Central Java ash makes Central Java highly fertile agriculture land. Paddy fields are extensive, except in the southeastern Gunung Kidul region partly due to the high concentration of limestone and its location in a rain shadow from the prevailing weather. The largest rivers are the Serayu in the west, which empties into the Indian Ocean, and the Solo which flows into East Java. On the eve of the World War II in 1942, Central Java was subdivided into 7 residencies (Dutch "residentie" or plural "residenties", Javanese "karésiḍènan" or "karésidhènan") which corresponded more or less with the main regions of this area. These
Ryukyu Trench Ryukyu Trench The , also called Nansei-Shotō Trench, is a 1398 km (868 mi) long oceanic trench located along the southeastern edge of Japan's Ryukyu Islands in the Philippine Sea in the Pacific Ocean, between northeastern Taiwan and southern Japan. The trench has a maximum depth of 7460 m (24,476 ft). The trench is the result of oceanic crust of the Philippine Plate obliquely subducting beneath the continental crust of the Eurasian Plate at a rate of approximately 52 mm/yr . In conjunction with the adjacent Nankai Trough to the northeast, subduction of the Philippine plate has produced 34 volcanoes.