Karakteristik Morfologi Dasar Laut dan Hubungannya dengan Ketebalan Sedimen dan Kecepatan Arus di Selat Flores, Selat Lamakera, Selat Boling, dan Selat Alor

<strong>Characteristics of Sea Bottom Morphology and Their Relationships with Sediment Thickness and Current Speed in the Straits of Flores, Lamakera, Boling, and Alor. </strong> The morphology of the seabed of a strait may affect sedimentary deposits and current speeds in the strait. The Straits of Flores, Lamakera, Boling, and Alor connect the Flores Sea and Savu Sea in East Nusa Tenggara Province. This study aimed to determine the characteristics of seabed morphology and its relation to sediment thickness and current speed in the straits. Single Beam Echosounder and SubBottom Profiler were used to measure depth of waters and subsurface. The results showed that the seabed of the Flores Strait was basin-shaped at a depth of about 250 m, while the seabed at the connections between the Straits of Boling, Lamakera, and Alor was a ridge leading to the Flores Sea and Savu Sea with depths up to 3,000 m. The thickness of the sedimentary sediments in the Flores Strait reached 50 m, while in the Straits of Boling, Lamakera, and Alor sedimentary deposits were not visible. In the Flores Strait which was characterized by narrow strait, the current speed ranged from 0.3 to 3.8 m/s. The descriptions of subsurface conditions in these straits can be used for navigation of ships that will cross the straits, especially vessels of more than 2,000 tons. The narrow strait morphology causes the mass of water in this region to have a high current speed. Therefore, the sedimentation occurs only in the Flores Strait due to its basin-shaped seabed.

Remote sensing for underwater archaeology: case stud-ies from Greece and Eastern Mediterranean

Modern underwater remote sensing technology introduces many advantages that extend the range of conventional diving work providing the means to survey in a detailed and systematic fashion large seafloor area. There are two general approaches regarding the application of these techniques in underwater archaeology; they are being increasingly used to identify, locate and map (i) ancient and historical shipwrecks lying on the seafloor or partly buried in it and (ii) the coastal palaeogeogra-phy and thus submerged sites of archaeological interest (submerged ancient cities, settlements, ports and man-made structures). The underwater remote sensing techniques most commonly applied to underwater archaeology employ: (i) single and multi-beam echosounders (ii) side scan sonar (acousting imaging), (iii) laser line scan (optical imaging) (iv) subbottom profiler, (v) marine magne-tometer and (vi) undersea vehicles. The objectives of this paper are twofold: (i) to present the results of remote sensing surveys that carried out at sites of archaeological and historical interest, in Greece (Dokos Island, ancient harbour of Kyllene and Navarino Bay whereas a historical naval Battle took place) and in Eastern Mediterranean Sea (Alexandria Egypt and Mazotos shipwreck Cyprus), and (ii) to prove the applicability of remote sensing techniques in underwater archaeology showing that a combination of these can be a very effective tool.