Department of Earth Sciences

Scientific Drilling - text from the old webbpage

Rocks and sediments on continents and in ocean basins provide a record of the development of planet Earth. Knowledge about the history of planet Earth is important for our civilization, amongst others for the sustainable development of natural resources, the knowledge about the climate on different time-scales, how dynamic processes in the Earth's crust can lead to natural disasters and about the nature of ecosystems and how they are affected by human activities. Geoscientific information from the underground is expensive and drilling is often the only way to obtain samples and in-situ measurements. Since drilling on continents and oceans requires advanced infrastructure, two major international scientific programmes were developed to support scientific drilling, the International Continental Scientific Drilling Program (ICDP) and the International Ocean Discovery Program (IODP). Sweden is a member in both programmes and national interests are coordinated in the Swedish Scientific Drilling Program (Swedish Scientific Drilling Program SSDP, before SDDP) at Uppsala University. SSDP supports Swedish researchers who have an interest in scientific drilling and helps with the development and conduction of scientific drilling projects.

A scientific drilling project that is led by researchers at Uppsala University is Collisional Orogeny in the Scandinavian Caledonides (COSC). The main target of COSC is to study mountain building processes in major orogens, like the Himalayas. These processes are active tens of kilometres below the surface, and their expression (e.g. the Tibetan Plateau) and consequences (e.g. earthquakes and other natural disasters) affect millions of people. Unfortunately, it is not possible to study these deep processes directly in a modern mountain belt (orogen). The Caledonian mountain belt was similar in size to today's Himalayas about 400 million years ago, and was deeply eroded since then. Rocks that were deformed at mid-crustal level during Caledonian orogeny are now exposed at the surface. COSC studies a key-area of the Caledonides that is located in the Scandinavian mountains of Jämtland, Sweden, with the aim to compare traces after “fossil” processes with knowledge from major modern mountain chains like the Himalayas, to further our understanding on how orogens develop and how mountain building changed over time. Two drill holes to 2.5 km depth will provide a continuous sample (drill core) and, thus, profile through a part of the mountain chain that was transported several hundreds of kilometres onto the Fennoscandian Shield. During 2014, we have successfully drilled the first borehole, COSC-1, with financing from ICDP and the Swedish Research Council (VR). The second borehole, COSC-2, is in the planning and financing stage. COSC is an international project with about 50 participating researchers from more than 10 countries. It is led by researchers at the geophysics programme at Uppsala University. COSC research is much wider than mountain building. Researchers are concerned, amongst others, with physical rock properties, they model the groundwater flow and how it affects the heat transport in the rock. The steady state temperature profile in the borehole can be used to reconstruct the development of the surface temperature for the last 100000 years. Microbiologists study the deep biosphere, i.e. microbes that live in this special environment at depth.