Abstract DOWNFLOW is a probabilistic code for the simulation of the area covered by lava flows. This code has been used extensively for several basaltic volcanoes in the last decade, and a review of some applications is presented. DOWNFLOW is based on the simple principle that a lava flow tends to follow the steepest descent path downhill from the vent. DOWNFLOW computes the area possibly inundated by lava flows by deriving a number, N , of steepest descent paths, each path being calculated over a randomly perturbed topography. The perturbation is applied at each point of the topography, and ranges within the interval ±Δ h . N and Δ h are the two basic parameters of the code. The expected flow length is constrained by statistical weighting based on the past activity of the volcano. The strength of the code is that: (i) only limited volcanological knowledge is necessary to apply the code at a given volcano; (ii) there are only two (easily tunable) input parameters; and (iii) computational requirements are very low. However, DOWNFLOW does not provide the progression of the lava emplacement over time. The use of DOWNFLOW is ideal when a large number of simulations are necessary: for example, to compile maps for hazard and risk-assessment purposes.

Abstract FLOWGO is a one-dimensional model that tracks the thermorheological evolution of lava flowing down a channel. The model does not spread the lava but, instead, follows a control volume as it descends a line of steepest descent centred on the channel axis. The model basis is the Jeffreys equation for Newtonian flow, modified for a Bingham fluid, and a series of heat loss equations. Adjustable relationships are used to calculate cooling, crystallization and down-channel increases in viscosity and yield strength, as well as the resultant decrease in velocity. Here we provide a guide that allows FLOWGO to be set up in Excel. In doing so, we show how the model can be executed using a slope profile derived from Google™ Earth. Model simplicity and ease of source-term input from Google™ Earth means that this exercise allows (i) easy access to the model, (ii) quick, global application and (iii) use in a teaching role. Output is tested using measurements made for the 2010 eruption of Piton de la Fournaise (La Réunion Island). The model is also set up for rapid syneruptive hazard assessment at Piton de la Fournaise, as we show using the example of the response to the June 2014 eruption.

We have organized ten National Aeronautics and Space Administration (NASA)–sponsored planetary volcanology field workshops on Hawai‘i since 1992, providing an opportunity for almost 140 NASA-funded graduate students, postdocs, and junior faculty to view basaltic volcano features up close in the company of both terrestrial and planetary volcanologists. Most of the workshops have been thematic, for example, concentrating on large structural features (rift zones and calderas) or lava flows, or features best viewed in high-spatial-resolution data, but they always include a broad set of topics. The workshops purposely involve long field days—an appreciation of scale is important for planetary scientists, particularly if they are or will be working with slow-moving rovers. Our goals are to give these young scientists a strong background in basaltic volcanology and provide the chance to view eruptive and volcano-structural features up close so that they can compare the appearance of these features in the field to their representations in state-of-the-art remote-sensing images, and relate them in turn to analogous planetary features. In addition, the workshop enables the participants to start a collection of field photographs and observations that they can use in future research and teaching. An added benefit is that the participants interact with each other, forging collaborations that we hope will persist throughout their careers.