| Autor: |
J.M. Woodside, Alexander V. Volgin |
| Rok vydání: |
1996 |
| Předmět: |
|
| Zdroj: |
Marine Geology. 132:39-53 |
| ISSN: |
0025-3227 |
| DOI: |
10.1016/0025-3227(95)00152-2 |
| Popis: |
A survey of a large field of mud diapirs on the Mediterranean Ridge south of Crete was carried out using both OKEAN (9.5 kHz) and MAK-1M (30 kHz) sidescan sonar systems during Leg-2 of the Third Training Through Research cruise of R/V Gelendzhik in June and July, 1993. High backscatter intensities were recorded by both systems to different degrees over the mud diapirs and their immediate surroundings. Causes of variations in the backscatter intensity are considered to be the spatial distribution of mud breccia associated with the mud domes (both the burial depth of the mud breccia beneath hemipelagic drape and its areal extent) and its physical properties, along with contributions from seafloor roughness and the topography of the mud domes. Significant sources of volume scattering of the sidescan sonar sound signal are considered to be mud breccia inhomogeneities represented by millimetric/centimetric clasts of various lithologies and free gas bubbles distributed through the mud matrix. A good general relationship is established between these sources and the observed backscatter variations through analysis of ground truth data from core samples, with 5 kHz deep-tow subbottom profiler records and seafloor video observations as well as the sidescan sonar records; but a fully quantitative assessment of this relationship would require acoustic modelling and additional ground truth data. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
|
Full Text from ScienceDirect