Madden J, Murray TL, Carle WJ, Cirillo MA, Furgione LK, Trimpert MT, and Hartig L (2008) Alaska interagency operating plan for volcanic ash episodes, p 52

Newhall C, Solidum RU (2017) Volcanic hazard communication at Pinatubo from 1991 to 2015. Springer, Berlin, Heidelberg, pp 1–15. https://doi.org/10.1007/11157_2016_43 Examples include Hawaii, Iceland and Yellowstone. If the plate overlying the plume moves away from the hot spot, a new volcano can be formed. The previous volcano cools to become dormant and eventually extinct. This sequence forms a volcanic chain such as with the Hawaiian Islands David PA, Greenstein S (1990) The economics of compatibility standards: an introduction to recent research. Econ Innov New Technol 1:3–41Small changes in the shape of a volcano such as bulging may indicate that magma is rising. Accurately measuring the summit and slopes of a volcano is one of the most important tools used for forecasting an eruption. Temperature changes in surface lakes or the groundwater near a volcano also can be a valuable early detection tool, although not all large changes in temperature are related to volcanic eruptions.

Guston DH (2001) Boundary organizations in environmental policy and science: an introduction. Sci Technol Hum Values 26(4):399–408. https://doi.org/10.1177/016224390102600401 Since the turn of the century, increasing standardisation across national VALS has occurred, facilitating national adaptations to better fit volcanism type and national emergency management protocols. The growing number of nationally adopted VALS is illustrated, for example, by the 2006 standardisation of USGS VALS, in which three different VALS were replaced by the standard VALS now used at all five volcano observatories (Fearnley 2011). Similarly, until recently, New Zealand operated two systems: one designed for the hazards expected at frequently active cone volcanoes and another for reawakening volcanoes. Both were based on numbered levels (from 0 to 5) (GNS 2010). In 2014, however, these were revised into a single VALS for ground-based hazards (Potter et al. 2017). Many observatories continue to deal with more than one VALS during a crisis. Both the US and New Zealand alert levels are decided by the current activity of a volcano; they do not provide action or advice to users for mitigative action. In contrast, the Japanese VALS states the measures to be taken by specifying areas of danger, indicating the extent of evacuation and outlining expected volcanic activity (Japan Meteorological Agency 2010). In Indonesia, the Center for Volcanology and Geological Hazard Mitigation (CVGHM) uses VALS to outline the potential impact of the volcanic behaviour on surrounding communities, integrate capacity building in communities and assist in the implementation of actions during volcanic eruptions according to alert level (Andreastuti et al. 2017). Montserrat Volcano Observatory has designed an VALS whereby certain designated zones on the island are assigned an alert level that determines access restrictions to those zones. These examples demonstrate the diversity in the style, design and use of VALS to cater for the particularly requirements of each observatory; in the case of Monserrat, the need to make sure people move to safe zones or avoid dangerous ones (Donovan and Oppenheimer 2015; Donovan et al. 2012). VALS used in developing countries are more likely to provide advice on mitigative action or evacuations to civil authorities and emergency managers. The many factors involved in designing a VALS include what information is provided, whether actions are recommended, the style of warning (actual or forecast) and the number of VALS used. Different countries may also offer differing capacities for decision-making in response to volcanic activity, moving from an extreme end-member where the alert level de facto establishes actions, through to the public authorities making the decision in isolation from the scientists. GNS (2010) Volcano alert levels explained. http://www.gns.cri.nz/what/earthact/volcanoes/alertl_1.html. Accessed 05/01/2010s 2010 Applying this concept to analyse the use of VALS offers to clarify the role of underlying drivers in the way that volcanic crisis communication has operated in practice both prior to and during volcanic emergencies from 2007 to 2009. The USGS VHP is used as a case study. Operating across five observatories, which have been established to monitor and research volcanic phenomena and risk that manifest a wide range of behaviours in different parts of the world, this program engages with a range of different cultures, communities and user and stakeholder groups. Between 2007 and 2009, 93 semi-structured interviews Footnote 3 were conducted with both observatory scientific personnel and relevant user groups associated with the AVO, CVO, Hawaii Volcano Observatory (HVO), Long Valley Volcano Observatory (LVO) (re-established in 2012 as the California Volcano Observatory CalVo), and Yellowstone Volcano Observatory (YVO). In addition to scientists employed in observatories, interview participants were drawn from user groups including other federal agencies such as US Emergency Managers (country and state levels), the National Weather Service, US Forest and National Park managers, the Federal Aviation Administration, Volcano Ash Advisory Centre staff, local town managers and police and also included local and national media (for a full list, see Fearnley ( 2011, pp. 108–109)). Mileti D (1999) Disasters by design: a reassessment of natural hazards in the United States. Joseph Henry PressFearnley C, McGuire W, Davies G, Twigg J (2012) Standardisation of the USGS volcano alert level system (VALS): analysis and ramifications. Bull Volcanol 74:2023–2036 Aspinall WP, Loughlin SC, Michael FV, Miller AD, Norton GE, Rowley KC, Sparks RSJ, Young SR (2002) The Montserrat volcano observatory: its evolution, organization, role and activities. Geol Soc Lond Mem 21:71–91 Casale M, Drimie S, Quinlan T, Ziervogel G (2009) Understanding vulnerability in southern Africa: comparative findings using a multiple-stressor approach in South Africa and Malawi. Reg Environ Chang 10(2):157–168

Donovan AR, Oppenheimer C (2015) Modelling risk and risking models: the diffusive boundary between science and policy in volcanic risk management. Geoforum 58:153–165 It has been well established that VALS are designed to provide a ‘bridge’ between the scientific data on risk gathered through the monitoring process and the mitigation decisions and actions involved in the practical management of and response to the relevant hazards (Fearnley 2011; Gardner and Guffanti 2006). There has been very little research to date, however, concerned with the use of VALS to facilitate the communication of the scientific assessment of risk to those required to make practical management and response decisions. Recent exceptions have focused on the issues that arise around the distribution of tasks and decision-making responsibilities between the volcano scientists responsible for deciding alert levels, and the decision-makers who rely on the alert levels when making decisions during volcanic crises that have significant social consequences (e.g. Andreastuti et al. 2017; Hill et al. 2017; Newhall and Solidum 2017; Potter et al. 2017). Fearnley ( 2013) established that in practice, the high levels of both scientific uncertainty and risk so characteristic of volcanic activity have required that scientists consult locally and take social and political factors into account when deciding alert levels. Fearnley concludes that more transparently deliberative approaches that bring scientists and decision-makers together to agree on alert levels would have the potential to legitimise a greater level of coproduction of knowledge, and increase shared understanding of the uncertainties and risks involved on all sides. More recently, Papale ( 2017) appears to take issue with this suggestion. Citing the “principle of separation of roles”, he proposes instead that “scientists should base their evaluations exclusively on scientific knowledge, providing decision-makers with clear, unambiguous information that they can use to fulfil their societal and political mandates” (Papale 2017, p. 4). He maintains that this information should consist of probabilistic forecasts, which he finds to be “in a form most suited to provide decision-makers with the realistic picture for their subsequent decisions” (Papale 2017, p. 4). Papale concludes that VALS should be replaced by a “rational approach, in which varied expertise is harnessed in a coordinated effort, uncertainties are fully recognised and quantified, communications are unambiguous, and responsibilities reflect the social role and societal mandate of all groups involved” (Papale 2017, p. 4).Potter SH (2014) Communicating the status of volcanic activity in New Zealand, with specific application to caldera unrest: a thesis presented in partial fulfilment of the requirements for the degree of Doctorate in Emergency Management at Massey University, Wellington. Massey University, New Zealand Gieryn TF (1999) Cultural boundaries of science: credibility on the line. University of Chicago Press For VALS to be effective, assessments conducted by scientists must be relevant to the needs of the key decision makers. The relevance requirement has been found to drive associated demands for timeliness and for simple accessible alert information (Sarkki et al. 2013; Parker and Crona 2012). With reference to VALS, this includes demand for timely simple and accessible alert information, that is usable subject to a range of contingent factors. Timeliness