Fresh water is present in the form of shallow groundwater. Lihiman has a land area of approximately 29 hectares, about the same size as Baguan. The circular portion at the northeast end was built up by the extrusion of a mud volcano. Compared to those of Boan and Bakkungan, the mud extrusion is relatively more violent and has created a 20-m crater at the hilly portion. Extrusion activity is said to be accompanied by tremors.
Extruded material contains a mixture of mud and angular boulders.
Dried mud at the top of the agoho trees rimming the crater shows the high pressure at which mud is vented. Due to the huge volume of material discharged, a drainage way has been carved on the northern hill slope leading to the sea. A sandy beach dominates the southern and western shoreline. Siltation at the northern shoreline is evident. Gray silt deposit, the same color as the mud coming from the mud volcano, is observed in the foreshore.