LUSI-LAB1

http://folk.uio.no/adrianom/LUSI%20LAB.html

The LUSI LAB Project

The spectacular Lusi eruption started in northeast Java the 29 of May 2006 following to a 6.3 M earthquake striking the island. Initially, several gas and mud eruption sites suddenly appeared along a reactivated fault system and within weeks several villages were submerged by boiling mud. The most prominent eruption site was named Lusi. To date Lusi is still active and erupting gas, water, mud and clasts.

Recent gas analyses highlighted that the root of the feeder channel are as deep as 4.5 km. The results are consistent with deep sited magmatic intrusions and hydrothermal fluids, from the neighbouring Arjuno volcanic complex, responsible for the enhanced heat that altered source rocks and/or gas reservoirs.

Despite the work done, still many unanswered questions remain. What lies beneath Lusi? If Lusi is not a mud volcano, how large is the connected hydrothermal system? How do the frequent seismic activity and the neighbouring Arjuno Welirang volcanic complex affect the pulsating Lusi behaviour? What are the mechanisms triggering the eruption? How long will the eruption last? Are more eruptions like this one likely to occur?

I recently won the 2012 ERC startup grant presenting a project (LUSI LAB) to continue my studies on the Lusi eruption. LUSI LAB is an ambitious project that aims to answer these questions and to perform a multidisciplinary study using Lusi as a unique natural laboratory. Due to its relatively easy accessibility, the geological setting, and the vast scale, the Lusi eruption represents an unprecedented opportunity to study and learn from an ongoing active eruptive system. Detailed investigations on erupting features are difficult and have never been carried out before. The results will be crucial for understanding focused fluid flow systems in other sedimentary basins world-wide, and to unravel issues related to geohazards and palaeoclimate aspects.

LUSI LAB will focus on five main aspects in order to complete a comprehensive regional investigation: 1) monitoring on local micro-seismicity related to regional seismicity; 2) monitoring and sampling of the neighbouring volcanic arc; 3) sampling and monitoring of the active Lusi eruption site; 4) monitoring of the fault system originating from the volcanic arc, crossing Lusi and extending to the NE of java island; 5) numerical modelling of Lusi activity.

In order to achieve the aims, the project will use the deployment of multisensory sampling devices within the active feeder channel coupled with a remote-controlled raft and flying device to access and sample the crater and the erupted gases. UV-gas camera imaging will be used to measure the rate and composition of the erupted gases. These data together with a new network of GPS and seismometers, will allow the evaluation of the impact that seismicity, local faulting and the neighbouring Arjuno-Welirang volcanic complex have on the long-lasting Lusi activity. The acquired information will provide robust constraints to model the pulsating Lusi behaviour and will be used as initial step to estimate the longevity of the eruption.