| Summary: | Semarang Urban areas are underlined by tertiary rock of sandstone and plastic mudstone. Those tertiary rock
are overlaid unconformly by classic sediment of Old Ungaran Volcano deposited in the late Pleistocene (22.150 years
old). Fault and joint structure occurrence that is involving those volcanic classic rock and river terrace reaching 75 m
above river bed indicate that the Semarang Urban Areas have been experiencing neo-tectonic. The tectonic activity has
uplifted the southern hilly area ofBanyumanik Mijen hills with average uplift rate of 0.4 em/year. On the contrary,
subsidence has been taking place within the north part of Semarang Urban areas followed by consolidation and
compaction of young sediment material. The subsidence rate is predicted at about 3 -10 em/year. The tectonic process
that caused uplift at southern and subsidence at northern part is controlled by Northwest - Southeast fault structure.
Those geological setting has bringing about soil creep and landslide hazard in the hilly areas and tide flood (rob) in
the north areas.
Keywords: Semarang urban area, geological structure, mismanagement, disaster
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