The Smithsonian / GVP monthly Bulletin of the Global Volcanism Network for Jan 2013 confirms that Heard Island volcano is in eruption. A series of satellite images compared side by side show that the volcano started to produce lava (over-)flows from the summit crater of the Mawson Peak on the SE flank since December past year.

A significant heat source continues to show up on MODIS satellite data. A recent (9 March) EO1-Hyperion (NASA) satellite picture shows what could be a lava lake in the summit crater of Mawson Peak. ...plus

A significant hot spot continues to be detected at the summit crater of Heard volcano. A recent Terra / Modis satellite image of parts of the volcano (which usually is completely hidden under clouds) shows a dark area immediately to the west of Mawson Peak. This could correspond to a fresh lava flow.

MODIS hot spots have remained visible at the summit of Heard island, suggesting ongoing activity at this very remote volcano.

Several hot spots are visible in and near the summit crater on MODIS satellite data, suggesting that activity (lava dome growth?, explosive activity?) is continuing.

A MODIS hot spot was visible yesterday at the summit of the volcano, despite the usual dense cloud cover. This indicates that some sort of activity likely continues.

A new eruption seems to have started. An ash plume rising to 20,000 ft (6 km) altitude and drifting 120 nautical miles to the SW was reported last night by VAAC Darwin. The aviation color code was raised to RED.

A thermal hot spot remains visible at the summit crater on MODIS satellite data, suggesting that some activity continues there.