Observing Iceland's Eyjafjallajökull 2010 eruptions with the autonomous NASA Volcano Sensor Web

Abstract

Land Imager (ALI) on NASA's Earth Observing 1 (EO-1) spacecraft obtained an unprecedented sequence of 50 observation pairs of the eruptions at Fimmvörðuháls and Eyjafjallajökull, Iceland. This high acquisition rate was possible only through the use of data flow streamlined by using the autonomously operating NASA Volcano Sensor Web (VSW). The VSW incorporates notifications of volcanic activity from multiple sources to retask EO-1 and process Hyperion data to extract eruption parameters from high spatial and spectral resolution visible and short-wavelength infrared data. Physical changes in eruption style and magnitude were charted as the eruptions ran their course. Rapid data downlink and automatic data-processing algorithms generated a variety of products which are compared with estimates from ground-based observations and post-eruption in situ measurements. Estimates of effusion rate from heat loss measurements underestimate actual effusion rate (while still following broad eruption rate trends) but are closer to in situ estimates for effusive eruptions (Fimmvörðuháls) than explosive, ash-rich eruptions (Eyjafjallajökull). During the later stages of the 2010 eruption, VSW-generated products were rapidly delivered to end-users in Iceland to aid in the assessment of risk and hazard. The success of the VSW led to Icelandic Meteorological Office (IMO) in situ sensors being incorporated into the VSW, and in May 2011 an IMO seismic alert autonomously triggered EO-1 observations of a new eruption at Grímsvötn volcano. Finally, the VSW demonstrates an autonomy-driven, multi-asset, spacecraft retasking and data processing system that maximizes science return, a desirable capability for future NASA missions.

The NASA Volcano Sensor Web, advanced autonomy and the remote sensing of volcanic eruptions: a review

“…These products are a mixture of: higher-level radiance data products, such as the 'geo-located' (L1G) Hyperion and ALI products; image products, such as visible-wavelength images of the target, created from Hyperion and ALI data; maps showing the location of 'active' pixels detected by the THERMAL_CLASSIFIER algorithm; and quantification of the thermal emission from the ongoing volcanic eruption. Examples of all of the Hyperion products are given in Davies et al (2008aDavies et al ( , 2013.…”

“…Observers on the ground watched as lava erupted from vents along a SW-NE-trending fissure and flowed northeastwards into a gorge named Hrunagil (e.g. Davies et al 2013). On 24 March 2010, a lava channel approximately 30 m wide could be seen in ALI PAN data (Fig.…”

“…The EO-1 observing campaign and the data collected are described by Davies et al (2013), from which the following description is taken. This eruption took place in a very different logistical setting to that of Nyamulagira.…”

An Overview of Infrared Remote Sensing of Volcanic Activity

“…The principle of differencing MIR and TIR signals was also utilised in a later, AATSR-bespoke volcano monitoring system: "Volcanoes Monitoring by Infra-Red", or VoMIR [99]. Arguably the most sophisticated automated system of the period was the "Autonomous Sciencecraft Experiment System" (later named the "Volcano Sensor Web") developed for the sensors of the EO-1 spacecraft [100,101]. This system functioned by processing Hyperion SWIR data; if a potential hot surface was identified, then a trigger was generated to re-point the Hyperion sensor appropriately.…”

“…The system could also be triggered by other sources, such as MODIS, or on-the-ground observations, which re-tasked the satellite to make follow-up observations within two days of notification [100,102]. The effectiveness of this system was demonstrated during the 2010 Eyjafjallajökull eruption, when 50 such observations were made of the erupting volcano over a period of 74 days, ultimately providing data to stakeholders in Iceland to assist in risk and hazard assessments [101].…”