On October 12, 2009, NASA's Terra spacecraft observed a prominent plume of ash extending westward from the Soufriere Hills volcano on the Caribbean island of Montserrat. This significant event was captured by the Moderate Resolution Imaging Spectroradiometer (MODIS) instrument, providing a clear natural-color satellite image of the ongoing volcanic activity.
A Glimpse of Volcanic Activity
The observation on October 12, 2009, was particularly notable as it occurred approximately one week after eruptive activity at Soufriere Hills had resumed on October 5th. Volcanic ash plumes are a critical focus for monitoring by agencies like NASA, as they pose substantial risks to aviation and can have broader atmospheric and climatic impacts.
The Soufriere Hills Eruption
The Soufriere Hills volcano is a stratovolcano that has been continuously active since 1995, profoundly impacting the island of Montserrat, including the destruction of its capital, Plymouth. The eruption activity on October 5, 2009, marked a renewed phase of unrest, leading to the formation of the westward-drifting ash plume that NASA's instruments detected.
NASA's Eye in the Sky: Terra and MODIS
The detection of the ash plume was made possible by advanced instruments aboard NASA's Earth-observing satellites.
- Terra Spacecraft: Launched in 1999, NASA's Terra satellite is a flagship mission in the Earth Observing System (EOS). It collects data on Earth's atmosphere, land, and oceans, providing crucial insights into climate change and natural hazards.
- Moderate Resolution Imaging Spectroradiometer (MODIS): The MODIS instrument, onboard both the Terra and Aqua satellites, is vital for monitoring large-scale global dynamics, including volcanic eruptions. It captures images across a wide range of spectral bands, allowing scientists to identify and track phenomena like ash plumes, wildfires, and changes in land cover.
Key Observation Details
The following table summarizes the specifics of NASA's observation on October 12, 2009:
| Observation Aspect | Detail |
|---|---|
| Date | October 12, 2009 |
| Observed Event | Plume of ash extending westward |
| Source | Soufriere Hills volcano, Montserrat |
| NASA Spacecraft | Terra |
| Instrument | Moderate Resolution Imaging Spectroradiometer (MODIS) |
| Context | Observed one week after eruptive activity resumed on October 5th |
Importance of Monitoring Volcanic Ash
Monitoring volcanic ash plumes is essential for several reasons:
- Aviation Safety: Ash particles can cause severe damage to aircraft engines, leading to engine failure. Real-time satellite imagery helps reroute flights to avoid hazardous areas.
- Climate Studies: Large-scale volcanic eruptions can inject significant amounts of ash and gases into the stratosphere, influencing global climate patterns and atmospheric chemistry for months or even years.
- Hazard Mitigation: Tracking ash plumes assists local authorities in issuing warnings and implementing evacuation plans for affected populations.
The imagery from NASA's Terra satellite on October 12, 2009, provided invaluable data for understanding the dynamics of the Soufriere Hills eruption and its atmospheric spread.
