The Grímsvötn Volcano, located beneath Iceland's Vatnajökull glacier, erupted in 2004. The eruption resulted in the formation of ash plumes that reached high into the atmosphere, leading to concerns about air travel disruptions and environmental effects.

• Image 1: Product: ENVISAT.ASA.WSM_1P, Satellite: Envisat, Instrument: Advanced Synthetic Aperture Radar (ASAR), Instrument Features: Image Mode Precision (150 metre resolution), Acqusition Date: 16 November 2004, Orbit: 14516 / 14191, Orbit Direction: Descending