Lava Flows (Lava Domes)
Primary reference(s)
Calder, E.S., Y. Lavallee, J.E. Kendrick et al., 2015. Lava dome eruptions. In: Sigurdsson, H., B. Houghton, H. Rymer et al. (eds.), The Encyclopedia of Volcanoes, 2nd Edn. pp. 343-362. Academic Press.
Kilburn, C.R.J., 2015. Lava flow hazards and modelling. In: Sigurdsson, H., B. Houghton, H. Rymer et al. (eds.), The Encyclopedia of Volcanoes, 2nd Edn. pp. 957-969. Academic Press.
Additional scientific description
A lava flow may comprise smaller bodies of lava known as ‘lava flow units’, or ‘lava flow lobes’; a lava flow comprising multiple lava flow units is known as a ‘lava flow field’. Pillow lavas are lava flows formed under water. Lava domes may be described as a type, such as Peléan domes. Lava coulées are a hybrid between lava domes and flows, they are short, thick, viscous lava flows that typically form on a slope.
Most volcanoes erupt lava flows and/or domes during their lifetimes (Kilburn, 2015). Effusions of lava commonly continue from days to months, but occasionally for decades. Lava flows damage and destroy land and property but usually (not always) advance slowly enough for populations to escape. Understanding where future lava may be erupted from (the vent or vents), how far a lava flow may advance, the velocity of the flow front and the area that may be covered are critical for hazard assessments (Kilburn, 2015). Viscous lava flows and lava domes can generally be avoided but they may collapse to generate very hazardous pyroclastic density currents (Calder et al., 2015; Carr et al., 2019). The main factors controlling how a lava flow or dome develops are the lava’s rheological properties, effusion (or extrusion) rate and underlying topography.
The rheological properties of lava are influenced by chemical composition. Fluid and mobile lava flows tend to be low in silica (e.g., mafic compositions such as basalt); lava with moderate silica content is more viscous and tends to form short blocky lava flows or lava domes (e.g., intermediate compositions such as andesite); the most silica-rich lava is most likely to form a lava dome (e.g., felsic compositions such as rhyolite). The Cordón Caulle eruption in 2011–2012, shows that rhyolitic and basaltic compound lava flows may have much in common in terms of physical processes, despite very different rheologies (Tuffen et al., 2013).
Parts of lava flows and lava domes can remain molten after an eruption has ended (e.g., Calder et al., 2015; Pederson et al., 2017) and this may lengthen the timescale of hazardous lava flow advance or potential for lava dome collapse.
Lava flow characteristics: Surface morphology of subaerial basaltic lava flows may be described as pāhoehoe (Hawaiian meaning ‘smooth, unbroken’) or a‘ā (Hawaiian meaning ‘stony, rough lava’), whereas intermediate or silica-rich lava is more likely to have a blocky surface morphology (Harris et al., 2017). Basaltic pāhoehoe flows commonly have the highest eruption temperatures of 1100 to 1200°C, whereas rhyolitic lavas are typically 650–750°C (Kilburn, 2015). The unique ‘natrocarbonatite’ lava flows at Ol Doinyo Lengai volcano in Tanzania are dominated by carbonates rather than silicates and form very fluid, relatively low temperature lavas (500–600°C) (Pinkerton et al., 1995).
At the start of an eruption, basaltic lavas may advance at several kilometres per hour, but slow to walking pace or less within a few hours (Kilburn, 2015). On steep slopes some lavas may reach higher velocities of tens of kilometres per hour. Exceptionally, in 1977, lava flowed down the slopes of Nyiragongo with a maximum velocity of up to 100 km/h (Balagizi et al., 2018). Viscous lavas may typically advance at rates of 0.1 km/day or less.
Typically, basaltic lava flows may reach lengths of 1–10 km, but occasionally more than 30 km (e.g., the Laki eruption in Iceland between 1783 and 1785; Thordarsson and Self, 1993) and some pāhoehoe flows have reached 50 km (Kilburn, 2015). Basaltic lava flows may be 3–20 m thick and typical volumes of historical lava flows on land are between 0.01 and 0.1 km3 (flow fields can exceptionally exceed 10 km3). Intermediate and silicic lavas are usually shorter in length, typically up to 5 km but some are up to 15 km. They may be 20–300 m thick and volumes are typically 0.01 and 0.1 km3 but can be up to 10–20 km3 (Kilburn, 2015).
Models: The simplest empirical models are volcano-specific and link effusion rate to runout length but more complex models account for cooling-induced changes in rheology as a lava flows over topography (e.g., Harris et al., 2013). New methodologies are constantly developing (e.g., Gallant et al., 2018) and generally have a two-step process: statistical analysis to establish known vent distributions and identify most likely future vent sites, followed by an estimation of the areas of inundation by lavas flowing from those vents (e.g., Connor et al., 2012). Outputs are highly sensitive to topography, as well as estimated volume of lava and flow dynamics (e.g., Dietterich et al., 2017). High resolution Digital Elevation Models are necessary (e.g., Turner et al., 2017) but in urban and man-made environments Digital Surface Models may be more appropriate (e.g., Tsang et al., 2020).
Probabilistic hazard assessments for lava flows can anticipate inundation so are useful for long-term planning (e.g., hazard maps) and short-term forecasting (e.g., Vicari et al., 2011). However, more study is required at many volcanoes that lack important metrics such as recurrence interval, or volume of previous lava flows (e.g., Wantim et al., 2018). Lava flow and dome collapses: Viscous lava flows and domes may exhibit various collapse styles from persistent rock falls to partial or total collapse of a lava dome.
Lava flow or dome collapse may generate potentially deadly pyroclastic density currents and associated hazards such as tephra and gas emissions (Calder et al., 2015; Harnett et al., 2019). Lava dome collapse hazard assessments are rarely in place but are needed (Harnett et al., 2019).
Metrics and numeric limits
Not identified.
Key relevant UN convention / multilateral treaty
Sendai Framework for Disaster Risk Reduction 2015–2030 (UNDRR, 2015).
Examples of drivers, outcomes and risk management
Primary hazards. Lava flows may cause damage to buildings, infrastructure, communications, agriculture and environment by inundation, burial, transport, fire and explosion (e.g., Jenkins et al., 2017). Damage may not be complete but partial burial or inundation by lava generally makes buildings, infrastructure and land unusable (Jenkins et al., 2017). Buried infrastructure may also be destroyed due to thermal impacts (Tsang et al., 2020). Injuries may occur if individuals walk on a lava carapace with molten lava below. Health impacts may include burns, gas and aerosol inhalation. Viscous lava flows and domes in particular may be associated with episodes of explosive volcanic activity and additional primary volcanic hazards such as pyroclastic density currents, tephra and volcanic gases which in combination worsen the overall impact (Wantim et al., 2018).
Secondary hazards. Escape routes may be cut off, or the lavas may trigger explosions on meeting snow, ice and water, or flammable fluids. For example, in Goma in 2002, around 300,000 people self-evacuated and there were roughly 140 deaths, most caused by explosions at a petrol station that had been surrounded by lava (Balagizi et al., 2018). Lava flows may ignite forest or urban fires (e.g., Wantim et al., 2018). Volcanic gases and aerosols (air pollution) need to be considered, possibly over large areas (Barsotti et al., 2020). Evacuation to emergency accommodation may lead to permanent displacement, which if combined with loss of livelihoods and homes, may cause longer term mental and physical health impacts, and the long-term cascading effects can be more severe than immediate impacts (Wantim et al., 2018).
Between 1500 AD and 2017 there were 25 documented fatal incidents and 659 fatalities caused directly by lava flows, with fatalities occurring between 1 and 29 km of the volcanic source (median distance 11 km) (Brown et al., 2017). Fatalities and casualties occur when eruptions begin from vents close to towns and/or lavas are very fluid, on steep slopes and fast moving. For example, the 1977 eruption of Nyiragongo generated lava flows that killed about 70 people (Balagizi et al., 2018).
Viscous lava flows and lava domes do not directly cause fatalities and injuries, but their collapse may generate pyroclastic density currents which cause more fatalities than any other volcanic hazard (e.g., Calder et al., 2015; Brown et al., 2017).
If a volcanic area is well-monitored, the movement of magma in the subsurface may be detected days, weeks or even years before an eruption (e.g., Pederson et al., 2017; Pallister et al., 2019) enabling planning, preparation and emergency actions such as evacuation. Effective monitoring of the emplacement of lava flows and domes over time enables forecasting of inundation and the anticipation of hazardous events such as lava dome collapse (e.g., Vicari et al., 2011; Pallister et al., 2013, 2019; Pederson et al., 2017; Carr et al., 2019).
Probabilistic hazard maps can enable appropriate land-use planning policies before eruption avoiding development in areas with high probability of inundation (Tsang and Lindsay, 2020).
Attempts during ongoing eruptions to halt or divert flows (by erecting barriers, spraying lava with water, or breaking the margins of lava channels) have had mixed success (e.g., Barberi and Carapezza, 2004) nevertheless, in Hawaii, barriers have been constructed alongside new high value assets (Tsang and Lindsay, 2020). Evacuation remains the most effective strategy for protecting life and health from primary and secondary hazards (Tsang and Lindsay, 2020).
References
Balagizi, C.M., A. Kies, M.M. Kaseraka, D. Tedesco, M.M. Yalire and W.A. McCausland, 2018. Natural hazards in Goma and the surrounding villages, East African Rift System. Natural Hazards, 93:31-66.
Barberi, F. and M.L. Carapezza, 2004. The control of lava flows at Mt Etna. In: Bonacorso, A., S. Calvari, M. Coltelli and S. Falsaperla, Eds. Mt Etna Volcano Laboratory. American Geophysical Union Monograph, 143:357-369.
Barsotti, S. and 15 authors, 2020. Operational response and hazards assessment during the 2014–2015 volcanic crisis at Bárðarbunga volcano and associated eruption at Holuhraun, Iceland. Journal of Volcanology and Geothermal Research, 390:106753. Accessed 19 April 2021.
Brown, S., S. Jenkins, R.S.J. Sparks, H. Odbet and M.R. Auker, 2017. Volcanic fatalities database: analysis of volcanic threat with distance and victim classification. Journal of Applied Volcanology, 6:15. doi.org/10.1186/s13617-017-0067-4.
Calder, E.S., Y. Lavallee, J.E. Kendrick et al., 2015. Lava dome eruptions. In: Sigurdsson, H., et al. (Eds), The Encyclopedia of Volcanoes. 2nd Ed. pp. 343-362. Academic Press.
Carr, B.B., A.B. Clarke, L. Vanderkluysen and J.R. Arrowsmith, 2019. Mechanisms of lava flow emplacement during an effusive eruption of Sinabung Volcano (Sumatra, Indonesia). Journal of Volcanology and Geothermal Research, 382:137-148.
Connor, L.J., C.B. Connor, K. Meliksetian and I. Savov, 2012. Probabilistic approach to modeling lava flow inundation: a lava flow hazard assessment for a nuclear facility in Armenia. Journal of Applied Volcanology, 1:3. doi.org/10.1186/2191-5040-1-3.
Dietterich, H.R., E. Lev, J. Chen, J.A. Richardson and K.V. Cashman, 2017. Benchmarking computational fluid dynamics models of lava flow simulation for hazard assessment, forecasting and risk management. Journal of Applied Volcanology, 6:9. doi. org/10.1186/s13617-017-0061-x.
Gallant, E., J. Richardson, C. Connor, P. Wetmore and L. Connor, 2018. A new approach to probabilistic lava flow hazard assessments, applied to the Idaho National Laboratory, eastern Snake River Plain, Idaho, USA. Geology, 46:895-898.
Harnett, C.E., M.E.Thomas, E.S. Calder, S.K. Ebmeier, A. Telford, W. Murphy and J. Neuberg, 2019. Presentation and analysis of a worldwide database for lava dome collapse events: the Global Archive of Dome Instabilities (GLADIS). Bulletin of Volcanology, 81:16. doi.org/10.1007/s00445-019-1276-y.
Harris, A.J.L., 2013. Lava flows. In: Fagents, S.A., T.K.P. Gregg and R.M.C. Lopes (Eds), Modelling Volcanic Processes. Cambridge University Press, pp. 85-106.
Harris, A.J.L., S.K. Rowland, N. Villeneuve and T. Thordarson, 2017. Pahoehoe, aa and block lava: an illustrated history of the nomenclature, Bulletin of Volcanology, 79:7. doi.org/10.1007/s00445-016-1075-7.
Jenkins, S., S. Day, B.E. Faria and J. Fonesca, 2017. Damage from lava flows: insights from the 2014-2015 eruption of Fogo, Cape Verde. Journal of Applied Volcanology, 6:6. doi.org/10.1186/s13617-017-0057-6.
Kilburn, C.R.J., 2015. Lava flow hazards and modelling. In: Sigurdsson, H., B. Houghton, H. Rymer et al. (Eds.), The Encyclopedia of Volcanoes. 2nd Ed. pp. 957-969. Academic Press.
Pallister, J.S., D.J. Schneider, J.P. Griswold, R.H. Keeler, W.C. Burton, C. Noyles, C.G. Newhall and A. Ratdomopurbo, 2013. Merapi 2010 eruption—chronology and extrusion rates monitored with satellite radar and used in eruption forecasting. Journal of Volcanology and Geothermal Research, 261:144-152.
Pallister, J., P. Papale, J. Eichelberger, C. Newhall, C. Mandeville, S. Nakada, W. Marzocchi, S. Loughlin, G. Jolly, J. Ewert and J. Selva, 2019. Volcano observatory best practices (VOBP) workshops – a summary of findings and best-practice recommendations. Journal of Applied Volcanology, 8:2. doi.org/10.1186/s13617-019-0082-8.
Pederson, G.B.M., A. Hoskuldsson, T. Durig and 16 others, 2017. Lava field evolution and emplacement dynamics of the 2014-15 basaltic fissure eruption at Holuhrain, Iceland. Journal of Volcanology and Geothermal Research, 340:155-169.
Pinkerton, H., G.E. Norton, J.B. Dawson and D.M. Pyle, 1995. Field observations and measurements of the physical properties of oldoinyo lengai alkali carbonatite lavas, November 1988. In: Bell K. and J. Keller (eds.), Carbonatite Volcanism. IAVCEI Proceedings in Volcanology, vol 4. Springer. doi.org/10.1007/978-3-642-79182-6_3
Thordarsson, T. and S. Self, 1993. The Laki (Skaftár Fires) and Grímsvötn eruptions in 1783–1785. Bulletin of Volcanology, 55:233-263.
Tsang, S.W.R. and J.M. Lindsay, 2020. Lava flow crises in inhabited areas part I: lessons learned and research gaps related to effusive, basaltic eruptions. Journal of Applied Volcanology, 9:9. doi.org/10.1186/s13617-020-00096-y
Tsang, S.W.R., J.M. Lindsay, B. Kennedy and N.I. Deligne, 2020. Thermal impacts of basaltic lava flows to buried infrastructure: workflow to determine the hazard. Journal of Applied Volcanology, 9:8. doi.org/10.1186/s13617-020-00098-w.
Tuffen, H., M.R. James, J.M. Castro and I. Schipper, 2013. Exceptional mobility of an advancing rhyolitic obsidian flow at Cordon Caulle volcano in Chile. Nature, 4:2709. doi.org/10.1038/ncomms3709.
Turner, N.R., P.L. Perroy and K. Hon, 2017. Lava flow hazard prediction and monitoring with UAS: a case study from the 2014-15 Pāhoa lava flow crisis, Hawai’i. Journal of Applied Volcanology, 6:17. doi.org/10.1186/s13617-017-0068-3.
UNDRR, 2015. Sendai Framework for Disaster Risk Reduction 2015-2030. United Nations Office for Disaster Risk Reduction (UNDRR). Accessed 12 October 2020.
Vicari, A., G. Ganci, B. Behncke, A. Cappello, M. Neri and C. Del Negro, 2011. Near‐real‐time forecasting of lava flow hazards during the 12–13 January 2011 Etna eruption. Geophysical Research Letters, 38, L13317. doi.org/10.1029/2011GL047545.
Wantim, M.N., C. Bonadonna, C.E. Gregg, S. Menoni, C. Frischknecht, M. Kervyn and S.N. Aynghe, 2018. Forensic assessment of the 1999 Mount Cameroon eruption, West-Central Africa. Journal of Volcanology and Geothermal Research, 358:13-30.