New evidence for widespread mass transport on the Northeast Newfoundland Shelf revealed by Olex single-beam echo sounding

Shaw, John; Piper, David J. W.; Skulski, T; Lamplugh, Mike; Craft, Andrew; Roy, Alain

doi:10.1007/s00367-011-0233-3

Cited by 13 publications

(21 citation statements)

References 24 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…2) shows the principal features of the study area noted above, and reveals the difference between the relatively smooth terrain of the Cretaceous-Tertiary bedrock of the banks and the irregular terrain of the older rocks to the west (e.g. Several narrow troughs extend southeast from the basin, notably the trough (F) that Shaw et al (2012) thought was a scar created by submarine sliding. In addition to the three shelf-crossing troughs a smaller trough (B) extending east from St. Anthony Basin extends a short distance onto Belle Isle Bank.…”

Section: Resultsmentioning

confidence: 97%

“…We present a re-analysis of the two areas of complex topography in Notre Dame Trough described by Shaw et al (2012), and also propose that the extent of glaciotectonism on this shelf is much greater than previously thought. We present a re-analysis of the two areas of complex topography in Notre Dame Trough described by Shaw et al (2012), and also propose that the extent of glaciotectonism on this shelf is much greater than previously thought.…”

mentioning

confidence: 74%

“…6A) that is up to 30 m deep, 2.5 km wide, extends 30 km to the northwest from the location of detached block F on Fig. Shaw et al (2012) argued the trough was created by a block of sediment that slid to the northwest on a gradient of~0.3°. Shaw et al (2012) argued the trough was created by a block of sediment that slid to the northwest on a gradient of~0.3°.…”

Section: Notre Dame Trough Glaciotectonismmentioning

confidence: 99%

“…The two channels (A and B on Fig. 6A) interpreted as an area of glaciotectonism by Shaw et al (2012) who argued that the glaciotectonized sediment had been detached on a decollement surface, the top of Cretaceous-Tertiary bedrock. 7.…”

Section: Notre Dame Trough Glaciotectonismmentioning

confidence: 99%

See 3 more Smart Citations

Glacial geomorphology of the Northeast Newfoundland Shelf: ice‐stream switching and widespread glaciotectonics

Shaw

Longva

2017

Boreas

Self Cite

View full text Add to dashboard Cite

Analysis of Olex bathymetry, multibeam sonar and seismic survey data, shows that, perhaps during the mid Pleistocene, grounded ice crossing the Northeast Newfoundland Shelf was topographically steered in Hawke Saddle, occupied a broad trough underlying much of Belle Isle Bank and present‐day Notre Dame Trough, and deposited ~100 m of stacked glacigenic sediment; grounded ice crossed southern Funk Island Bank and occupied Notre Dame Trough. During the Wisconsinan Stage, c. 30 cal. ka BP, flow remained topographically steered in Hawke Saddle, but due to flow switching two convergent ice streams incised the stacked sediments of the earlier phase, creating the modern Notre Dame Trough, and diverging around an erosional remnant near the shelf edge. The ice margin at the Last Glacial Maximum (c. 18 14C ka BP) was at the shelf edge in Trinity Trough but far to the west elsewhere. Retreating ice did not stabilize at fjord mouths, but halted several times within fjords. Shelf morphology was shaped by glaciotectonism. The large tectonized zone on the north flank of Notre Dame Trough was created by the northernmost of the two convergent streams. Glaciotectonism was most widespread in the enclosed St. Anthony Basin, where the Quaternary cover has been stripped away, arrays of composite ridges have formed and sediment blocks have been thrust onto the adjacent bank. A large hill‐hole pair was formed on the east side of the basin, extending onto Belle Isle Bank. A hill‐hole pair on the inner shelf was formed by ice flow from the northwest into Notre Dame Channel. Evidence of widespread glaciotectonism distinguishes this relatively deep shelf from the adjoining, relatively shallow, eastern Canadian shelves, but has strong parallels with parts of the Norwegian continental shelf where methane hydrates maybe played a role in regulating ice‐stream flow.

show abstract

Section: Resultsmentioning

confidence: 97%

mentioning

confidence: 74%

Section: Notre Dame Trough Glaciotectonismmentioning

confidence: 99%

Section: Notre Dame Trough Glaciotectonismmentioning

confidence: 99%

See 2 more Smart Citations

Glacial geomorphology of the Northeast Newfoundland Shelf: ice‐stream switching and widespread glaciotectonics

Shaw

Longva

2017

Boreas

Self Cite

View full text Add to dashboard Cite

show abstract

“…The last decade has seen a marked increase in publications evoking the role of gas in triggering submarine landslides in various settings worldwide (e.g., Best et al 2003;Bünz et al 2005;Shaw et al 2012), accompanied by recent confirmatory evidence in, for example, the western Mediterranean (Berndt et al 2012, Ana submarine landslide complex) and along the Norwegian continental margin (Hill et al 2012, Storegga slide complex). Sultan et al (2012) carried out experiments on natural mudstone samples filled by gas-saturated water under confining pressure, recovered by coring from the continental slope of the Gulf of Guinea at about 20 m below seafloor.…”

Section: Role Of Gasmentioning

confidence: 99%

How to evacuate 10 km3 of mud: saturate with gas and decrease the pressure!

2014

View full text Add to dashboard Cite

The crest of the Absheron anticline in the South Caspian Basin at a few hundred meters below the present seafloor shows a subcircular depression about 8 km in diameter and 200 m deep, bounded by steep edges dipping 15°to 45°into it. The depression and the surrounding series are respectively filled and overlain by a regional mass-transport deposit (MTD) 150 m thick outside the depression and 300 m thick inside, composed mostly of extensional blocks. Geometric and stratigraphic analyses indicate that 150 m of initially deposited sediment were removed from a closed area after burial. Seismic evidence of shallow gas accumulations below the crater-like feature suggests that gas likely played a significant role in its development. The model proposed for the emplacement of the crater is that the gas-bearing cover of a shallow gas reservoir underwent exsolution when its overburden thinned during an episode of extensional slope failure. This resulted in loss of resistance to shear and evacuation of the gas-bearing sediment, likely at the shearing base of the failed mass. This evacuation feature is considered an example where the presence of gas locally governs the morphology of an MTD. The interpreted process shows a positive feedback between slope failure and loss of strength at the base of the resulting MTD.

show abstract

Freshening of near-bottom waters in Lake Baikal triggered by the Mw6.2 Kultuk earthquake of August 2008

et al. 2012

View full text Add to dashboard Cite

New evidence for widespread mass transport on the Northeast Newfoundland Shelf revealed by Olex single-beam echo sounding

Cited by 13 publications

References 24 publications

Glacial geomorphology of the Northeast Newfoundland Shelf: ice‐stream switching and widespread glaciotectonics

Glacial geomorphology of the Northeast Newfoundland Shelf: ice‐stream switching and widespread glaciotectonics

How to evacuate 10 km3 of mud: saturate with gas and decrease the pressure!

Freshening of near-bottom waters in Lake Baikal triggered by the Mw6.2 Kultuk earthquake of August 2008

Contact Info

Product

Resources

About