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Map of northwestern Norway showing the location of investigated fjords and lakes and position of fjord cores. M: Medvatnet; N: Nedstevatnet; R: Rotevatnet; S: Storsaetervatnet.
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Seismic profiles and sediment cores from sixteen fjords and five lakes in western Norway have been investigated in a search for Holocene mass-movement deposits. Tsunami deposits caused by the Storegga Slide (8200 cal. BP) are observed over most of the investigated area, both in fjords and in lakes. Five fjords provide evidence for a 2000-2200 cal....
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... Norwegian coast was hit by a large tsunami caused by the Storegga Slide ( Fig. 1) at 8200 cal. BP ( Bondevik et al. 1997a, b, Bryn et al. 2002. The tsunami is recog- nized in the sedimentary record of coastal lakes as an erosional unconformity overlain by graded or massive sand with shell fragments, followed by redeposited organic detritus. These features can be seen along the coast, the highest levels being 10-11 ...
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... by graded or massive sand with shell fragments, followed by redeposited organic detritus. These features can be seen along the coast, the highest levels being 10-11 m above the sea level of the time and in areas most proximal to the slide scar, in Sunnmøre. Sejrup et al. (2001) investigated an 8.5 m long core from Voldafjorden in Sunnmøre ( Fig. 1) and found tur- bidites at the ca. 2000, 8200 and 11 000 cal. BP ...
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... that occur at the level of major debris flow deposits along the submarine slopes of Vol- dafjorden. This suggested that both events could possi- bly be related to large tsunamis caused by offshore mega-slides ( Longva et al. 2001). Similar debris-flow deposits were observed in seismic data from other fjords between Sognefjorden and Kristiansund ( Fig. 1), and occasionally occur at the same stratigraphic level as in ...
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... locations were chosen after interpretation of the seismic and acoustic data. The majority of the cores were aimed at penetrating mass-movement deposits. Cores were obtained from 41 fjord locations using HYBAV vibrocorer, gravity corer and Selcore, and from 26 locations in five lakes using piston corer (Fig. 1). All cores were investigated by means of X-ray inspection (XRI) and multi-sensor core logging (MSCL). Cores containing mass-movement deposits were sedimento- logically described, and subsampled for grain-size ana- lysis and 14 C-dating. In this paper we mainly treat sedi- ment cores that have been dated; full datasets can be found in ...
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... data show that acoustically chaotic deposits occur at two stratigraphic levels in Julsundet (Fig. 5); core NGU-6LSC (Fig. 11) An upward fining unit with an erosive lower boundary occurs at 0.88-2.67 m core depth (Fig. 4). The unit can be correlated with acoustically chaotic deposits, above a well-defined seismic reflector (Fig. 5). From base to top the unit comprises 1) 5 cm gravel with clasts up to 1 cm and clay clasts from the underlying unit up to 2 cm, 2) ...
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... uppermost 6.91 m of this core (Fig. 4) comprise strongly bioturbated, olive grey, homogeneous silty clay/clayey silt with many shells and shell fragments less than 1 mm in diameter and five normally graded sand and silt turbidites (Fig. 11). Millimeter-scale concreti- ons and rods of authigenic pyrite occur abundantly in the interval 6.11-6.36 m. Homogeneous, light grey clay occurs in the lowermost part of the ...
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... data show that a large part of the inner fjord basin in Aurlandsfjorden (inner part of Sognefjorden, Fig. 1 ...
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... Syvdsfjorden, swath bathymetry ( Fig. 9) and seismic data (Fig. 10) show slide scars, debris-flow deposits and associated reflectors at several stratigraphic levels. Debris lobes, frequently stacked, occur along the nor- theastern and southwestern fjord margins as well as axially along the fjord. One turbidite occurs in core P0103018, while a debris-flow deposit with shells, wood fragments and mud ...
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... gave ages of 2333 cal. BP and 1780 cal. BP, respectively. The short distance between the two cores suggests that the turbidite in P0103018 and the debris- flow deposit in P0103019 can be correlated. The diffe- rence in depth, thickness and lithology is probably due to sedimentological variations along the outer margin of a debris-flow lobe ( Figs. 9 and 10). Seismic correla- tion between cores P0103017 and P0103019 suggests that two thin turbidites in P0103017 ( Fig. 9) are around 1000 years old. ...
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... data (Fig. 11) show that major debris-flow wed- ges occur at three stratigraphic levels along the margins of Voldafjorden. In addition, the swath bathymetry exhibits two small, relatively young slide scars. The volumes of the wedges appear to decrease with age but prominent reflectors extending from them can be traced across the fjord basin (Fig. ...
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... data (Fig. 11) show that major debris-flow wed- ges occur at three stratigraphic levels along the margins of Voldafjorden. In addition, the swath bathymetry exhibits two small, relatively young slide scars. The volumes of the wedges appear to decrease with age but prominent reflectors extending from them can be traced across the fjord basin (Fig. 11). A core penetrating reflectors associated with the two uppermost wedges, which have quite similar distributions (Fig. 12), was investigated by Sejrup et al. (2001) (see ...
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... In addition, the swath bathymetry exhibits two small, relatively young slide scars. The volumes of the wedges appear to decrease with age but prominent reflectors extending from them can be traced across the fjord basin (Fig. 11). A core penetrating reflectors associated with the two uppermost wedges, which have quite similar distributions (Fig. 12), was investigated by Sejrup et al. (2001) (see ...
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... slide scars occur along the subaerial slopes of Tafjorden. Swath bathymetry (Fig. 13) and seismic data (Fig. 14) show many large cones of rock-avalanche debris accumulated throughout the Holocene, and par- ticularly during the second half of this period. About 3 million m 3 ( Blikra et al. 2002) of rock and talus avalanched into Tafjorden in 1934 (Figs. 13 and 14), and the tsunami generated by the slide reached a maxi- ...
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... slide scars occur along the subaerial slopes of Tafjorden. Swath bathymetry (Fig. 13) and seismic data (Fig. 14) show many large cones of rock-avalanche debris accumulated throughout the Holocene, and par- ticularly during the second half of this period. About 3 million m 3 ( Blikra et al. 2002) of rock and talus avalanched into Tafjorden in 1934 (Figs. 13 and 14), and the tsunami generated by the slide reached a maxi- mum height of 62 m above ...
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... slide scars occur along the subaerial slopes of Tafjorden. Swath bathymetry (Fig. 13) and seismic data (Fig. 14) show many large cones of rock-avalanche debris accumulated throughout the Holocene, and par- ticularly during the second half of this period. About 3 million m 3 ( Blikra et al. 2002) of rock and talus avalanched into Tafjorden in 1934 (Figs. 13 and 14), and the tsunami generated by the slide reached a maxi- mum height of 62 m above sea level, killing 40 people. Even larger rock avalanches are identified below the 1934 slide deposits. A rock avalanche estimated to com- prise more than 100 million m 3 occurs on land ( Blikra et al. 2002). The avalanche debris can be traced into the ...
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... on top of the uppermost coarse grained bed points to a very young age, possibly the 1934 event, in which case the uppermost bed may be a tsunami deposit. From sedimentation rates, it can be estimated that the two other turbidites/tsunami deposits in P0103026 occurred around 1700 cal. BP and 2500 cal. BP, but these ages are very approximate. (Fig. 14) and a core (Fig. 7) are shown. See inset map and Fig. 1 for location. ...
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... a very young age, possibly the 1934 event, in which case the uppermost bed may be a tsunami deposit. From sedimentation rates, it can be estimated that the two other turbidites/tsunami deposits in P0103026 occurred around 1700 cal. BP and 2500 cal. BP, but these ages are very approximate. (Fig. 14) and a core (Fig. 7) are shown. See inset map and Fig. 1 for location. ...
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... is the offshore extension of Sulafjorden. The trough cuts approximately 100 m into the shelf and ends abruptly a few kilometres before it reaches the shelf edge/Storegga Slide escarpment. The swath bathy- metry ( Fig. 15) shows several debris flow lobes along the margins of the trough. Gravity core HM129-03 is located close to the southeastern margin of a debris flow deposit with a rugged surface morphology (Fig. 15). A sharp and undulating, erosive boundary, evident as a reflector in the seismic data, occurs at 1.6 m core depth (Fig. 7). Below the ...
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... 100 m into the shelf and ends abruptly a few kilometres before it reaches the shelf edge/Storegga Slide escarpment. The swath bathy- metry ( Fig. 15) shows several debris flow lobes along the margins of the trough. Gravity core HM129-03 is located close to the southeastern margin of a debris flow deposit with a rugged surface morphology (Fig. 15). A sharp and undulating, erosive boundary, evident as a reflector in the seismic data, occurs at 1.6 m core depth (Fig. 7). Below the boundary, bioturbated, sandy silt with numerous shells and shell fragments occurs. Samples from the uppermost and lowermost parts of this gave ages of 3352 cal. BP and 7011 cal. BP, respecti- vely. The ...
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... 129-04 was obtained 300 m southeast of HM129- 03. The swath bathymetry shows an even sea bed here, but the eastern boundary of an old debris flow deposit, with an upper boundary at ca. 2.4 m depth (estimated from seismic data), is well defined east of the coring location (Fig. 15). We interpret a transitional boundary at 1.15 m depth in this core to correlate with the boun- dary at 2.37 m depth in HM129-03, and the old debris flow deposit is thus older than 7011 cal. BP. If the corre- lation is correct, the bed of sandy silt below the boun- dary at 1.6 m depth thins towards the west, possibly as a result of ...
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... tion although the dating results indicate that the sedi- ments represent redeposited mass-movement deposits or possibly a slide block. All the investigated lake successions comprise Holocene gyttja on top of glaciolacustrine/glaciomarine sedi- ments. The gyttja frequently contains laminae and lay- ers of silt, sand and gravel. In Storsaetervatnet (Fig. 1), dating of a layer rich in organic material in the lower part of core S10 gave an age of 13 254 cal. BP (Fig. 16), which is interpreted to represent a minimum age for the deglaciation of the lake. Gyttja above an erosional boundary in cores S4 and S6 gave ages of 9181 cal. BP and 9006 cal. BP, indicating erosion (slumping) and removal ...
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... a slide block. All the investigated lake successions comprise Holocene gyttja on top of glaciolacustrine/glaciomarine sedi- ments. The gyttja frequently contains laminae and lay- ers of silt, sand and gravel. In Storsaetervatnet (Fig. 1), dating of a layer rich in organic material in the lower part of core S10 gave an age of 13 254 cal. BP (Fig. 16), which is interpreted to represent a minimum age for the deglaciation of the lake. Gyttja above an erosional boundary in cores S4 and S6 gave ages of 9181 cal. BP and 9006 cal. BP, indicating erosion (slumping) and removal of the uppermost glaciolacustrine sediments (including Vedde Ash) and the earliest Holocene gyttja, around 9200 ...
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... Rotevatnet (Fig. 1), three silt laminae in gyttja yiel- ded ages of 1820 cal. BP, 5314 cal. BP and 6700 cal. BP (Fig. 16). A silt lamina between the two oldest ones was not dated, but if we assume a constant sedimentation rate of the gyttja between the dated laminae, it is ca. 6200 cal. years old. Three silt laminae in the lower part of the gyttja are ...
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... Rotevatnet (Fig. 1), three silt laminae in gyttja yiel- ded ages of 1820 cal. BP, 5314 cal. BP and 6700 cal. BP (Fig. 16). A silt lamina between the two oldest ones was not dated, but if we assume a constant sedimentation rate of the gyttja between the dated laminae, it is ca. 6200 cal. years old. Three silt laminae in the lower part of the gyttja are interpreted to have been deposited in the earliest Holocene ca. 10-11 500 cal. ...
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... and silt laminae/layers in gyttja were dated in several cores from Medvatnet and Nedstevatnet (Figs. 1 and 16). These deposits are typically poorly sorted, and frequently contain pebbles and plant fragments. ...
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... gravelly sand unit, up to 35 cm thick, occurs in the lower part of the gyttja in all the cores from Medvatnet and Nedstevatnet (Fig. 16). It comprises two to four gravelly sand layers separated by thin, organic-rich horizons. The sand layers are massive, fining upwards or coarsening upwards. Wood fragments and crushed shells of bivalves and snails are common. The lower boundary, and often also the upper boundary of the unit, are sharp. The lithology and dating results ...
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... movements in western Norway have occurred at various times over the past 12 000 cal. years, but they were especially numerous at 2000-2200, 2800-3200, 8200 and before 10 000 cal. BP (Fig. 17, Table 3). Seve- ral thin silt and sand layers occur in the lowermost part of the Holocene gyttja and in the uppermost part of the glaciomarine succession, in several of the lake cores. Also the data from Voldafjorden and Halsafjorden show that the earliest Holocene was a time of frequent mass movements. We ascribe this mainly to high ...
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... dating and sedimentological interpretati- ons of cores have shown that mass-movement deposits related to the Storegga Slide tsunami occur in Sogne- sjøen (Haflidason 2002), Voldafjorden ( Sejrup et al. 2001), Sulafjorden, Julsundet and Halsafjorden (Table 3, Fig. 17). Also Medvatnet and Nedstevatnet exhibit a deposit that we ascribe to the Storegga Slide tsunami. Nedstevatnet was located a few metres below sea level at 8200 cal. BP, while Medvatnet was slightly above or close to it. The other investigated lakes were at too high an elevation to be reached by the tsunami wave and they show no trace ...
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... deposits in Aurlandsfjorden, Vanylvs- fjorden, Tafjorden, Julsundet, Storsaetervatnet and Ned- stevatnet cluster around 2800-3200 cal. BP (Table 3, Fig. 17). The age of 3329 cal. BP for a deposit beneath an erosion surface in a core from Beisunddypet sug- gests that this may possibly be ca. 3000 cal. years old also. In Medvatnet, a snow avalanche deposit has an age of 3279 cal. BP, while a debris flow occurred some time during 2600-3000 cal. BP. Dating below a turbidite in a core from ...
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... Voldafjorden ( Sejrup et al. 2001), Syvdsfjorden, Ørstafjorden, Førdefjorden and Dalsfjorden turbidites occur at 2000-2200 cal. BP (Table 3, Fig. 17). The turbi- dites in Syvdsfjorden and Voldafjorden are related to extensive debris-flow deposits along the fjord margins. It is possible that mass-movement deposits occur at the 2000-2200 cal. BP level also in Tafjorden, Breisunddy- pet, and Julsundet, but the dating results are not conc- lusive. Although we suggest that the the mass ...
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... data show that there is a striking similarity in areal distribution of major mass-movement deposits at the 2000-2200 cal. BP and 11 000-11 700 cal. BP strati- graphic levels in some fjords in Sunnmøre, e.g. in Vol- dafjorden ( Fig. 12) and Syvdsfjorden. This may suggest a common triggering mechanism. If our interpretation of the 2000-2200 cal. BP event above is correct, i.e. that debris flows and turbidites were caused by an earth- quake on land or close to the coast, then the older regi- onal event may have been triggered in the same ...
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... ca. 5800 cal. BP (Selsing & Wishman 1984;Kullman 1988;Gunnarsdóttir 1996), a higher fre- quency of large spring floods and debris flow after 5800 cal. BP (Blikra & Nemec 1998), and increasing snow- avalanche activity after 5400 cal. BP (Blikra & Selvik 1998). Mass-movement events in Rotevatnet and Ned- stevatnet around 6700-6800 cal. BP (Table 3, Fig. 17) correlate with neoglacial stages in western Norway at that time (Blikra & Nemec ...
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... Mass wasting is often caused by instabilities in the sediment column owing to weak layers and/or rapid sediment accumulation (e.g. Huvenne et al. 2002;Bøe et al. 2004;Haflidason et al. 2004;L'Heureux et al. 2012;Locat et al. 2014;Laberg et al. 2016) and represents wellknown phenomena on glaciated margins that are in this region closely linked with ice-margin dynamics (e.g. Syvitski 1991;Dowdeswell et al. 1998;O Cofaigh et al. 2013a, b). ...
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... Although rock avalanches moving into water bodies are not rare, these are the least documented deposits due to the high-cost involved in the data acquisition. Rock avalanche deposits have been documented in fjords and lakes using either bathymetric or seismic data or a combination of both (e.g., Bøe et al., 2004;Blikra et al., 2006;van Daele et al., 2013;van Zeyl et al., 2015;Bellwald et al. 2016;Lastras et al., 2016;. Rock avalanche deposits under water can have largely varying morphological expressions (Fig. 9). ...
... Rock avalanche deposits under water can have largely varying morphological expressions (Fig. 9). Some deposits can have a pristine morphology like the Tafjord 1934 event in Norway (Bøe et al., 2004) with a proximal debris cone and hummocks arranged in concentric ridges in the more distal part similar to the prehistoric Skorgeurda rock avalanche deposit (Fig. 9A). The deposits of the 1756 Tjellefonna slide (Norway) although only 250 years old (Fig. 9B) (Sandøy et al., 2017) or the prehistoric deposits of the west coast of Bowen Island (Jackson et al., 2014) mark only as separated isolated hummocks within the fjord sediments. ...
Rock avalanches result from the failure of a rock mass that disintegrates and propagates as a granular flow with high mobility. In this contribution we present a process-based definition of the term rock avalanche, clearly distinguishing it against similar and overlapping phenomena. Rock avalanches occur in various environments such as on land, on ice and impacting into the sea or lakes. Related to these environments various secondary effects exist that pose a threat to society such as dams, displacement waves, secondary sediment mass flows, air blasts and others. Systematic rock avalanche hazard mapping is becoming possible today.
... Notwithstanding these issues and caveats, recent years have seen a fruitful flourishing of research directed at the prehistoric evidence for rock-slope adjustment in western Norway (Blikra et al. , 2006Bøe et al. 2004;Aa et al. 2007;Fenton et al. 2011;Longva et al. 2009;Hermanns et al. 2017a). Assisted by geophysical, geodetic, geotechnical and geochronological advances, a programme of mapping terrestrial sites and surveying and coring Norwegian fjords has yielded a record of frequent large-scale RSFs throughout the prehistoric period. ...
... Finally, it is relevant to briefly mention the fjord and lake record of colluvial mass movements in western Norway, which suggests increased frequencies of turbidites, floods, debris flow and snow avalanche activity immediately after deglaciation, with episodic enhanced activity in the Late Holocene (Blikra and Nemec 1993;Bøe et al. 2002Bøe et al. , 2003Bøe et al. , 2004Lepland et al. 2002;Bellwald et al. 2016). These latter pulses of soft sediment reworking have been primarily attributed to in washing during regional climatic irregularities, for example, at 5.6-5.3 ...
The paraglacial framework describes the geomorphological response to glaciation and deglaciation, whereby non-renewable, metastable, glacially conditioned sediment sources are progressively released by a range of nonglacial processes. These include slope failures that directly modify the bedrock topography of mountain landscapes. This chapter synthesises recent research on the paraglacial evolution of western Norway’s mountain rock-slopes, and evaluates the importance of glaciation, deglaciation and associated climatic and non-climatic processes. Following an introduction to the concept of paraglacial landscape change, current understanding of rock-slope responses to deglaciation is outlined, focusing on the spatial distribution, timing, duration and causes of rock-slope failure activity. Preliminary analysis of an inventory of published ages for 49 prehistoric, moderate-large (>103 m3) rock-slope failures (RSFs) indicates that the great majority occurred in the Late Weichselian/Early Holocene transition (~13–9 ka), within 2 ka of deglaciation. Subsequent RSFs were much smaller, though event frequency increased again at 8–7 ka and 5–4 ka BP. The majority of dated RSFs were not directly triggered by deglaciation (debuttressing) but were preconditioned for more than 1000 years after ice withdrawal, until slopes collapsed. It is proposed that the primary causes of failure within 2 ka of ice retreat were stress redistribution, subcritical fracture propagation, with some events possibly triggered by seismic activity. While earthquakes may have triggered renewed failure of rock-slopes in the Late Holocene, it seems likely that permafrost degradation and water supply were locally important. Priority avenues for further research are briefly identified.
... Notwithstanding these issues and caveats, recent years have seen a fruitful flourishing of research directed at the prehistoric evidence for rock-slope adjustment in western Norway (Blikra et al. , 2006Bøe et al. 2004;Aa et al. 2007;Fenton et al. 2011;Longva et al. 2009;Hermanns et al. 2017a). Assisted by geophysical, geodetic, geotechnical and geochronological advances, a programme of mapping terrestrial sites and surveying and coring Norwegian fjords has yielded a record of frequent large-scale RSFs throughout the prehistoric period. ...
... Finally, it is relevant to briefly mention the fjord and lake record of colluvial mass movements in western Norway, which suggests increased frequencies of turbidites, floods, debris flow and snow avalanche activity immediately after deglaciation, with episodic enhanced activity in the Late Holocene (Blikra and Nemec 1993;Bøe et al. 2002Bøe et al. , 2003Bøe et al. , 2004Lepland et al. 2002;Bellwald et al. 2016). These latter pulses of soft sediment reworking have been primarily attributed to in washing during regional climatic irregularities, for example, at 5.6-5.3 ...
The paraglacial framework describes the geomorphological response to glaciation and deglaciation, whereby non-renewable, metastable, glacially conditioned sediment sources are progressively released by a range of nonglacial processes. These include slope failures that directly modify the bedrock topography of mountain landscapes. This chapter synthesises recent research on the paraglacial evolution of western Norway’s mountain rock-slopes, and evaluates the importance of glaciation, deglaciation and associated climatic and non-climatic processes. Following an introduction to the concept of paraglacial landscape change, current understanding of rock-slope responses to deglaciation is outlined, focusing on the spatial distribution, timing, duration and causes of rock-slope failure activity. Preliminary analysis of an inventory of published ages for 49 prehistoric, moderate-large (>10³ m³) rock-slope failures (RSFs) indicates that the great majority occurred in the Late Weichselian/Early Holocene transition (~13–9 ka), within 2 ka of deglaciation. Subsequent RSFs were much smaller, though event frequency increased again at 8–7 ka and 5–4 ka BP. The majority of dated RSFs were not directly triggered by deglaciation (debuttressing) but were preconditioned for more than 1000 years after ice withdrawal, until slopes collapsed. It is proposed that the primary causes of failure within 2 ka of ice retreat were stress redistribution, subcritical fracture propagation, with some events possibly triggered by seismic activity. While earthquakes may have triggered renewed failure of rock-slopes in the Late Holocene, it seems likely that permafrost degradation and water supply were locally important. Priority avenues for further research are briefly identified.
... BP related to the Storegga Slide tsunami (8200 cal. BP) (Bøe et al., 2004a). ...
Frænfjorden, a fjord on the west coast of Norway, has been studied to increase our knowledge of the
environmental effects of submarine tailings placement (STP). Fine-grained tailings consisting primarily of
calcite are disposed of by Omya Hustadmarmor. The dataset, including multibeam echosounder data,
shallow seismic, video data, grab samples and sediment cores, demonstrates that tailings are primarily
deposited in an up to 2 km-wide area with a tailings thickness of up to 20 m. Minor quantities of tailings are
spread outside the STP by tidal currents. Sediment cores show the difference in colour, mineralogy and
grain size between the natural sediments and the tailings. The tailings have a white/grey colour, are very
fine grained, contain high amounts of calcite and have a lower water content than the natural sediments. A
series of multibeam echosounder data from 2013 to 2017 show that deposition of tailings has triggered
several small gravity flows and slides. The tailings within the STP have a low stability compared to the
natural sediments outside the STP because of their fine grain size and higher sensitivity, high slope angles,
high sediment accumulation rates preventing normal consolidation, and loading of tailings causing
overpressure in the underlying sediments.
... BP related to the Storegga Slide tsunami (8200 cal. BP) (Bøe et al., 2004a). ...
... Exposure dating of the backscarp of an active RSD in this study (Gámanjunni-3) suggests displacement initiated between 6.6 and 4.3 ka (Böhme et al. 2019), indicating that rockslides in the area have a long deformation history conditioned by Holocene climatic events. Peaks in Holocene landslide activity have also been attributed to periods of seismic activity due to isostatic uplift (Bøe et al. 2004). The Baltic Shield is generally thought to be aseismic; however, some evidence of neotectonics have been reported in northern Norway. ...
Gravitational forcing of oversteepened rock mass leads to progressive failure, including rupture, creeping, sliding and eventual avalanching of the unstable mass. As the point of rupture initiation typically follows pre-existing structural discontinuities within the rock mass, understanding the structural setting of slopes is necessary for an accurate characterisation of the hazards and estimation of the risk to life and infrastructure. Northern Norway is an alpine region with a high frequency of large rock slope deformations. Inherited structures in the metamorphic bedrock create a recurring pattern of anisotropy, that, given certain valley orientations, causes mass instability. We review the geomorphology, structural mechanics and kinematics of nine deforming rock slopes in Troms County, with the aim of linking styles of deformation. The limits of the unstable rock mass follow either foliation planes, joint planes or inherited faults, depending on the valley aspect, slope angle, foliation dip and proximity to fault structures. We present an updated geotechnical model of the different failure mechanisms, based on the interpretations at each site of the review.
