More than ten years of Lusi: A review of facts, coincidences, and past and future studies

Abstract

The Lusi mud eruption in East Java, Indonesia, has continued unabated for more than ten years with no end in sight. This review summarizes what has been learned about this intriguing system, from its inception to the current (2017) well-established metastable geysering system that continuously erupts mud breccia, gas, steam, and water. We discuss the initiation of Lusi, highlighting discrepancies and evidence through the published data, to build a comprehensive database that emphasizes how the results converge towards a natural scenario of this system. We argue that attempts to understand, constrain, or predict the behaviour of this system that rely on a drilling trigger can not explain subsequent observations. On the other hand, we show that a well-constrained conceptual model recognizing Lusi as a volcanicallylinked hydrothermal system, has provided important insights for the documented observations over the last ten years. The response of Lusi to the Yogykarta earthquake falls directly within the range of earthquake triggering phenomena (globally) of similar hydrothermal/geothermal systems, suggesting a natural trigger as the more likely culprit for the Lusi phenomenon. We also

The Plumbing System Feeding the Lusi Eruption Revealed by Ambient Noise Tomography

“…Since 29 May 2006, the densely populated Sidoarjo district, located in the NE of the Java sedimentary basin, has witnessed the extensive eruption of boiling mud, clasts, and fluids (Miller & Mazzini, ; Van Noorden, ). The large scale of the mud eruption, nicknamed Lusi, significantly impacted this area with nearly 60,000 people forced to abandon their villages due to the hot erupting mud covering a region of ~7 km 2 (Richards, ).…”

An alternative review of facts, coincidences and past and future studies of the Lusi eruption

“…However, over this entire 5 hour period, the 487 drill pipe pressure (measured at the surface) is 500-600 psi, and indicates that the 488 wellbore was exposed to approximately the equivalent pressure observed during 489 the initial kick event, which was sufficient to exceed the fracture pressure as 490 evidenced by the daily drilling report's stated losses during the kick. (Miller and Mazzini, 2017). However approximately half foot bubbles occasionally came to the surface" (Figure 5).…”

“…To interpret observations made during this eruption, we contend 46 that it is essential to understand the processes that initiated the eruption. In the 47 timely review by Miller and Mazzini (2017), the eruption is attributed to an 48 earthquake and the authors argue that the adjacent drilling operations at the 49 Banjarpanji-1 (BJP-1) well played no role. 50 51…”

“…84 These two issues are essentially the key to distinguishing between the earthquake-85 and drilling-trigger arguments, as summarized in Figure 1. Here we assess key 86 claims in the review by Miller and Mazzini (2017) using published data from daily 87 reports and drilling logs and we revisit the analysis of how earthquakes trigger 88 eruptions. We argue that the evidence strongly supports the drilling-trigger model, 89…”

“…Miller and Mazzini (2017) claim there is no pressure to drive fracture propagation. This is not correct.…”