The most remarkable phenomenon, which is observed at the Lamongan, which apart from it, in whole Jawa is never seen at no single volcano, is the amount of small lakes which are situated on several distances from each other, but are surrounding the cone volcano in a line following each other in a wide circle.
The significant change in seismic activity for an active volcano is closely related to the stage of volcanic activity. Even in the dormancy period, the observation of seicmic activity of a particular volcano is very important to evaluate the status and to anticipate the future behavior. The Volcanological Survey of Indonesia installed triparti- te instruments at the Anak Krakatau and Sertung…