Analog experiments of lava flow emplacement

Abstract

Laboratory experiments that simulate lava flows have been in use by volcanologists for many years. The behavior of flows in the lab, where "eruption" parameters, material properties, and environmental settings are tightly controlled, provides insight into the influence of various factors on flow evolution. A second benefit of laboratory lava flows is to provide a set of observations with which numeri− cal models of flow emplacement can be tested. Models of lava flow emplacement vary in mathematical approach, physical assumptions, and computational cost. Nonetheless, all models require thorough testing and evaluation, and laboratory experiments produce an ex− cellent test for models. This paper provides a primer on modern analog laboratory lava flow experiments. It reviews scaling considerations and provides quanti− tative information meant to guide future experimentalists in designing their experiments to be relevant to natural processes. Traditional and novel laboratory techniques are described, including a discussion of current limitations. New insights from recent experiments high− light the impact of topographic conditions and highlight the importance of considering bed roughness, major obstacles, and slope breaks. The influence of episodic or non−uniform effusion rate is demonstrated through recent experimental works. Lastly, the paper discusses sev− eral open questions about lava flow emplacement and the ways in which future improvements in experimental methods, such as the abil− ity to utilize three−phase suspensions and materials with complex rheologies and to image the interior of flows could help answer these.

Rheology of melts from the colli albani volcanic district (Italy): a case study

“…However, natural magmas and lavas are a mixture of a liquid melt, solid particles and gas bubbles (Lev et al 2019). This, together with the species of volatiles, strain and shear-rates generated by the geological setting of a volcano, results in a complex melt rheology (i.e.…”

Wall Fracturing Versus Mechanical Instability as Competing Intrusion Mechanisms of Dikes: Insights From Laboratory Experiments

“…The present experiments were thus run by varying the liquid injection velocities in the range 1.99 × 10 −3 to 3.32 × 10 −2 m s −1 which correspond to volumetric flow rates (VFR) of 0.100 and 1.670 ml s −1 , respectively. It is noteworthy that the average velocity of magma flows plays a decisive role in setting the condition of magma propagation with or without solidification, which can be evaluated in terms of the Péclet number ( Pe ) (R. W. Griffiths, 2000; Lev et al., 2019). Pe is the ratio of heat transfer by fluid advection to the heat transfer by thermal conduction, expressed as $$\frac{UL}{\kappa }$$, where U is the mean flow velocity, L is the characteristic length scale, and κ is the thermal diffusivity of magma (R. W. Griffiths, 2000; Lev et al., 2019).…”

“…It is noteworthy that the average velocity of magma flows plays a decisive role in setting the condition of magma propagation with or without solidification, which can be evaluated in terms of the Péclet number ( Pe ) (R. W. Griffiths, 2000; Lev et al., 2019). Pe is the ratio of heat transfer by fluid advection to the heat transfer by thermal conduction, expressed as $$\frac{UL}{\kappa }$$, where U is the mean flow velocity, L is the characteristic length scale, and κ is the thermal diffusivity of magma (R. W. Griffiths, 2000; Lev et al., 2019). A Pe >> 1 condition implies that the flows are fast enough to transport heat dominantly by advection, keeping the conductive heat diffusion and cooling as a non‐competing process, whereas a condition of Pe << 1 allows the magma sufficient time to cool by conductive heat transfer, leading to its solidification (Lev et al., 2019).…”

Opportunities for Characterizing Geological Flows Using Magnetic Resonance Imaging

“…Sedimentologists often study deposition and erosion processes in a laboratory flume (e.g., Baar et al., 2018 ; Pohl et al., 2020 ). Volcanologists use analog experiments to study all the various components of the magmatic system, from the magma reservoir ( Galland et al., 2014 ) and plumbing system ( Taisne et al., 2011 ) to eruptions and their products ( Del Bello et al., 2017 ; Iverson et al., 2010 ; Lev et al., 2019 ; Lube et al., 2015 ).…”