Earthquake cracks Sinila volcanic crater in Dieng Plateau, releases poisonous H2S gas and kills 149 villagers in Indonesian province of Central Java.

The Dieng Plateau is a marshy plateau that forms the floor of a caldera complex on the Dieng Volcanic Complex in Wonosobo and Banjarnegara, Central Java, Indonesia. Referred to as "Dieng" by Indonesians, it sits at 2,000 metres (6,600 ft) above sea level, far from major population centres. The name "Dieng" comes from Dihyang which means "place of the ancestors or gods".Part of General Sudirman's guerrilla campaign during the Indonesian War of Independence took place in the area.

An earthquake (also known as a quake, tremor or temblor) is the shaking of the surface of the Earth resulting from a sudden release of energy in the Earth's lithosphere that creates seismic waves. Earthquakes can range in size from those that are so weak that they cannot be felt to those violent enough to propel objects and people into the air, and wreak destruction across entire cities. The seismicity, or seismic activity, of an area is the frequency, type, and size of earthquakes experienced over a particular time period. The word tremor is also used for non-earthquake seismic rumbling.

At the Earth's surface, earthquakes manifest themselves by shaking and displacing or disrupting the ground. When the epicenter of a large earthquake is located offshore, the seabed may be displaced sufficiently to cause a tsunami. Earthquakes can also trigger landslides and, occasionally, volcanic activity.

In its most general sense, the word earthquake is used to describe any seismic event—whether natural or caused by humans—that generates seismic waves. Earthquakes are caused mostly by rupture of geological faults but also by other events such as volcanic activity, landslides, mine blasts, and nuclear tests. An earthquake's point of initial rupture is called its hypocenter or focus. The epicenter is the point at ground level directly above the hypocenter.