As part of the VISOR effort, we aim to map the recent (1980-present) lava flows from Nyamuragira, in order to quantify the magmatic output of this highly productive volcano and compare it with SO₂ emissions measured by TOMS and OMI. To do this, we have collated an archive of satellite data from the Landsat Multispectral Scanner (MSS), Thematic Mapper (TM), and Enhanced Thematic Mapper (ETM+) and the Advanced Spaceborne Thermal Emission and Reflection radiometer (ASTER) on NASA's Terra satellite . Some snapshots of this archive are available below.

• Location map of the Virunga volcanoes in eastern DR Congo.

• 1975 (March 12): Early MSS image of the Virunga, prior to Nyamuragira's very active phase beginning in 1980. Note the plume from Nyiragongo, emitted by the lava lake that was active in the crater at the time.

• 1984 (December 4): Partly cloudy MSS scene, showing lava flows erupted from Nyamuragira in 1976, 1980, 1981 and 1984. Degassing from Nyiragongo is no longer evident.

• 1986 (July 19): TM image collected whilst the July 1986 eruption of Nyamuragira was in progress from a vent on its southern flank.

• 1987 (August 7): Nearly cloud-free TM scene, showing the 1986 lava flow and earlier flows. The chilled lava lake surface in the summit crater of Nyiragongo is also visible.

• 1989 (August 4): TM image showing the products of the 1987 and 1989 eruptions of Nyamuragira. Fresh ashfall on vegetation (or possibly the effects of acid gas emissions) can be clearly seen at Nyamuragira's summit and near the NE flank vent.

• 1995
  • January 17: TM scene showing the 1991-92 lava flows on the far northern flank of Nyamuragira, and the 1994 lava flow on the west flank. A hotspot in Nyiragongo's summit crater, and weak gas emissions, are due to a short-lived reactivation of the lava lake in 1994-95.
  • February 2: TM image a few weeks later with a clearer view of the 1994 lava flow, and continued lava lake activity at Nyiragongo.

• 1999 (December 6): Partly cloudy ETM+ image showing the 1996 and 1998 lava flows from Nyamuragira (both on the NW flanks).

• 2000
  • June 15: Partly cloudy ETM+ scene with a partial view of the January 2000 lava flow on Nyamuragira's SE flank.
  • September 3: This ETM+ image is also partly cloud-covered, but more of the 2000 lava flow is visible.

• 2001 (December 11): Very clear ETM+ image showing the large flow field emplaced during the February 2001 eruption of Nyamuragira (NW and SE flanks). Note the fumarolic activity in the summit crater of Nyiragongo, just one month before its 17 January 2002 eruption.

• 2003 (January 31): Nearly cloud-free ETM+ scene showing lava flows from Nyamuragira's 2002 eruption on its northern flank. Nyiragongo's active lava lake and gas plume are visible following reactivation in mid-2002. The lava flows disgorged by Nyiragongo during its January 2002 eruption, some of which entered the city of Goma and Lake Kivu, are also visible on its southern flanks.

• 2005 (February 21): Very clear ETM+ image showing lava flows emitted on Nyamuragira's NW flanks during its May 2004 eruption, and continued gas emissions from Nyiragongo's lava lake.

• 2007 (June 19): ASTER visible image showing lava flows emitted on Nyamuragira's SE flanks during its most recent eruption (to date) in November 2006, and continued gas emissions from Nyiragongo's lava lake.