Sedimentology and geomorphology of a large tsunamigenic landslide, Taan Fiord, Alaska

Dufresne, Anja; Geertsema, Marten; Shugar, Dan H.; Koppes, Michèle; Higman, Bretwood; Haeussler, Peter J.; Stark, C. P.; Venditti, Jeremy G.; Bonno, Doug; Larsen, C. F.; Gulick, Sean P. S.; McCall, N.; Walton, M. A. L.; Loso, Michael G.; Willis, M. J.

doi:10.1016/j.sedgeo.2017.10.004

Cited by 52 publications

(43 citation statements)

References 50 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Regardless, as the volume of the blocky slide material (unit BL) is 128% of the volume of the material that entered the fjord, and it seems certain that the blocky unit consists dominantly of Yakataga Formation slump blocks with a smaller percentage of fjordbottom sediment. The proximal part of the submarine landslide deposit has numerous large blocks (greater than tens of meters across) as seen on the bathymetry data (Figure 4; see line on Figure 13b; see also Dufresne et al, 2017, Figure 6), but the distal part of the unit seems to have no large blocks, although it is in the same seismic-stratigraphic unit, and thus, perhaps there was more fjord-bottom sediment incorporated into the distal deposit. The amplitude of the chaotic reflections within unit BL decreases near the toe of the slide, suggesting a lower acoustic impedance contrast and thus lower density, which supports this interpretation.…”

Section: /2018jf004608mentioning

confidence: 81%

“…These blocks are 10 to 20 m; they are aligned as a train in the downslope direction and perhaps were deposited as a group. In general, the long axes of blocks approach orientations either perpendicular or parallel to movement, with the highest concentration of parallel blocks along the slide margins (see Figure 6 in Dufresne et al, ). The main suite of parallel‐to‐movement‐oriented blocks is on the fjord edge where the least amount of shortening would be expected.…”

Section: Resultsmentioning

confidence: 99%

“…An average sediment thickness of 5 ± 1 m was estimated from observations at the margins of the glacier. The block on the Hoof Hill fan on the east side of the fjord is remarkable in that it demonstrates that sediment transited the entire 1.5‐km width of the fjord during the landslide (Dufresne et al, ; Higman et al, ). This block became known as Edgar and is a notable postlandslide landmark visible from around the northern end of the fjord.…”

Section: Resultsmentioning

confidence: 99%

“…Satellite images soon after the event also identified the slide, direction of travel, deposition in the fjord, and significant tsunami runup in Taan Fiord. An overview of the Taan Fiord landslide and tsunami is given by Higman et al (2018) and documents tsunami runup to 193 m. Dufresne et al (2017) described the subaerial landslide deposits. A model of the subaerial-induced tsunami generation was given by George et al (2017) with no input from ground-based observations.…”

Section: /2018jf004608mentioning

confidence: 99%

“…The landslide deposit lies above and below sea level (Dufresne et al, 2017;Higman et al, 2018). The subaerial part of the deposit includes the volume within the landslide scar, discussed above, as well as material on the toe of the Tyndall Glacier and the hummocks on the east side of the fjord and on the Hoof Hill fan (Table 1; Figure 7).…”

Section: Landslide Depositmentioning

confidence: 99%

See 4 more Smart Citations

Submarine Deposition of a Subaerial Landslide in Taan Fiord, Alaska

et al. 2018

Self Cite

View full text Add to dashboard Cite

A large subaerial landslide entered Taan Fiord, Alaska, on 17 October 2015 producing a tsunami with runup to 193 m. We use LiDAR data to show the slide volume to be 76 + 3/−4 million cubic meters and that 51,000,000 m3 entered Taan Fiord. In 2016, we mapped the fjord with multibeam bathymetry and high‐resolution seismic data. Landslide and postlandslide deposits extend 6 km downfjord, are up to 70 ± 11 m thick, and have a total volume of ~147,000,000 m3. Seismic data image a blocky landslide unit and two units deposited immediately after the landslide. The blocky landslide unit is ~65,000,000 m3. We infer it consists dominantly of subaerially derived material and secondarily of fjord floor sediment. The overlying units are likely megaturbidites presumably deposited within minutes to days after the landslide. We infer that these deposits dominantly consist of fjord floor material mobilized and suspended as the slide entered and traveled downfjord. The lower postlandslide unit is up to 35 ± 6 m thick, and the upper unit is up to 12 ± 3 m thick. These deposits are distinctive and will leave a lasting record of the event. This subaerial‐to‐submarine landslide deposit is distinct from other submarine landslide deposits studied in Alaskan fjords because it has a much greater thickness, larger and more angular blocks, distinctive postlandslide megaturbidites, and a higher‐amplitude acoustic signature of the blocky deposit. The tight constraints on the landslide source and deposit volumes, topography, bathymetry, and tsunami runup heights and flow directions should make this a benchmark site for landslide‐tsunami models.

show abstract

Section: /2018jf004608mentioning

confidence: 81%

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Section: /2018jf004608mentioning

confidence: 99%

Section: Landslide Depositmentioning

confidence: 99%

See 3 more Smart Citations

Submarine Deposition of a Subaerial Landslide in Taan Fiord, Alaska

et al. 2018

Self Cite

View full text Add to dashboard Cite

show abstract

Transferability of a calibrated numerical model of rock avalanche run‐out: Application to 20 rock avalanches on the Nuussuaq Peninsula, West Greenland

Benjamin

Rosser

Dunning

et al. 2018

Earth Surf Processes Landf

View full text Add to dashboard Cite

Long run‐out rock avalanches are one of the most hazardous geomorphic processes, and risk assessments of the threat they pose are often reliant on numerical modelling of their potential run‐out distance. The development of such models requires a thorough understanding of past flow behaviour inferred from deposits emplaced by previous events. Despite this, few records exist of multiple rock avalanches that occurred in conditions sufficiently consistent to develop a set of more generalised, and hence transferrable, rules. We conduct field and imagery‐based mapping and use numerical modelling to investigate the emplacement of 20 adjacent rock avalanches on the southern flanks of the Nuussuaq peninsula, West Greenland. The rock avalanches run out towards the Vaigat Strait, and are sourced from a range of coastal mountains of relatively uniform geology. We calibrate a three‐dimensional continuum dynamic flow code, VolcFlow, with data from a modern, well‐constrained event that occurred at Paatuut (ad 2000). The best‐fit model assumes a constant retarding stress with a collisional stress coefficient, simulating run‐out to within ±0.3% of that observed. This calibration was then used to model the emplacement of deposits from five other neighbouring rock avalanches before simulating the general characteristics of a further 14 rock avalanche deposits on simplified topography. Our findings illustrate that a single calibration of VolcFlow can account for the observed deposit morphology of a uniquely large collection of rock avalanche deposits, emplaced by a series of events spanning a large volume range. Although the prevailing approach of tuning models to a specific case may be useful for detailed back‐analysis of that event, we show that more generally applied models, even using a single pair of rheological parameters, can be used to model potential rock avalanches of varied volumes in a region and, therefore, to assess the risks that they pose. © 2018 John Wiley & Sons, Ltd.

show abstract

Impact of an 0.2 km³ Rock Avalanche on Lake Eibsee (Bavarian Alps, Germany) – Part I: Reconstruction of the paleolake and Effects of the Impact

Knapp

Mamot

Lempe

et al. 2020

Earth Surf Processes Landf

View full text Add to dashboard Cite

Rock avalanches destroy and reshape landscapes in only a few minutes and are among the most hazardous processes on Earth. The surface morphology of rock avalanche deposits and the interaction with the underlying material are crucial for runout properties and reach. Water within the travel path is displaced, producing large impact waves and reducing friction, leading to long runouts. We hypothesize that the 0.2 km3 Holocene Eibsee rock avalanche from Mount Zugspitze in the Bavarian Alps overran and destroyed Paleolake Eibsee and left a unique sedimentological legacy of processes active during the landslide. We captured 9.5 km of electrical resistivity tomography (ERT) profiles across the rock avalanche deposits, with up to 120 m penetration depth and more than 34 000 datum points. The ERT profiles reveal up to ~50 m thick landslide debris, locally covering up to ~30 m of rock debris with entrained fine‐grained sediments on top of isolated remnants of decametre‐wide paleolake sediments. The ERT profiles allow us to infer processes involved in the interaction of the rock avalanche with bedrock, lake sediments, and morainal sediments, including shearing, bulging, and bulldozing. Complementary data from drilling, a gravel pit exposure, laboratory tests, and geomorphic features were used for ERT calibration. Sediments overrun by the rock avalanche show water‐escape structures. Based on all of these datasets, we reconstructed both position and size of the paleolake prior to the catastrophic event. Our reconstruction of the event contributes to process an understanding of the rock avalanche and future modelling and hazard assessment. Here we show how integrated geomorphic, geophysical, and sedimentological approaches can provide detailed insights into the impact of a rock avalanche on a lake. © 2020 The Authors. Earth Surface Processes and Landforms published by John Wiley & Sons Ltd

show abstract

Sedimentology and geomorphology of a large tsunamigenic landslide, Taan Fiord, Alaska

Cited by 52 publications

References 50 publications

Submarine Deposition of a Subaerial Landslide in Taan Fiord, Alaska

Submarine Deposition of a Subaerial Landslide in Taan Fiord, Alaska

Transferability of a calibrated numerical model of rock avalanche run‐out: Application to 20 rock avalanches on the Nuussuaq Peninsula, West Greenland

Impact of an 0.2 km³ Rock Avalanche on Lake Eibsee (Bavarian Alps, Germany) – Part I: Reconstruction of the paleolake and Effects of the Impact

Contact Info

Product

Resources

About

Sedimentology and geomorphology of a large tsunamigenic landslide, Taan Fiord, Alaska

Cited by 52 publications

References 50 publications

Submarine Deposition of a Subaerial Landslide in Taan Fiord, Alaska

Submarine Deposition of a Subaerial Landslide in Taan Fiord, Alaska

Transferability of a calibrated numerical model of rock avalanche run‐out: Application to 20 rock avalanches on the Nuussuaq Peninsula, West Greenland

Impact of an 0.2 km3 Rock Avalanche on Lake Eibsee (Bavarian Alps, Germany) – Part I: Reconstruction of the paleolake and Effects of the Impact

Contact Info

Product

Resources

About

Impact of an 0.2 km³ Rock Avalanche on Lake Eibsee (Bavarian Alps, Germany) – Part I: Reconstruction of the paleolake and Effects of the Impact