Marine Isotope Stage 31: the “hottest” interglacial in the Arctic?

Marine Isotope Stage 31 is arguably one of the warmest interglacials in the Quaternary. This interglacial is special because of high insolation, which is among the highest compared to any other Quaternary interglacial. As a result, proxy records show strong warming in the Southern Ocean (>5˚C than today, Beltran et al. 2020, QSR 228), and also the Lake Elgygytgyn paleorecord indicates temperatures considerably warmer than present. We only have anecdotal evidence from the Arctic Ocean and Nordic Seas about how warm MIS 31 was there. This is important to find out, as warming in the Arctic, today happening via increased warm water inflow and elevated greenhouse gases, strongly impacts the Arctic sea ice extent and the Greenland ice sheet.

Supervisors

Main supervisor: Stijn De Schepper, UiB-GEO/NORCE
Co-supervisor: Bjørg Risebrobakken, NORCE
Co-supervisor: Ulysses Ninnemann, UiB-GEO

Project description

Research question: How much warmer is MIS 31 compared to MIS 5e and the Holocene in the Nordic Seas? 

Work plan: You will identify MIS 31 and reconstruct the sea surface temperature in ODP sites 985 and/or Site 644 in the Nordic Seas. Sampling will be done at the Bremen core repository in Germany. You will count ice rafted detritus and absolute abundance of foraminifera, pick foraminifera to generate a stable oxygen isotope record, and you will generate a Mg/Ca based sea surface temperature record using the planktonic foraminifer N. pachyderma. You will compare your findings with previously published records from MIS 5 and the Holocene, to evaluate whether MIS 31 is the “hottest” interglacial in the Quaternary. Optional: You can use microscopy to analyse the dinoflagellate cysts assemblages to document the sea surface conditions and ocean currents. 

The thesis work will be integrated in the ERC Synergy project i2B (www.in2blue.eu (external link)).

The student starting this project must have taken GEOV110 or equivalent.

Field-, lab- and analysis work

Sampling at the IODP core repository in Bremen (1 week).
Microscope and geochemical lab work ca. 6 months.

Proposed course plan

Fall semester H26:
GEOV222: Palaeoclimatology (10 ECTS)
GEOV324: Polar Palaeoclimate (5 ECTS)
GEOV300: Scientific writing and communication in Earth Science (5 ECTS)
 

Spring semester V27:
GEOV231: Marine Geological Field-and Laboratory Course (10 ECTS)
GEOV302: Data analysis in earth science (10 ECTS)
GEOV331: Paleoceanography (5 ECTS)
GEOV342: The geochemical toolbox (10 ECTS)
GEOV322: Master Level Field Excursion in Quaternary Geology (5 ECTS)
 

Alternative Course Suggestions:
GEOF338: Polar Oceanography (Spring semester, 10 ECTS)
GEOV336: Lab- og metodekurs i kvartærgeologi (Høst 2026, 10 ECTS)

Last updated: 23.06.2026