HEAS Talk with Alan Cooper
Mai 28 @ 10:30 - 12:30
We are looking forward to welcoming Prof. Alan Cooper from Gulbali Institute, Charles Sturt University, Australia to Vienna for a HEAS Talk on What has the Earth’s Magnetic Field ever done for us?
Environmental and Archaeological Transitions on the 28th May at 10:30 CEST.
The central role of the earth’s geomagnetic field in permitting life on earth is generally overlooked, potentially due to our own inability to sense or use magnetic fields, unlike many other species. The importance of this protection rapidly becomes obvious when the geomagnetic field strength collapses (eg during a geomagnetic excursion), which happens regularly throughout the geological record. During weak field phases, the impacts of ionising cosmic radiation (solar and galactic) on the upper atmosphere can be seen as increased rates of cosmic nuclide production (eg.14C, 10Be). The impacts are particularly strong during fluctuations in solar radiation (eg Grand Solar Minima, or Solar Proton Events), and modelling predicts these would lead to marked changes in ozone distribution, UV radiation levels and climate patterns.
The best known recent geomagnetic excursion (Laschamps, 42-41ka) saw a marked increase in 14C production during Grand Solar Minima, and this event is contemporaneous with many global environmental and archaeological transitions (eg. Neandertal extinction, arrival of Aurignacian populations) – although precise modes of action remain unclear. However, there are many other geomagnetic excursions throughout the Late Pleistocene, raising questions about their potential role across paleoclimatic and paleoanthropological records at multiple scales. Preliminary analysis of global ice, sediment 10Be and geomagnetic records over the past 130ka reveals a wide variety of unexpected patterns and associations with global events, and indicate the need for detailed analyses of the impacts and events during an excursion. This information is also required to plan for future solar weather events which will occur this century, and have the potential for destructive impacts on modern life.