Eruption Parameters Measured In-flight during the 2022 Icelandic Meradalir Eruption

The 2022 Icelandic eruption of Meradalir along the Reykjanes Peninsula, was captured via videography in exceptional detail over much of its 18-day duration. This eruption, like the 2021 Fagradalsfjall eruption, did not pose significant threat to human life or infrastructure. However, many lava-fountaining eruptions elsewhere of similar character (2018 Lower East Rift Zone, Hawaii & 2021 Cumbre Vieja, La Palma, Spain) have caused substantial destruction. Understanding eruption dynamics at these volcanoes is critical for fine-tuning of hazard and risk assessment. With the increasing use of high-speed/resolution cameras in field settings, we are able to quantify in-flight parameters such as particle size and particle exit velocities, rather than having to solely rely on deposit characteristics from samples collected once an eruption has ceased. This is an important development because ground samples can be rapidly buried or reworked and are subject to additional fragmentation during transport and when hitting the ground. The abundance of quantitative information we can obtain from this, coupled with qualitative observations, has allowed us to deepen our understanding of processes of weak explosive eruptions.