Morphometry, limnology, hydrology and sedimentology of maar lakes in East Java, Indonesia

In the volcanic arc of Java, Indonesia, maar lakes exist around the Lamongan-Tarub stratovolcano and north of Tengger Caldera in East Java. Geological, morphometrical, hydrological, limnological, sedimentological and geochemical data are presented from the maar lakes Ranu Agung, Ranu Lading, Ranu Segaran and Ranu Klindungan. Lake sediments are discussed with respect to their potential as climate archives. Severe problems for the maar lakes resulting from high population pressure and intense agriculture are highlighted.