| 1. |
- Kehoe, Laura, et al.
(author)
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Make EU trade with Brazil sustainable
- 2019
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In: Science. - : American Association for the Advancement of Science (AAAS). - 0036-8075 .- 1095-9203. ; 364:6438, s. 341-
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Journal article (other academic/artistic)
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| 2. |
- Ohrling, C., et al.
(author)
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Meteorite crater re-interpreted as iceberg pit in west-central Sweden
- 2021
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In: Gff. - : Informa UK Limited. - 1103-5897 .- 2000-0863. ; 143:1, s. 84-91
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Journal article (peer-reviewed)abstract
- This study shows the occurrence of numerous iceberg imprints on the bottom of former ice-dammed lakes in Harjedalen, west-central Sweden. Discussion of the genesis of the so-called "impact crater" known as the Tor structure at Torbygget, which is located in this area, motivated an examination of the area using high-resolution digital elevation models. Previous investigations have suggested that this crater was created by a meteorite impact about 2000 years ago, forming a semi-round depression. The results of our investigation clearly indicate that the feature was formed by a grounding iceberg, scouring the bed of an ice-dammed lake during deglaciation about 11 000-10 000 cal. BP. Geomorphic evidence of an ice-dammed lake (multiple and abundant well-developed shorelines) are consistent with earlier mapping efforts in the area. Furthermore, an abundance of geomorphological traces of iceberg activity is found within the paleo-ice-dammed lake basins. Based on this we suggest that the depression at Torbygget is not an impact crater but formed by a grounded iceberg.
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| 3. |
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| 4. |
- Johnson, Mark D., 1954, et al.
(author)
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Geomorphology and sedimentology of features formed at the outlet during the final drainage of the Baltic Ice Lake
- 2022
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In: Boreas. - : Wiley. - 0300-9483 .- 1502-3885. ; 51:1, s. 20-40
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Journal article (peer-reviewed)abstract
- We present a conceptual model for the character of the 11.6 cal. ka BP drainage of the Baltic Ice Lake in the outlet area based on a new geomorphological map as well as new sedimentological information. We combine this new information with a review of the previous work on this well-studied area. The model includes the premise of remnant ice in the Langen valley as suggested by previous workers and indicates the drainage began subglacially. Cobbly sediment on northeast Billingen formerly interpreted as beach sediment is interpreted to be a subglacial lag deposit. The ridge at Timmersdala is composed of drainage sediment from the initial phases of the drainage, deposited in a subglacial tunnel that emptied out on to central Klyftamon. Continued drainage widened the tunnel by frictional melting, eventually lifting and fracturing the ice. Pendant bars, expansion bars and boulder sheets on central and southern Klyftamon formed during the drainage event. Cobbly and bouldery drainage sediment in the bars, which is massive and poorly sorted, was deposited as bedload from sediment-charged water. Imbrication, bar orientation, and changes in grain size and Cambrian-clast content indicate flow to the west-northwest. Most sediment in the bars was derived from erosion on Klyftamon, but Cambrian rock from Billingen is present, delivered directly by the flood waters and/or from debris-rich icebergs from the broken-up remnant ice. This flood event is distinguished from other Quaternary megafloods by being sediment-supply limited and having a short, subaerial floodway (20 km).
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| 5. |
- Ojala, A. E. K., et al.
(author)
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Ice-sheet scale distribution and morphometry of triangular-shaped hummocks (murtoos): a subglacial landform produced during rapid retreat of the Scandinavian Ice Sheet
- 2019
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In: Annals of Glaciology. - : Cambridge University Press (CUP). - 0260-3055 .- 1727-5644. ; 60:80, s. 115-126
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Journal article (peer-reviewed)abstract
- High-resolution digital elevation models of Finland and Sweden based on LiDAR (Light Detection and Ranging) reveal subglacial landforms in great detail. We describe the ice-sheet scale distribution and morphometric characteristics of a glacial landform that is distinctive in morphology and occurs commonly in the central parts of the former Scandinavian Ice Sheet, especially up-ice of the Younger Dryas end moraine zone. We refer to these triangular or V-shaped landforms as murtoos (singular, `murtoo'). Murtoos are typically 30-200 m in length and 30-200 m in width with a relief of commonly <5 m. Murtoos have straight and steep edges, a triangular tip oriented parallel to ice-flow direction, and an asymmetric longitudinal profile with a shorter, but steeper down-ice slope. The spatial distribution of murtoos and their geomorphic relation to other landforms indicate that they formed subglacially during times of climate warming and rapid retreat of the Scandinavian Ice Sheet when large amounts of meltwater were delivered to the bed. Murtoos are formed under warm-based ice and may be associated with a non-channelized subglacial hydraulic system that evacuated large discharges of subglacial water.
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