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It broke from the eastern or windward side of Oʻahu, Hawaiʻi between 1 and 1.5 million years ago and lies in the Pacific Ocean north of Molokaʻi. [1] [2] At the time of collapse, Oʻahu was part of the conglomerate island Maui Nui, elevated above the ocean from lower sea levels, and contained the Koʻolau Volcano. The eastern half of the ...
Furthermore, the ability to flow may also be dependent upon the amount of energy transferred to the falling sediment throughout the failure event. Often large landslides on the continental margin are complicated and components of slide, debris flow and turbidity current may all be apparent when examining the remains of a submarine landslide.
The earliest phase of the seaway began in the mid-Cretaceous when an arm of the Arctic Ocean transgressed south over western North America; this formed the Mowry Sea, so named for the Mowry Shale, an organic-rich rock formation. [1] In the south, the Gulf of Mexico was originally an extension of the Tethys Ocean. In time, the southern embayment ...
Most flows are liquefied, and many references to fluidized sediment gravity flows are in fact incorrect and actually refer to liquefied flows. [5] Debris flow or mudflow – Grains are supported by the strength and buoyancy of the matrix. Mudflows and debris flows have cohesive strength, which makes their behavior difficult to predict using the ...
A buoyant sediment-laden river plume can induce a secondary turbidity current on the ocean floor by the process of convective sedimentation. [24] [4] Sediment in the initially buoyant hypopycnal flow accumulates at the base of the surface flow, [25] so that the dense lower boundary become unstable. The resulting convective sedimentation leads ...
It has been suggested that, as the Earth's lithospheric plates moved over the mantle plume (the Iceland plume), the plume had earlier produced the Viluy Traps to the east, then the Siberian Traps in the Permian and Triassic periods, and later going on to produce volcanic activity on the floor of the Arctic Ocean in the Jurassic and Cretaceous ...
This condition occurs in many environments aside from simply the deep ocean, where turbidites are particularly well represented. Lahars on the side of volcanoes, mudslides and pyroclastic flows all create density-based flow situations and, especially in the latter, can create sequences which are strikingly similar to turbidites.
Numerous species of benthic foraminifera became extinct during the event, presumably because they depend on organic debris for nutrients, while biomass in the ocean is thought to have decreased. As the marine microbiota recovered, it is thought that increased speciation of benthic foraminifera resulted from the increase in food sources. [ 35 ]