pearson correlation = 0.64).…”