Review of the long-term coastal evolution of North Oman - subsidence versus uplift

The paper evaluates the Quaternary coastal evolution of Oman. The plate tectonic setting and the Quaternary climate evolution are reviewed and identified as key factors of coastal evolution. The Arabian Plate is characterised by a northward movement forming a continent-continent collision zone in the west; oceanic crust is being subducted in the east forming the Makran Subduction Zone. Consequently differential land movement is observable in Oman. We digitised the coastline in a very high resolution and computed the ratio of the length of the coastline between two points and the shortest distance between these. This Coast Indentation Index was implemented in a geographic information system. The computed ratio is a semi-quantitative proxy for the equilibrium of the coastline with respect to the littoral forces acting on it. It is demonstrated that the coast within the Musandam Governorate in the north of Oman is subsiding, whereas the coastlines in the Ash Sharqiyah region in the east are being uplifted. The quantification of the differential land movement is seen as an important input factor for a sustainable coastal zone management. It is concluded that individual tectonic blocks move relative to each other. These neotectonic movements are most likely related to seismicity.