October 2010 events in Indonesia

Puteri Indonesia 2010, the 15th Annual Puteri Indonesia beauty pageant, was held in Jakarta Convention Center, Jakarta, Indonesia on October 8, 2010. Thirty eight contestants from all 33 provinces of Indonesia competed for the title of Puteri Indonesia, one of the most prominent beauty pageant titles in the country. Qory Sandioriva, Puteri Indonesia 2009 from Aceh crowned her successor Nadine Alexandra Dewi Ames of Jakarta SCR 4 at Assembly Hall, Jakarta Convention Center, Jakarta. Ames is going to represent Indonesia at the Miss Universe 2011 in São Paulo, Brazil, while the first and second runners-up will represent the nation at the Miss International 2011 and the Miss Asia Pacific World 2011 respectively.

In late October 2010, Mount Merapi in Central Java, Indonesia began an increasingly violent series of eruptions that continued into November. Seismic activity around the volcano increased from mid-September onwards, culminating in repeated outbursts of lava and ashes. Large eruption columns formed, causing numerous pyroclastic flows down the heavily populated slopes of the volcano. Merapi's eruption was said by authorities to be the largest since the 1870s.

The 2010 Mentawai earthquake occurred with a moment magnitude of 7.8 on 25 October off the western coast of Sumatra at 21:42 local time (14:42 UTC). The earthquake occurred on the same fault that produced the 2004 Indian Ocean earthquake. It was widely felt across the provinces of Bengkulu and West Sumatra and resulted in a substantial localized tsunami that struck the Mentawai Islands.

The 2010 West Papua floods occurred on 6 October 2010 in the eastern Indonesian province of West Papua. The floods, which have centered on the town of Wasior in West Papua, resulted from heavy rains resulted in a river overflowing its banks, causing landslides.

The Petarukan train collision occurred on 2 October 2010, at Petarukan, in Pemalang Regency of Central Java, Indonesia, when two intercity trains collided with each other. Thirty-six people died as a result of the accident, and 50 people were reported injured.