Extensive marine surveys were performed at Bosphorus-Marmara junction before laying the offshore part of the Hamidabad natural gas pipeline system. This paper introduces IMST's wave measurement programme which is a part of these studies, and explains the assessment of wave-related design parameters of the submarine pipeline crossing the Sea of Marmara.
The present study is a part of a more comprehensive research carried out to assess the oceanographical design parameters of the submarine pipeline laying between Ambarli and Pendik in the Marmara-Bosphorus junction (hereinafter BMJ area), and crossing the Izmit Bay. This submarine pipeline belongs to Hamidabad natural gas pipeline system transporting the Siberian gas of former USSR to Ankara-Turkey (Fig. 1). The entire system in the Turkish territories involves 842 km of pipelines of which a part of 123.4 km-long is offshore. The main characteristics of the system and basic aspects of the design procedure are explained by Akin and Akten (1988). The objective of the study is the ·evaluation of the extreme dynamic loads to which the pipeline may be subjected, in order to assure on-bottom stability during laying and during its operating life. Since it has been found necessary to perform a meteo-oceanographical survey which includes measurement of currents, hydrological parameters, sea levels, waves and collection of meteorological data in order to assess the environmental design parameters for the submarine pipeline project, Institute of Marine Science & Technology, Izmir, Turkey (hereinafter IMST) was requested by BOTAS (Turkish National Pipeline Corporation) to undertake some survey, activities in cooperation with Snamprogetti-Italy. 105 The results of IMST's efforts for the determination of current pattern in the BMJ area have already been introduced by De Filippi, Iovenitti & Akyarh (1986), Arnoy & Akyarh (1990) and Akyarli & Arisoy (1993, 1994).
