There are thirty valleys formed by groundwater on Malta and Gozo, with the most prominent examples located in Mgarr (including Gnejna Valley), Mellieha and Nadur. There are an additional twenty three such valleys on the seafloor, mostly located offshore of the north- eastern coast of Malta and Gozo. There are a number of important implications associated with this discovery. First, this is the first time that groundwater seepage has been demonstrated to form valleys in rock. These valleys therefore deserve additional protection in view of their uniqueness.
Secondly, these valleys can be used to reconstruct environmental and water conditions in the past, which is very useful in places where the geological record is poor, such as in desert environments or potentially even Mars, where similar valleys have been documented.
Thirdly, the scientists show that the valleys are retreating at a rate of about 2 cm per year in the form of block landslides. This is an important consideration when assessing the hazard associated to these valleys, especially for owners of fields located above or within the valleys.