# Satellite-Derived Bathymetry for Selected Shallow Maltee Coastal Zones
## 1 Introduction
Therefore, despite having a lower resolution, SDB mitigates the limitations inherent by the conventional in situ acoustic and optical methods [21]. Recent technological developments in SDB provide opportunities for new methodologies that can reveal the bathymetry of uncharted coastal areas and facilitate the investigation of seabed morphology changes. In Europe, bathymetric data are either considerably antiquated or not accessible [9]. Hence, modern techniques that integrate both in situ data and satellite-derived imagery can aid in the comprehensive mapping of the shallow coastal characteristics in Europe [22]. The primary objective of the current study is to compute the bathymetry of two coastal regions in the Maltese Islands through the utilisation of remote sensing satellite data, together with in situ lidar and sonar technologies. The Maltese Islands are located in the centre of the Mediterranean Sea between Sicily and the North African coast and are made up of three principal islands, Malta, Gozo, and Comino together with a number of islets and rocks, having a total land surface area of 316.75 square kilometres [23]. The Maltese archipelago straddles the northern rim of the Pantelleria rift, a graben system that has been active since the late Miocene up to present times, traversing the wide shelf platform connecting Europe and Africa [24]. The bathymetry bordering the eastern flank of the Maltese Islands is composed of a wide planar continental shelf, bounded by a linear excarpment aligned parallel to the coast. On the other hand, the western side of the islands consists of a narrow shelf, ranging a few hundred metres away from the coast encompassing steep scarps around 100 m high [25]. Two beaches located along the western side of the Maltese Islands are Golden Bay and Ghajn Tuffieha Bay (Figure 1). Golden Bay epitomises a typical Maltese sandy embayment as it is found at a bottom of a valley. This is a pocket beach and experiences sediment runoff from the surrounding natural regions. The sandy beach is composed mainly of pale yellow-brown sand derived from the Globigerina Limestone-dominated cliffs [26]. Located between Ras il-Wahx in the north and the Ghajn Tuffieha headland in the south, this beach stretches approximately over 200 m and varies in width between 25 m and 100 m. Ghajn Tuffieha Bay (Riviera) is composed of a pocket beach situated between two high rocky headlands, the Ghajn Tuffieha headland and the Qarraba headland, along Malta's northwestern coast. This area experiences vigorous waves coming from the west and northwest which erode the base of the coastal slopes consequently resulting in mass movement processes and slope forms leading to sediment movement [27]. Riviera beach is 300 m in length and has a maximum width of 25 m and is composed mainly of pale orange-brown medium sand with gravel towards the south. The beach sediment is mostly derived from the Upper Coralline Limestone erosion of the flanking headlands as well as erosion from the mudslide toes behind the beach [27]. These two beaches have been chosen as both experience similar anthropogenic activities as well as natural process such as sediment transport, due to both being closed pocket beaches situated along the northwestern coast of Malta. This paper aims to make use of several bathymetric mapping techniques to understand the bathymetric profile of these two pocket beaches during differing times of the year.