A GIS database of large boulders along the north-eastern coast of Malta

Abstract

This study aims to produce GIS maps of identified boulders on the northeastern coast of Malta and propose a plausible hypothesis behind how these boulders might have been deposited onto their current positions on the shore; whether the results of storm waves or historical tsunamis. The maps produced show the relationship of the boulders with their estimated masses, their distances from the shoreline and the estimated required wave height for them to be deposited. The estimated wave height requirement for each boulder to be deposited is calculated using some hydrodynamic equations which involve two different theories; boulders entrained into the flow of the waves and boulders which slide on the shore platform before reaching their current inland location. Additionally, the hydrodynamic equations used also involve some specific assumptions. The findings of this study show that these boulders might have originated from previous storms between 1958 and 2002. Additionally, these boulders might have also been deposited from historical tsunamis, back in 1693 and 1908. This study only accounts for whether or not, the particular storm or tsunami could have deposited the boulders to their particular positions by comparing wave heights. In order for one to identify the exact event, by date, responsible for the deposition of these boulders, further detailed analysis with the use of radiocarbon dating should be used.