GEO Wednesday: The Lusi eruption
Lecture by Adriano Mazzini, Centre for Earth Evolution and Dynamics (CEED), UiO
Lusi (Java, Indonesia) is the largest erupting sediment-hosted hydrothermal system on Earth.
The eruption, nicknamed Lusi (LUmpur - “mud” in Indonesia Bahasa; SIdoarjo - the local Regency where the eruption occurred) appeared in East Java the 29th of May 2006 together with other aligned venting sites. This diffuse pattern soon gave way to focused geysers and a relentless eruption of mud breccia, water, and gas. The mud quickly overtook an urban area near the city of Sidoarjo, permanently displacing 60,000 persons, while swallowing the main highway linking East Java to the rest of the Island. And the mud kept coming, emitting up to 180,000 m3/day with powerfully erupting plumes. Nothing could stop it. Today, nearly 12 years later, 10 m high embankments surround Lusi framing a region of ~7 km2.
Through the Lusi Lab project, multidisciplinary studies aimed at understanding the dynamics and mechanisms of Lusi employing wide-ranging and extensive methods such as geophysical, geochemical, remote sensing, clasts petrography and numerical modeling. Converging results from all these studies reveal that the Lusi system is and has been connected with the neighbouring volcanic complex even before its inception in 2006. Results provided substantial evidence supporting a hydrothermal scenario for the initiation of this system. The data reveal that the deep (>4km) migration of magma and hydrothermal fluids into the organic-rich sedimentary basin baked the organics present in the source rocks triggering methamorphic reactions and generating substantial overpressure at depth. The depicted scenario does not represent an anomaly, since identical modern and palaeo systems are observed in other sedimentary basins neighbouring volcanic structures.
Once a month in the relaxed atmosphere of the Science Library geoscientists at the University of Oslo will present their research and thereby introduce geosciences to a wide audience, from first year Bachelor students to curious colleagues at the university. It is possible to ask questions after the presentations.
The talks are in Norwegian or in English.
Waffles and coffee/tea will be served.
All are welcome!