DBPapers
DOI: 10.5593/sgem2017/14/S05.060

UXO SEARCH OFF BURGAS: A HIGH RESOLUTION MARINE MAGNETIC SURVEY PRIOR TO THE START OF THE SECOND PHASE HARBOR’S EXPANSION

R.G. Dimitriu, I. Shtirkov, M.B. Barbu
Monday 11 September 2017 by Libadmin2017

References: 17th International Multidisciplinary Scientific GeoConference SGEM 2017, www.sgem.org, SGEM2017 Conference Proceedings, ISBN 978-619-7408-00-3 / ISSN 1314-2704, 29 June - 5 July, 2017, Vol. 17, Issue 14, 475-482 pp, DOI: 10.5593/sgem2017/14/S05.060

ABSTRACT

Over 400,000 shells of different calibers were dumped in Burgas Bay after the end of WWI. The operation, under the coordination of the British forces, was completed without the dumping areas to be clearly mentioned and mapped, allowing us today to assume that they can be anywhere in Burgas Bay. Many other shells were also dumped in the sea at the end of WWII. During the first phase of expansion of Burgas harbor, carried out between 2001 and 2006, a great deal of unexploded ammunition, originating from both WWI and WWII, was discovered and recovered by the dredging operations. Prior to the start of the second expansion phase, the Burgas port authorities ordered a detailed geophysical search to be carried out and cover a 90,000 sq.m surface where dredging activities are planned, aiming to identify sites where items such as UXO, wrecks, pipes, anchors and other metal objects lying on the sea floor and/or buried in shallow sediments could disturb and even endanger the dredging. The high-resolution marine magnetic mapping carried out in August 2016 by a team comprising both Romanian and Bulgarian specialists entirely covered the area of interest. The search was conducted in a totally unfriendly magnetic environment, dominated by huge variations of the total geomagnetic field due to the numerous outcropping or shallow intrusions of Paleozoic and Late Cretaceous ages, to lens of “black sands” with high contents of titanomagnetite minerals, resulted from the physical decomposition of the magmatites and not least to the large pile of steel pipeline sections stored on the neighboring quay. Still, the careful analysis of the magnetic analytic signal as well as the individual analysis of each marine magnetic line were able to highlight the presence of over 75 potential target areas where the presence of UXO-type items, possibly dumped or lost ferrous objects, accumulations of ammunition, etc. on the seabed or shallowly buried in sediments was highly likely. The indexed target sites became subsequently subject for scuba diving inspection which confirmed the existence of ferrous objects within all selected sites and brought to surface over 2,000 artillery shells and other items.

Keywords: Black Sea, Burgas Bay, marine magnetics, UXO detection