Øystein S. Lohne

Bio: Øystein S. Lohne is an academic researcher from Bjerknes Centre for Climate Research. The author has contributed to research in topics: Ice sheet & Younger Dryas. The author has an hindex of 17, co-authored 22 publications receiving 1617 citations. Previous affiliations of Øystein S. Lohne include University of Bergen.

The last Eurasian ice sheets - a chronological database and time-slice reconstruction, DATED-1

Abstract: We present a new time-slice reconstruction of the Eurasian ice sheets (British–Irish, Svalbard–Barents–Kara Seas and Scandinavian) documenting the spatial evolution of these interconnected ice sheets every 1000 years from 25 to 10 ka, and at four selected time periods back to 40 ka. The time-slice maps of ice-sheet extent are based on a new Geographical Information System (GIS) database, where we have collected published numerical dates constraining the timing of ice-sheet advance and retreat, and additionally geomorphological and geological evidence contained within the existing literature. We integrate all uncertainty estimates into three ice-margin lines for each time-slice; a most-credible line, derived from our assessment of all available evidence, with bounding maximum and minimum limits allowed by existing data. This approach was motivated by the demands of glaciological, isostatic and climate modelling and to clearly display limitations in knowledge. The timing of advance and retreat were both remarkably spatially variable across the ice-sheet area. According to our compilation the westernmost limit along the British–Irish and Norwegian continental shelf was reached up to 7000 years earlier (at c. 27–26 ka) than the eastern limit on the Russian Plain (at c. 20–19 ka). The Eurasian ice sheet complex as a whole attained its maximum extent (5.5 Mkm2) and volume (~24 m Sea Level Equivalent) at c. 21 ka. Our continental-scale approach highlights instances of conflicting evidence and gaps in the ice-sheet chronology where uncertainties remain large and should be a focus for future research. Largest uncertainties coincide with locations presently below sea level and where contradicting evidence exists. This first version of the database and time-slices (DATED-1) has a census date of 1 January 2013 and both are available to download via the Bjerknes Climate Data Centre and PANGAEA (www.bcdc.no; http://doi.pangaea.de/10.1594/PANGAEA.848117).

Glacial history of Norway

Abstract: The Scandinavian Ice Sheet formed around 12.6 Ma and expanded considerably from 2.7 Ma. During the Weichselian the western margin reached the coast during Marine Isotope Stage (MIS) 5d and the continental shelf during MIS 5b, MIS 4 and MIS 2. It was almost gone during MIS 5c and 5a, and was much reduced during periods of MIS 3, notably the Alesund interstadial. There was a re-advance during the Younger Dryas.

Record-breaking height for 8000-year-old tsunami in the North Atlantic

Abstract: One of the largest Holocene sub-marine slides mapped on Earth is the Storegga slide offshore Norway [Bugge, 1987] (Figure 1). Approximately 3500 km3 material slid out and generated a huge tsunami dated to about 7300 14C yr BP [Bondevik et al., 1997a], or ca 8150 calendar years BP. The tsunami is known from onshore deposits in Norway [Bondevik et al., 1997a], on the Faroe Islands [Grauert et al., 2001], and in Scotland [Dawson et al., 1993]. Of these, the tsunami deposits in western Norway reaches the highest elevation, indicating a runup of 10–12 m. In this article, we demonstrate that at the Shetland Islands between Norway and Scotland (Figure 1), this tsunami reached onshore heights at least 20 m above the sea level of that time.

Late glacial and holocene 10Be production rates for western Norway

Abstract: We present a new regional calibration of the 10Be production rate from two well-dated surfaces insouthern Norway: a rock avalanche with 14C-dated wood and a precisely dated Younger Dryas moraine. C ...

Sea level and global ice volumes from the Last Glacial Maximum to the Holocene.

Abstract: The major cause of sea-level change during ice ages is the exchange of water between ice and ocean and the planet's dynamic response to the changing surface load. Inversion of ∼1,000 observations for the past 35,000 y from localities far from former ice margins has provided new constraints on the fluctuation of ice volume in this interval. Key results are: (i) a rapid final fall in global sea level of ∼40 m in <2,000 y at the onset of the glacial maximum ∼30,000 y before present (30 ka BP); (ii) a slow fall to -134 m from 29 to 21 ka BP with a maximum grounded ice volume of ∼52 × 10(6) km(3) greater than today; (iii) after an initial short duration rapid rise and a short interval of near-constant sea level, the main phase of deglaciation occurred from ∼16.5 ka BP to ∼8.2 ka BP at an average rate of rise of 12 m⋅ka(-1) punctuated by periods of greater, particularly at 14.5-14.0 ka BP at ≥40 mm⋅y(-1) (MWP-1A), and lesser, from 12.5 to 11.5 ka BP (Younger Dryas), rates; (iv) no evidence for a global MWP-1B event at ∼11.3 ka BP; and (v) a progressive decrease in the rate of rise from 8.2 ka to ∼2.5 ka BP, after which ocean volumes remained nearly constant until the renewed sea-level rise at 100-150 y ago, with no evidence of oscillations exceeding ∼15-20 cm in time intervals ≥200 y from 6 to 0.15 ka BP.

The last Eurasian ice sheets - a chronological database and time-slice reconstruction, DATED-1

Abstract: We present a new time-slice reconstruction of the Eurasian ice sheets (British–Irish, Svalbard–Barents–Kara Seas and Scandinavian) documenting the spatial evolution of these interconnected ice sheets every 1000 years from 25 to 10 ka, and at four selected time periods back to 40 ka. The time-slice maps of ice-sheet extent are based on a new Geographical Information System (GIS) database, where we have collected published numerical dates constraining the timing of ice-sheet advance and retreat, and additionally geomorphological and geological evidence contained within the existing literature. We integrate all uncertainty estimates into three ice-margin lines for each time-slice; a most-credible line, derived from our assessment of all available evidence, with bounding maximum and minimum limits allowed by existing data. This approach was motivated by the demands of glaciological, isostatic and climate modelling and to clearly display limitations in knowledge. The timing of advance and retreat were both remarkably spatially variable across the ice-sheet area. According to our compilation the westernmost limit along the British–Irish and Norwegian continental shelf was reached up to 7000 years earlier (at c. 27–26 ka) than the eastern limit on the Russian Plain (at c. 20–19 ka). The Eurasian ice sheet complex as a whole attained its maximum extent (5.5 Mkm2) and volume (~24 m Sea Level Equivalent) at c. 21 ka. Our continental-scale approach highlights instances of conflicting evidence and gaps in the ice-sheet chronology where uncertainties remain large and should be a focus for future research. Largest uncertainties coincide with locations presently below sea level and where contradicting evidence exists. This first version of the database and time-slices (DATED-1) has a census date of 1 January 2013 and both are available to download via the Bjerknes Climate Data Centre and PANGAEA (www.bcdc.no; http://doi.pangaea.de/10.1594/PANGAEA.848117).