Properties of Mass-Transport Deposits as Inferred from Dynamic Modeling of Subaqueous Mass Wasting: A Short Review
Published:January 01, 2011
Fabio V. De Blasio, Anders Elverhøi, 2011. "Properties of Mass-Transport Deposits as Inferred from Dynamic Modeling of Subaqueous Mass Wasting: A Short Review", Mass-Transport Deposits in Deepwater Settings, R. Craig Shipp, Paul Weimer, Henry W. Posamentier
Download citation file:
We discuss recent attempts to investigate some features of mass-transport deposits (MTDs) from a dynamic and numerical modeling viewpoint. We selected some study examples, such as the problem of the large mobility of submarine mass wasting, emplacement of erratic blocks, and possible change of rheologic properties during flow. Some lubrication mechanisms are needed to explain mobility of submarine slides, and in this respect we discuss hydroplaning and shear wetting models. We show that hydroplaning could explain several features of small, cohesive debris flows such as the Finneidfjord landslide in Norway, and emplacement of outrunner blocks in the Nigerian basin or the Faeroe Islands. However, larger submarine slides usually scour the sea bottom and need a much higher velocity to hydroplane. For this reason, additional mechanisms must be invoked to explain dynamics of the largest submarine slides. In relation to the giant Storegga slide off Norway, we discuss possible effect of the high shear rates due to friction with ambient water on the surface of a submarine slide. This may result in strength loss of sediments and remolding, with consequent increase in mobility. At times, a mobile debris flow may raft huge blocks along its path, providing a further clue as to velocity, impact forces, and block resistance. In this respect, we discuss a couple of examples from the Arctic Sea and the Balearic Basin. We argue that a better understanding of geometry and sedimentologic characteristics of MTDs will require more dedicated studies on submarine slide dynamics in the subaqueous environment. In turn, this should be achieved with an integrated approach between field data, experimental activity, and numerical simulations.
Figures & Tables
Mass-Transport Deposits in Deepwater Settings
Historically, submarine-mass failures or mass-transport deposits have been a focus of increasingly intense investigation by academic institutions particularly during the last decade, though they received much less attention by geoscientists in the energy industry. With recent interest in expanding petroleum exploration and production into deeper water depths globally and more widespread availability of high-quality data sets, mass-transport deposits are now recognized as a major component of most deep-water settings. This recognition has lead to the realization that many aspects of these deposits are still unknown or poorly understood. This volume contains twenty-three papers that address a number of topics critical to further understanding mass-transport deposits. These topics include general overviews of these deposits, depositional settings on the seafloor and in the near-subsurface interval, geohazard concerns, descriptive outcrops, integrated outcrop and seismic data/seismic forward modeling, petroleum reservoirs, and case studies on several associated topics. This volume will appeal to a broad cross section of geoscientists and geotechnical engineers, who are interested in this rapidly expanding field. The selection of papers in this volume reflects a growing trend towards a more diverse blend of disciplines and topics, covered in the study of mass-transport deposits.