Underwater stationary targets are objects under the water that can¡¦t move autonomously. Apparatus feasible for detecting underwater stationary targets includes: optics, acoustics and geophysical instruments.
The objective of this study was to investigate engineering characteristics of the battleship reef and other reefs deployed off Hai-Kou, Ping-Dong County, by the application of an integrated underwater surveying system. A total of four surveys were conducted. i.e., the 14th of April 2004, the 20th of July 2006, the 3rd of Mar. 2007 and the 30th of Oct. 2007. The investigation were completed using primarily the sidescan soner, along with other auxiliaries such as magnetometer and single beam echo sounder. Based on a mutual consideration of the results of the first survey in April 2004, the battleship on the seafloor was identified as Jong-Rong battleship. The battleship was sitting on the seabed in an upright condition at depths of 32 to 42m below the sea surface. A chain cable was catenated from the stern of the battleship down to the seabed. In addition, a large number of cubic artificial reefs were spreaded around.
A comparision of results obtained during the first and the third survey indicated that the battleship was undergone a displacement of 250m. The significant displacement of the battleship was correlated with a medium magnitude typhoon passed by on the 3rd of Dec. 2004 and the 17th of May 2006 (i.e., Nanmadol and Chanchu Typhoon). The second and the third survey indicated that the battleship was¡¦t moved by earthquake on the 26th of Dec. 2006 (i.e., Herng Chuen earthquake)with magnitude of seven. A comparison of the third and the fourth surveys suggested that the battleship¡¦s bow was moved to the north for an extra 20m. This movement is correlated with a typhoon passed by in Aug. 2007(i.e., Pabuk Typhoon). However, a detailed investigation of the sonographs indicated that there are very limited relative displacement between the battleship and cement artificial reefs that scattered around the battleship. Therefore, further investigations are needed to verify this tautative conclusion.
Based on sidescan soner imagery collected in four surveys between 2004 and 2007. the location of various type of artifical reefs at Hai-Kou artifical reef site were investigated. Except the battleship reef, all the orther types of reefs which include steel reef, electric-pole reef and cement reef were not displaced by either typhoon or earthquake. Under the influence of typhoon waves, the battleship reef was displaced for a distance of 250m.
| Identifer | oai:union.ndltd.org:NSYSU/oai:NSYSU:etd-0902108-194609 |
| Date | 02 September 2008 |
| Creators | Chen, Tai-yueh |
| Contributors | Cai-cheng Huang, Dong-jie Li, Wen-miin Tian |
| Publisher | NSYSU |
| Source Sets | NSYSU Electronic Thesis and Dissertation Archive |
| Language | Cholon |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0902108-194609 |
| Rights | unrestricted, Copyright information available at source archive |
Page generated in 0.0023 seconds