Precise linking of late Quaternary palaeoclimate records in the North Atlantic region


Project leader


Funding source

Swedish Research Council - Vetenskapsrådet (VR)


Project Details

Start date: 01/01/2016
End date: 31/12/2019
Funding: 2950000 SEK


Description

The aim of the project is to get a better understanding of rapid climate changes in the past and to compare climate signals preserved in different high-resolution climate archives in the North Atlantic region. We will address this research question by analysing high-resolution palaeoclimate records spanning the time interval from the onset of the first warm period of the last deglaciation until the early Holocene (c. 14-8 ka BP). Several climate tipping points occur in this time frame and better understandings of these are critical for the paleoclimate and modelling communities. It has generally been assumed that major climate re-organisations were time-synchronous on continental and hemispheric scales but recent results suggest that both the onset as well as the termination of the Younger Dryas cold reversal may have been time-transgressive. Time-synchronous tephra markers will be used to line up palaeoclimate records and we will contribute with precisely linked palaeoclimate records which allow testing hypotheses regarding synchronous or non-synchronous responses to climate forcing. Few, if any geochronological methods can match the precision tephrochronology offers both temporally and spatially. The southern Baltic region is the main area of investigation with links to the Greenland ice cores. Recent investigations show that comprehensive distal tephra networks can be built in the southern Baltic region and we will investigate both annually varved sequences and key terrestrial lake sequences. The Vedde Ash (c. 12.1 ka BP) was recently identified in a varve sequence from eastern Sweden and we will use this extremely useful marker and other tephra isochrons to align our climate archives, including the Greenland ice cores and annually resolved European lake records, including Meerfelder maar in SW Germany. We will also use the Vedde Ash to estimate the error in the Swedish varve chronology. The Swansea tephra group, UK is already working with ice core samples from Greenland and will provide ice-core years for the key tephras of our study. The main aims are closely linked to each other and the expected results will also be valuable for the IODP expedition 347, “Baltic Sea Basin Paleoenvironment” by providing isochrones represent-ting fixed time-lines between different proxy records and areas. The results from this project will be of major importance for both science and society. Our tephra-based correlations will provide useful information for the climate modelling community, especially as models now need to capture abrupt changes on short time-scales. A second benefit will be that a well-dated Late Quaternary tephra network will be developed for NW Europe. This will be of major importance for palaeoenvironmental reconstructions and for dating and correlation of peat, lake, marine sediment and ice-cores. The relatively small eruption of Eyjafjallajökull in 2010 made us aware of the vulnerability of modern society. It is widely recognised that other volcanoes on Iceland may cause similar or even larger problems in future, especially since we now may enter a time period of increased volcanic activity on Iceland. An eruption from Katla is long overdue, and when it eventually erupts, it will cause severe problems for air-travel and other activities for months or years. To prepare for future events, we need to know more about past volcanic events that have affected North Europe and with this project we will increase the knowledge about past eruptions that have reached Scandinavia and Greenland.


External Partners


Last updated on 2017-28-07 at 11:12