Radiant flux from Earth's subaerially erupting volcanoes

Abstract

During the past decade an average of 60 volcanoes erupted each year, around 20 of which were erupting on any given day. Some of these, such as Erta Ale in Ethiopia, are persistently active, whereas others, such as Bezymianny in Russia, erupt more sporadically. Satellite remote sensing offers a convenient way to monitor changes in the thermal budgets of these volcanoes from space. Using data acquired by the National Aeronautics and Space Administration (NASA) Moderate Resolution Imaging Spectroradiometer (MODIS) sensor, we show how the amount of heat radiated into the Earth's atmosphere by 65 active volcanoes has varied between 26 February 2000 and 31 December 2006. We find that the radiant volcanic heat flux into the atmosphere occurs at a relatively steady‐state baseline level, superimposed on which are large thermal emission ‘spikes’. These anomalous emission events are associated with the emplacement of basaltic ‘a’a lava flows at volcanoes such as Mount Etna, Italy, and Nyamuragira, in the Democratic Republic of Congo. We also demonstrate how these data can be used to estimate lava effusion rates during effusive eruptions, and magma flux rates at persistently active volcanoes that host active lava lakes.