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Large igneous provinces (LIPs) represent some of the greatest volcanic events in Earth history with significant impacts on ecosystems, including mass extinctions. However, some fundamental questions related to the eruption rate, eruption style, and vent locations for LIP lava flows remain unanswered. In this review, we use the Cretaceous–Paleogene Deccan Traps as an archetype to address these questions because they are one of the best-preserved large continental flood basalt provinces. We describe the volcanological features of the Deccan flows and the potential temporal and regional variations as well as the spatial characteristics of potential feeder dikes. Along with estimates of mean long-term eruption rates for individual Deccan lavas from paleomagnetism and Hg proxy records of ∼50–250 km3/year (erupting for tens to hundreds of years), the Deccan volcanic characteristics suggest a unified conceptual model for eruption of voluminous (>1,000 km3) LIP lavas with large spatial extent (>40,000 km2). We conclude by highlighting a few key open questions and challenges that can help improve our understanding of how the Deccan flows, as well as LIP flows in general, erupted and the mechanisms by which the lavas may have flowed over distances up to 1,000 km. The Deccan Traps are an archetype for addressing fundamental volcanological questions related to eruption rate, eruption style, and vent locations for large igneous province lava flows. Deccan subprovinces likely evolved as separate volcanic systems; thus, long-distance/interprovince flow correlations must be carefully assessed. The earliest eruptions came through the Narmada-Tapi rift zone followed by the establishment of a separate magmatic plumbing system by mantle plume–associated magmas. Typical Deccan eruption rates were ∼50–250 km3/year of lava. Individual eruptions lasted for a few hundred to 1,000 years and were separated by hiatuses of 3,000–6,000 years. The conspicuous absence of dikes in the Central Deccan region strongly implies long-distance surface transport of lavas in the form of flows hundreds of kilometers long. [ABSTRACT FROM AUTHOR]

The ongoing effusive phase of the eruption of Sinabung Volcano (Sumatra, Indonesia) began in late December 2013, and has produced a 2.9 km long andesitic lava flow with two active secondary summit lobes, frequent pyroclastic density currents (PDCs) (with ≤5 km runout distance), and associated plumes up to 5 km in height. Large intermediate to silicic composition lava flows of the type documented here are common at volcanoes around the world, but they are infrequently observed while active. This eruption provides a special opportunity to observe and study the mechanisms of emplacement and growth of an active andesitic lava flow. We use visible and thermal satellite images to document the flow and describe the dominant processes driving emplacement of the lava over the course of the eruption. Effusion and flow advance rates were at their highest in January–March 2014. A decrease in flow advance rate in late March 2014 from 20 to 70 m d−1 to <5 m d−1 was the result of a decrease in effusion rate from ~9 m3 s−1 to ~3 m3 s−1. Initial flow emplacement was most likely controlled by the yield strength of the flow crust, which we estimate to have increased in thickness from 1 to 4 m during January–June 2014, calculated from average flow surface temperatures that decreased from ~60 °C to <30 °C during this period. Further decrease in flow advance rate in June 2014 to ~1 m d−1 suggests that the flow's interior had cooled, and that propagation was limited by the yield strength of the flow's interior (core). Inflation of the flow during this period of core-controlled slow advance eventually caused lava to overtop ridges bounding the flow near the summit, and created significant gravitational instabilities. These instabilities led to collapse of the upper portions of the lava flow and generated PDCs, followed by breakout of new flow lobes from the collapse scars in October 2014 and June 2015. Effusion continues as of June 2017 and presents a significant hazard for collapse and generation of PDCs. This ongoing activity appears to represent a typical eruption of Sinabung, with flow length and area similar to numerous older flows observed around the volcano. • The emplacement mechanisms of the lava flow at Sinabung during 2014 are described. • Effusion (~9 m3 s−1) and flow advance (20–70 m d−1) rate were highest in Jan–Mar 2014. • Flow advance rate decreased twice: in March (~4 m d−1) and June (~1 m d−1) of 2014. • A decrease in effusion rate (to ~3 m3 s−1) caused the March flow advance decrease. • A transition from crust- to core-controlled flow advance caused the June decrease. [ABSTRACT FROM AUTHOR]

An effusive eruption at Sinabung Volcano in Indonesia began in December 2013. We use structure-from-motion (SfM) photogrammetric techniques to create digital elevation models (DEMs) of the active lava flow. We build DEMs from photographs taken during two separate time periods and from two separate low-cost handheld cameras and compare them with a pre-eruption DEM to assess the quality and accuracy of photogrammetric DEMs created using different cameras, calculate flow volume and long-term average effusion rate, and document changes in flow morphology. On September 22nd, 2014, the lava flow was 2.9 km long and had a volume of 1.03 ± 0.14 × 108 m3, leading to an estimated time-averaged discharge rate of 4.8 ± 0.6 m3 s−1. Differencing the photogrammetric DEMs shows that during the two-week field campaign, topographic changes of the flow occurred in zones along the flow front and on the upper flank, a finding supported by relatively high temperatures in corresponding thermal images. The deformation can be explained by active advance at the flow front and development of instabilities and collapse on the upper flanks. Large pyroclastic density currents associated with gravitational collapse of upper-flank instabilities in October 2014 and June 2015 were caused by lava growing over ridges that had initially confined the flow to a pre-existing channel. This work demonstrates the ability of SfM photogrammetry to measure or identify the lava flow volume, time-averaged discharge rate, flow emplacement rate and style, as well as the development of gravitational instabilities. Our results show the potential of SfM photogrammetry as a cost- and time-effective method of repeatedly measuring active volcanic features and monitoring hazards at Sinabung and during similar eruptions. • We apply photogrammetry to create multiple DEMs of the recent Sinabung lava flow. • On Sept 22, 2014, the volume of the lava flow was 1.03 ± 0.14 × 108 m3 (0.1 km3). • Between Jan 10 and Sept 22, 2014, the average effusion rate was 4.8 ± 0.6 m3 s−1. • Flow inflation caused it to overtop confining ridges, leading to instabilities. • In Sept 2014, flow front advance was 3–11 m d−1, isolated to a few breakout lobes. [ABSTRACT FROM AUTHOR]