Structure example: slide E
−6000 −4000 −2000 0
BATHYMETRY
m
Submarine Landslides at the Siberian End of Lomonosov Ridge, Arctic Ocean
Ursula Schlager, Wilfried Jokat und Estella Weigelt (Alfred-Wegener-Institut)
BREMERHAVEN Am Handelshafen 12 27570 Bremerhaven Telefon 0471 4831-0 www.awi.de
DGG2021_A-307
drape*
time needed to accumulate:
4 to 12 Myr
Contact:
References:
glide plane moved volume
left on glide plane
recent mass wastings
missing sediment
Results:
this study
volume [km3] 10-3 10-2 10-1 100 101 102 103
comparison with global landslides[5]:
▻ Submarine landslides with this spatial extent seem common on the ridge.
▻ Submarine landslides occur on both sides of the ridge’s crest. They are 2.1 – 10.2 km wide, 1.7 – 8.2 km long and 125 – 851 m high.
▻ Mobilized volume (0.09-7.58 km3) are at the lower end of global existing submarine landslide sizes
▻ They are draped by 110 - 340 m of sediment that needed 4 - 12 Myr to accumulate.
▻ Smaller deposits within the drape indicate younger mass wasting events.
studied regions
Finneidfjord Canary
BIG’95 Traenadjupet *drape thickness:
110 to 340 m,
sed.-rate ~2.9 cm/kyr
x x’
x x’
x sediment echosounder data x’
multichannel seismic data
[1] Woodgate et al., https://doi.org/10.1016/S0967-0637(00)00091-1 [2] Stein et al., https://doi.org/10.1038/ncomms11148
[3] Stein, https://doi.org/10.2312/BzPM_0688_2015
[4] Kristoffersen, Y., et al., https://doi.org/10.1016/j.margeo.2007.04.012 [5] Canals, M., et al., https://doi.org/10.1016/j.margeo.2004.10.001
The Lomonosov Ridge is a topographic ridge in the Arctic Ocean. It rises several kilometres above the adjacent abyssal plains and, therefore, influences ocean current systems[1] and its shallow parts (<1200m) were affected by glaciogenic processes[2].
Due to difficult sea ice conditions prevailing in the Arctic Ocean sparse high resolution data exists from Lomonosov Ridge to describe its topography and subsurface geology. This contribution presents systematic swath bathymetry, sediment echo sounder and multi- channel seismic data from the Siberian end of the Lomonosov Ridge[3]. The data fully imaged submarine landslides on the ridge’s crest.
Lomonosov
Greenland
Ridge
Canada Basin
Siberia
A F B G
H C
D E
Ursula Schlager
ursula.schlager@awi.de
other
submarine landslides reported by Kristoffersen[4]
width: 2.1 – 10.2 km length: 1.7 – 8.2 km height: 125 – 851 m
mobilized sediment: 0.09 – 7.58 km3 2 km
Geometries of the submarine landslides:
N A
F
Conclusion:
Introduction:
Afen Gebra
Adriatic
Storegga
sediment cut by slide event
1.0 1.2 1.4 1.0
1.5
2.0 twt [s]
twt [s]
New swath bathymetry data with identified submarine landslides A to H:
red lines mark collected seismic reflection & sediment echo-sounder profiles
Amundsen Basin
Makarov Basin
Makarov Basin
Amundsen Basin
Makarov Basin
Makarov Basin
Basin Amundsen
