Gunung Colo (Colo volcano) with elevation 507m asl, located form the isolated small island of Una-Una in the middle of the Gulf of Tomini in central Sulawesi, 45 km from Wakai distric or 75km from Anpana City is a part of Togean Islands.

Mount Colo have activity in the crater, Local diver reported they heard about explosive eruption from underwater last 3 years and before inside crater is clean water and already more than 3 years is salt water from the sea

Only three eruptions have been recorded in historical time.
The last eruption, in July 1983, produced pyroclastic flows and explosive eruption with alot of Produce Vulcanic ash and sand Material also alot of Lapili over most of the island shortly after all residents had been evacuated. and Vulcanic ash until more than 400 km to west at Palu City and Also to east until Luwuk Regency.
when this volcano eruption, Local people said: Also made Small Tsunami about 1 m around Togean Islands

when I visited on June 30.2012 I walking following path of Lava Flow River (Lahar River) take about 2 hours until to The Crater where in 1983 this Eruption

Gunung Colo - Presure of Sea Water and made salt and Sea Water river with elevation 270m asl

Eruption History
1898 May 03 The eruption had a VEI of 3, qualifying as ‘severe’. It involved Central vent eruption, Crater lake eruption, Explosive eruption, Lahars

1938 – Unknown, The eruption had a VEI of 1, qualifying as ‘severe’. It involved Central vent eruption, Colo Crater with Phreatic Eruption after +/- 10 years after 1898

1983 July 18 This eruption was more violent and had a VEI of 4. It involved: Central vent eruption Explosive eruption ,Pyroclastic flow(s) , Phreatic explosion , Strombolian Eruption, and Tsunami, and evacuation was done, and there was damage to property. Thankfully, nobody was killed

Salt Crystal from steaming sea water inside of Colo Crater

Sulfur Vent on Colo Crater, temperature more than 150c

This Water fall made by Mt Colo Volcanic Activity, this very salty and also very hot temperature more than 120 c also made river from sea water

Pulau Una - Una (Mount Colo) central sulawesi, Indonesia

othes photo see here [picasaView album=”ColoVolcano” instantView=”yes”]

some source information from : Global Vulcanism Program – Colo Volcano