SWATH BATHYMTERY MAPPING FOR SUBMERGED RIVERS IDENTIFICATION AND ITS BENEFIT

World Delta Summit November,23rd 2011 Athlete Century

M. Hasanudin, Priyadi D.S. *), Teguh F. A. **)*) P2O- LIPI**) Bakosurtanal

Introduction Sea levels have fluctuated throughout geological time,

periodically flooding or draining the world’s coastal plains Tectonic caused uplift, slope and subsidence topography Last glaciations that occurred about 18000 years ago to

6000 y.a, sea level was increasing up to 140 m rivers that had elevation below 140 m become drown and lies under recent sea level

This rivers was called drown rivers or drowned river valley

In Indonesia, drowned rivers were called Mollengraf rivers (Dutch Scientiest, 1922)

(ongkosongo, 2010)

Isotop Oxygen 18 recorded during last 140,000 years in foraminifers’ plankton of bore RC17-177 and sea level estimation base on limestone terraces in New Guinea (Shackleton, 1987).

Ancient channel reconstruction base on bathymetry showed the existence of rivers flow in Sunda Shelf (Kuenen. op.cit Emery et.al., 1972).

Objective

To Identify the submerged Rivers in Indonesia using Swath Bathymetry and Its Benefit

Method Swath Bathymetry Multibeam Echosounder SIMRAD EM1002 RV. Baruna Jaya VIII ELAC 1050D RV. Baruna Jaya IV Data Acquisition: 1. Seafloor Information System (SIS)2. Hydrostar Data Processing1. Neptune2. CARIS3. CFloor

Result

Morotai Found two submerged rivers The southern river was identified about 20 km long, about

600 m to 1000 m wide, and NW-SE orientation. The northern river was identified about 13 km long, about 600 to 700 m wide and NW-SE orientation. In

South River of Morotai The southern river was

identified about 20 km long, about 600 m to 1000 m wide, and NW-SE orientation.

North River of Morotai The northern river

was identified about 13 km long, about 600 to 700 m wide and NW-SE orientation

South Kalimantan Drowned river valley was

identified about 62 km long, about 4000 m to 5000 m wide, and NW-SE orientation.

GorontaloRiver was identified about 3 km long, about 300 to 700 m wide and NW-SE orientation

North Kangean

Benefit of Submerged Rivers Mapping

evidence of sub merged terrestrial environment, to estimate the paleo-hydrology; ancient civilization and archeology, estimate the secondary economical mineral

deposit.

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