Seasonal climate variations in the Baltic Sea during the Last Interglacial based on foraminiferal geochemistry
Journal
Quaternary Science Reviews
Journal Volume
272
Date Issued
2021
Author(s)
Abstract
Climate during the Last Interglacial period (LIG, Marine Isotope Stage 5e) was on average warmer than the present, with a higher global sea level but also more unstable conditions. Today, the Baltic Sea interacts strongly with conditions in the North Atlantic region, and this interaction was likely even stronger during the LIG. We here present a reconstruction of seawater conditions during the LIG based on benthic foraminiferal geochemistry (stable isotopes and trace elements) and compare these records with modern marine monitoring data to evaluate seasonal hydrographic conditions in the western and southern Baltic Sea during the first half of the LIG (130–123 ka BP). Our reconstructions reflect the evolution of seasonal temperature and salinity, rather than annual mean conditions. The spring LIG bottom water temperatures in the Skagerrak and Kattegat were ∼2–3 °C higher compared to the modern spring bottom water temperatures. During the LIG, there was an increase in seasonality in bottom water temperature (progressively warmer summers and cooler springs) in the southern Baltic Sea, which can be linked to seasonal insolation changes. Moreover, our data suggest a decreased gradient of bottom water salinity along a transect through the Skagerrak-Kattegat-Danish Straits-southern Baltic Sea, supporting previous investigations inferring a stronger ocean-water influx into the Baltic Sea during the LIG than at present. © 2021 The Authors
Subjects
Benthic foraminifera; Hydrography; Seasonality; The Baltic Sea; The Last Interglacial; The Skagerrak
SDGs
Other Subjects
Geochemistry; Isotopes; Sea level; Trace elements; Benthic foraminifera; Condition; Foraminiferal geochemistry; Seasonality; The baltic sea; The last interglacial; The skagerrak; Temperature; bottom water; foraminifera; insolation; Last Interglacial; salinity; sea level; seasonal variation; seasonality; transect; water temperature; Atlantic Ocean; Atlantic Ocean (North); Baltic Sea; Foraminifera
Type
journal article