Determination of the Instantaneous Lava Effusion Rate of Hawaiian Style Volcanic Eruptions by Continuous Very Low Frequency Electromagnetic Monitoring of Active Lava Tubes

Measurement of lava effusion rates helps constrain geophysical models for magma dynamics, conduit geometry, and deep volcano processes and is a key objective for monitoring basaltic eruptions such as those of Kilauea Volcano, Hawaii. A variety of methods are currently used to estimate average effusion rates and while these strategies produce results that are in basic agreement, significant discrepancies are not uncommon. Furthermore, events with short temporal duration cannot be studied, which seriously limits our understanding of most basaltic eruptions and corresponding hazards. A significant percentage of basaltic lava frequently flows through a single, long-lived lava tube, such as occurs at Kilauea's East Rift Zone (ERZ), for example. A new instrument is described for continuously monitoring the cross-sectional area of lava in a master lava tube and estimating the instantaneous flux of lava flowing from a volcano. The design utilizes a stationary receiver which allows for the continuous monitoring of the lava effusion rate while minimizing exposure of researchers to the risk associated with monitoring active volcanoes up close. This represents the first long-term, continuous monitoring capability of instantaneous effusion rate of an ongoing volcanic eruption.