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Map of Sunset Crater area. Lava fields and vent areas of the Sunset eruption are shown in black. Topographic lines (gray) are in 500-foot contours. Isopach contours (black) are in centimeters. The area with more than 30 cm of fallout and at an elevation above 1890 masl (6200 ft) is shaded in gray to show the area of prime agricultural land and high density prehistoric settlement that had to be abandoned.
Source publication
Two ∼ 900 BP cinder-cone eruptions in the American Southwest affected prehistoric human populations in different ways, mostly because of differences in the eruption styles and area affected. Primary pre-eruption cultural factors that may have led to successful adaptation to the eruptions include decision-making at the family or household level, low...
Contexts in source publication
Context 1
... It is the youngest of about 600 cinder cones in the San Francisco volcanic field, which covers an area of approximately 5000 km 2 along the southern margin of the Colorado Plateau ( Tanaka et al., 1986). Sunset Crater erupted into a volcanic landscape marked by abundant cinder cones with flat areas, mostly underlain by lava flows, between them (Fig. 2). Elevations in this area range between 1800 and 2200 masl and contain ponderosa pine (Pinus ponderosa) forest at elevations above 2040 masl (6700 ft), piñon- juniper (Pinus edulis/Juniperus monospermae) woodlands between 1890 and 2040 masl (6200-6700 ft), and desert grasslands below this. Vegetation is directly correlated with ...
Context 2
... use Amos (1986), Holm and Moore (1987), Holm (1987), and our own work to describe the Sunset Crater eruption sequence. Sunset Crater began with the opening of a 10-km-long fissure stretching from where Sunset Crater is now southeast to Vent 512 (Fig. 2). This fissure eruption deposited two distinct ashfall layers. The fissure is clearly traced, even where the spatter ramparts are not apparent, because it oxidized later cinder-fall to a red-brown color. It appears to have been discontinuous, with breaks of tens of meters to 2 km, and in some places, the breaks separate en-echelon ...
Context 3
... the eruption, an area of N2300 km 2 was covered by N1 cm of fallout (Fig. 2), with around 400 km 2 beneath at least 30 cm of cinders ( Hooten et al., 2001). Another 8 km 2 was underneath 2-30 m of lava. The cinders blew in the winds, making dune forms still visible today. By reducing evaporation, they probably led to increased groundwater supply and the appearance of new springs. Some spring deposits are ...
Context 4
... also indicate that N15 cm cinder cover is detrimental to agriculture, and that maize will not grow in cinders deeper than 20- 25 cm. Cinders continue to harm agriculture at Parícutin; 40 years after the eruption, vegetation in the areas with N15 cm fallout had still not recovered (Rees, 1979). The 30-cm isopach, which encloses about 400 km 2 (Fig. 2), is a very conservative measure of the area around Sunset Crater that was not farmable. Structures within and beyond this area were also heavily damaged by tephra fall, with most probably sustaining roof and wall ...
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Citations
... There are only a few published studies that attempt to understand the human connections and uses of this unique landscape. Most have been archeological studies (Elson & Ort, 2006;Hintzman, 2012;Ort et al., 2008aOrt et al., , 2008b. These studies have used the available archeological data and information on the volcanic eruption to interpret the American Indian lifestyles and behavioral responses that occurred before, during, and after the Little Springs event. ...
... The Southern Paiute interpretation of the significance of the Little Springs Lava Flow and the Uinkaret Volcanic Field varies greatly from the published archeological interpretations. While Southern Paiutes and archeologists are in agreement that Indian people constructed the trails and associated structures, the archeologists have maintained that this area was not a ceremonial area as Southern Paiute representatives have stated, but instead it was a place Indian people fled from during the time of the eruption (Elson & Ort, 2006;Hintzman, 2012;Ort et al., 2008aOrt et al., , 2008b. ...
... This is in contrast with the views of archeologists and other researchers. According to Northern Arizona University volcanologist Michael Ort, the entire Little Springs volcanic event could have happened over a span of as little as a few days to a week (Ort et al., 2008b). If true, this would not have allowed the Indian people to prepare a response in anticipation of the event. ...
This is a study of a group of people living in south-central Slovakia who wish to reconnect with their ancestral land. This group has decided to return to the abandoned cultural landscape in former hamlets. The area they are returning to, like many other similar areas around Europe, is characterized by demographic change through outmigration by young generations and aging populations. To facilitate their return, a group of anthropologists have conducted research of original adaptation strategies, historical migrations, and demographic changes in selected localities. At the same time, the areas’ last inhabitants began to revitalize cemeteries—symbolic places. The anthropologists facilitated this restoration process by conducting oral histories, developing maps of traditional areas, and compiling ethnohistorical research data. The abandoned cemeteries acquired a new function after their restoration—they speak to the public as an environmental argument for the fragility of landscape sustainability.
... There are only a few published studies that attempt to understand the human connections and uses of this unique landscape. Most have been archeological studies (Elson & Ort, 2006;Hintzman, 2012;Ort et al., 2008aOrt et al., , 2008b. These studies have used the available archeological data and information on the volcanic eruption to interpret the American Indian lifestyles and behavioral responses that occurred before, during, and after the Little Springs event. ...
... The Southern Paiute interpretation of the significance of the Little Springs Lava Flow and the Uinkaret Volcanic Field varies greatly from the published archeological interpretations. While Southern Paiutes and archeologists are in agreement that Indian people constructed the trails and associated structures, the archeologists have maintained that this area was not a ceremonial area as Southern Paiute representatives have stated, but instead it was a place Indian people fled from during the time of the eruption (Elson & Ort, 2006;Hintzman, 2012;Ort et al., 2008aOrt et al., , 2008b. ...
... This is in contrast with the views of archeologists and other researchers. According to Northern Arizona University volcanologist Michael Ort, the entire Little Springs volcanic event could have happened over a span of as little as a few days to a week (Ort et al., 2008b). If true, this would not have allowed the Indian people to prepare a response in anticipation of the event. ...
This chapter elaborates conceptual and theoretical insights to advance a conflict- and power-oriented perspective for a critical conceptualization of environmental communication. To this purpose, the chapter develops and builds upon insights from the anthropology of power and the epistemologies of the South. Within this context, the chapter focuses on the theoretical contributions of Paulo Freire and Eric Wolf to critically approach the relations between communication, power, and conflicts within social-ecological relations. Empirically, the chapter offers an analysis of struggles for water justice and water democracy in Chile which is based on interviews, observations, and analysis of documents conducted during fieldwork in three regions and rural areas of Chile. The chapter argues for a critical theorizing of environmental communication to better understand and explain the meanings of normative views of environmental communication, and to also understand how such normative views cannot be separated from the interests of subjects situated in contingent social-ecological relations and conflicts.
... There are only a few published studies that attempt to understand the human connections and uses of this unique landscape. Most have been archeological studies (Elson & Ort, 2006;Hintzman, 2012;Ort et al., 2008aOrt et al., , 2008b. These studies have used the available archeological data and information on the volcanic eruption to interpret the American Indian lifestyles and behavioral responses that occurred before, during, and after the Little Springs event. ...
... The Southern Paiute interpretation of the significance of the Little Springs Lava Flow and the Uinkaret Volcanic Field varies greatly from the published archeological interpretations. While Southern Paiutes and archeologists are in agreement that Indian people constructed the trails and associated structures, the archeologists have maintained that this area was not a ceremonial area as Southern Paiute representatives have stated, but instead it was a place Indian people fled from during the time of the eruption (Elson & Ort, 2006;Hintzman, 2012;Ort et al., 2008aOrt et al., , 2008b. ...
... This is in contrast with the views of archeologists and other researchers. According to Northern Arizona University volcanologist Michael Ort, the entire Little Springs volcanic event could have happened over a span of as little as a few days to a week (Ort et al., 2008b). If true, this would not have allowed the Indian people to prepare a response in anticipation of the event. ...
The Little Springs Lava Flow is the remnant of an active volcano located in northern Arizona. Southern Paiutes and the scientific community dispute about the Paiute response to this eruption. Paiutes stipulate that this volcano is a ceremonial landscape where religious leaders physically interacted during eruption and subsequently built a series of trails for ceremony. This interpretation contrasts with that of the scientific community, who maintain that volcanoes are dangerous to humans, and therefore Paiutes would have left in fear during the eruption. This chapter explains this debate and how Paiutes are challenging the scientists in order to communicate their environmental heritage.
... There are only a few published studies that attempt to understand the human connections and uses of this unique landscape. Most have been archeological studies (Elson & Ort, 2006;Hintzman, 2012;Ort et al., 2008aOrt et al., , 2008b. These studies have used the available archeological data and information on the volcanic eruption to interpret the American Indian lifestyles and behavioral responses that occurred before, during, and after the Little Springs event. ...
... The Southern Paiute interpretation of the significance of the Little Springs Lava Flow and the Uinkaret Volcanic Field varies greatly from the published archeological interpretations. While Southern Paiutes and archeologists are in agreement that Indian people constructed the trails and associated structures, the archeologists have maintained that this area was not a ceremonial area as Southern Paiute representatives have stated, but instead it was a place Indian people fled from during the time of the eruption (Elson & Ort, 2006;Hintzman, 2012;Ort et al., 2008aOrt et al., , 2008b. ...
... This is in contrast with the views of archeologists and other researchers. According to Northern Arizona University volcanologist Michael Ort, the entire Little Springs volcanic event could have happened over a span of as little as a few days to a week (Ort et al., 2008b). If true, this would not have allowed the Indian people to prepare a response in anticipation of the event. ...
This is a study of the communication of environmental risk associated with the planned removal of arsenic from the copper mining fields in Riddarhyttan, central Sweden. The study was implemented using in-depth interviews with community residents and representatives from the local, regional, and national governments, as well as walk-and-talk sessions near contaminated grounds to learn about the value of these places to local people and their reflections on risk. The study identified how local residents had to navigate between messages from authorities that touching stones could be life threatening at the same time as they were told that risk was non-existent. This resulted in mixed and affective feelings regarding place, community, and the role the copper industry had played in the past. The case is an illuminating example of how perception and communication is embedded in the social and cultural reality of local communities.
... There are only a few published studies that attempt to understand the human connections and uses of this unique landscape. Most have been archeological studies (Elson & Ort, 2006;Hintzman, 2012;Ort et al., 2008aOrt et al., , 2008b. These studies have used the available archeological data and information on the volcanic eruption to interpret the American Indian lifestyles and behavioral responses that occurred before, during, and after the Little Springs event. ...
... The Southern Paiute interpretation of the significance of the Little Springs Lava Flow and the Uinkaret Volcanic Field varies greatly from the published archeological interpretations. While Southern Paiutes and archeologists are in agreement that Indian people constructed the trails and associated structures, the archeologists have maintained that this area was not a ceremonial area as Southern Paiute representatives have stated, but instead it was a place Indian people fled from during the time of the eruption (Elson & Ort, 2006;Hintzman, 2012;Ort et al., 2008aOrt et al., , 2008b. ...
... This is in contrast with the views of archeologists and other researchers. According to Northern Arizona University volcanologist Michael Ort, the entire Little Springs volcanic event could have happened over a span of as little as a few days to a week (Ort et al., 2008b). If true, this would not have allowed the Indian people to prepare a response in anticipation of the event. ...
Anthropological findings and symbolic activities of native populations can be argumentative tools in environmental communication. This chapter presents the ethnography research and assistance of anthropologists in the re-adaptation of the new mountain generation in Vrchár communities in Slovakia, Central Europe. Here, in the second half of twentieth century, several generations were evicted from their original surroundings. The anthropologists compiled an inventory of the current state of local culture in outlying locations. They subsequently used a mixed method to analyze the consequences of interrupting generational transmission and created a model for sustainable transmission of local culture. The new generation adapts Traditional Ecological Knowledge (TEK) as lived heritage and periodically presents newly learned knowledge of symbolic events. This symbolic reference to sustainability constitutes important argumentation in environmental communication with multiple stakeholders.
... There are only a few published studies that attempt to understand the human connections and uses of this unique landscape. Most have been archeological studies (Elson & Ort, 2006;Hintzman, 2012;Ort et al., 2008aOrt et al., , 2008b. These studies have used the available archeological data and information on the volcanic eruption to interpret the American Indian lifestyles and behavioral responses that occurred before, during, and after the Little Springs event. ...
... The Southern Paiute interpretation of the significance of the Little Springs Lava Flow and the Uinkaret Volcanic Field varies greatly from the published archeological interpretations. While Southern Paiutes and archeologists are in agreement that Indian people constructed the trails and associated structures, the archeologists have maintained that this area was not a ceremonial area as Southern Paiute representatives have stated, but instead it was a place Indian people fled from during the time of the eruption (Elson & Ort, 2006;Hintzman, 2012;Ort et al., 2008aOrt et al., , 2008b. ...
... This is in contrast with the views of archeologists and other researchers. According to Northern Arizona University volcanologist Michael Ort, the entire Little Springs volcanic event could have happened over a span of as little as a few days to a week (Ort et al., 2008b). If true, this would not have allowed the Indian people to prepare a response in anticipation of the event. ...
This chapter discusses an environmental communication approach, using certain Indigenous place names as examples of how residents of communities around Iliamna Lake, Alaska, not only use place names to convey environmental and spatial information, but also to emphasize the temporal and spiritual relationships between the people and the land. Place names and stories about these places often reveal local histories and affirm cultural ethics. Elders sharing their feelings and stories about these places with younger generations affirm the residents’ connection to the streams, lakes, and other landmarks in the Iliamna Lake area. Participating in daily activities and sharing oral traditions of the landscape are at the core of the environmental communication used by residents of Iliamna Lake communities to live in harmony with nature.
... The youngest volcanic rocks in the UVF were produced when a double cinder cone (or single mountain) formed about 3 km (2 mi) south of Mount Trumbull (Figure 17). The The Little Spring Lava Flow event is dated with archaeology at about 1075 AD [59,60]. Although standard volcanic dating procedures were followed, they largely failed to provide a useful eruption date, thus the estimated dates for the flow are based on Indian pottery found in Indian made lava/pottery rocks, called sherd rocks, which are volcanic scoria containing pottery fragments (Figures 18 and 19). ...
... The lava pottery stones, or sherd rocks, subsequently were moved some distance from the lava flow and made into a series of structures that were used in ceremony according to the Paiute representatives. The Little Spring Lava Flow event is dated with archaeology at about 1075 AD [59,60]. Although standard volcanic dating procedures were followed, they largely failed to provide a useful eruption date, thus the estimated dates for the flow are based on Indian pottery found in Indian made lava/pottery rocks, called sherd rocks, which are volcanic scoria containing pottery fragments (Figures 18 and 19). ...
... The Little Spring Lava Flow event is dated with archaeology at about 1075 AD [59,60]. Although standard volcanic dating procedures were followed, they largely failed to provide a useful eruption date, thus the estimated dates for the flow are based on Indian pottery found in Indian made lava/pottery rocks, called sherd rocks, which are volcanic scoria containing pottery fragments (Figures 18 and 19). ...
A new volcano erupted in the eleventh century AD in the San Francisco volcanic field, which has as many as 80 old volcanoes and 600 eruption cones all centered around Flagstaff, Arizona. This volcanic landscape has been a cultural center for Native American spiritual activities for up to 23,000 years. During that time, they have come to perceive volcanoes as earth navels and thus places where the earth is reborn. For this reason, the emergence of an active volcano, called Sunset Crater, drew pilgrims and resulted in the construction of ceremonial and support communities surrounding a place called Wupatki. This paper is partially based on a 2004 study funded by the U.S. National Park Service, which produced 80 ethnographic interviews with representatives of six Native American ethnic groups composed of 12 tribes and pueblos. The analysis is informed by a total of 23 ethnographic studies of volcanoes conducted with Native Americans by the authors. In all studies, Native American participants conveyed that they have cultural connections with volcanoes that derive from their Creation-based knowledge of the Earth as being alive and volcanoes being its rebirth. Traditional cultural information is critical to park management and compliance with various laws, regulations, executive orders, and policies so that park managers can better address tribal requests for continued access, use, and interpretation of park natural resources. Native Americans involved in our NPS ethnographic studies agreed that it is not necessary for the NPS to accept as true what Native Americans believe, but it is essential to tell in park interpretative settings both stories side by side with equal accuracy.
... This was repeated for oneto four-dimensional configurations, and the configuration with the lowest dimensionality and an unexplained variation of less than 10% was selected. Ordinated scores were Procrustes rotated (Oksanen et al. 2019) for maximum correlation with the tree trait variables (Appendix S1: Fig. S2). Axis scores were then used in the structural model as community response variables. ...
... Multivariate matrices were calculated using the ecodist package (Goslee and Urban 2007). PERMANOVA, Mantel tests, and the ordination with Procrustes rotations were executed using the vegan package (Oksanen et al. 2019). Structural equation modeling (SEM) was performed using the lavaan (Rosseel 2012) and tidygraph (Pedersen 2020) packages. ...
Genetic variation in foundation tree species can strongly influence communities of trophic‐dependent organisms, such as herbivorous insects, pollinators, and mycorrhizal fungi. However, the extent and manner in which this variation results in unexpected interactions that reach trophic‐independent organisms remains poorly understood, even though these interactions are essential to understanding complex ecosystems. In pinyon–juniper woodland at Sunset Crater (Arizona, USA), we studied pinyon (Pinus edulis) that were either resistant or susceptible to stem‐boring moths (Dioryctria albovittella). Moth herbivory alters the architecture of susceptible trees, thereby modifying the microhabitat beneath their crowns. We tested the hypothesis that this interaction between herbivore and tree genotype extends to affect trophic‐independent communities of saxicolous (i.e., growing on rocks) lichens and bryophytes and vascular plants beneath their crowns. Under 30 pairs of moth‐resistant and moth‐susceptible trees, we estimated percent cover of lichens, bryophytes, and vascular plants. We also quantified the cover of leaf litter and rocks as well as light availability. Four major findings emerged. (1) Compared to moth‐resistant trees, which exhibited monopodial architecture, the microhabitat under the shrub‐like susceptible trees was 60% darker and had 21% more litter resulting in 68% less rock exposure. (2) Susceptible trees had 56% and 87% less cover, 42% and 80% less richness, and 38% and 92% less diversity of saxicolous and plant communities, respectively, compared to resistant trees. (3) Both saxicolous and plant species accumulated at a slower rate beneath susceptible trees, suggesting an environment that might inhibit colonization and/or growth. (4) Both saxicolous and plant communities were negatively affected by the habitat provided by susceptible trees. The results suggest that herbivory of moth‐susceptible trees generated litter at high enough rates to reduce rock substrate availability, thereby suppressing the saxicolous communities. However, our results did not provide a causal pathway explaining the suppression of vascular plants. Nonetheless, the cascading effects of genetic variation in pinyon appear to extend beyond trophic‐dependent moths to include trophic‐independent saxicolous and vascular plant communities that are affected by specific tree–herbivore interactions that modify the local environment. We suggest that such genetically based interactions are common in nature and contribute to the evolution of complex communities.
... Southwestern basaltic volcanoes traditionally were not the subject of extensive hazard and risk assessment; they were assumed-at least implicitly-to not pose a threat. However, physical volcanological studies, partly motivated by interest in the impact of eruptions on pre-Columbian cultures (Ort et al., 2008a(Ort et al., , 2008b and by volcanic hazard assessment for the proposed Yucca Mountain radioactive waste repository (Valentine and Perry, 2009), showed that, in addition to explosive phreatomagmatic eruptions, some basaltic monogenetic eruptions in the region included phases of violent Strombolian to sub-Plinian intensity that produced tephra-laden plumes approaching altitudes of 20 km (Alfano et al., 2019). Most intraplate volcanoes in the Southwest are in sparsely populated areas, and eruptions therefore may present lower threat to human life on the ground (although populations are locally increasing) than those in more densely populated volcanic regions. ...
... Scoria cones and ramparts are dominated by coarse lapilli and bombs with varying degrees of welding (agglomerates). The few volcanoes that have been studied in detail commonly have associated tephra deposits that can extend kilometers to tens of kilometers from source vents and record magmatic volatile-driven explosive activity that includes Strombolian, Hawaiian, violent Strombolian, and sub-Plinian in intensity and style Ort et al., 2008aOrt et al., , 2008bBrowne et al., 2010;Johnson et al., 2014;Alfano et al., 2019;Zawacki et al., 2019). Lava flow fields include 'a'ā and block lavas to pāhoehoe and reflect a wide range of effusion rates and flow dynamics (Figs. ...
... The eruption ended with a phreatic blast at the summit crater. Elson et al. (2011) and Ort et al. (2008a, 2008b use many techniques to argue that the eruption occurred between August of 1084 and March of 1085 CE with the month-level precision based upon the immature corn found in the lava spatter and the lack of springtime reworking of tephra within the sequence (reworking occurred afterward). Brumbaugh et al. (2014) interpret that a 6.5 hours-long earthquake swarm in 2009 recorded a basaltic intrusion at 14-27 km depth ~5 km west of Sunset Crater along a trend parallel to the nearby Mesa Butte fault. ...
The southwestern United States contains numerous monogenetic basaltic volcanoes distributed in intraplate volcanic fields. We review, on a regional scale, our current understanding of the Quaternary basalts with a focus on aspects pertinent to hazard assessment, such as physical volcanology and geochronology, while also summarizing the several petrogenetic conceptual models that have been proposed for the range of local tectonic settings in the region. We count 2229 volcanoes in 37 volcanic fields (including the Pinacate volcanic field, which is mostly in northern Sonora, Mexico). Volcanic landforms are dominantly scoria cones and ramparts with attendant lava fields that have a spectrum of ‘a’ā and blocky to pāhoehoe morphologies, while a small percentage of the volcanoes are maars and tuff cones. Explosive eruption styles that were driven mainly by magmatic volatiles, where they have been studied in detail, included Hawaiian, Strombolian, violent Strombolian, and sub-Plinian activity. The latter two have resulted in substantial fallout deposits that can be traced tens of kilometers from source vents. Phreatomagmatic styles have produced pyroclastic current (mainly pyroclastic surges), ballistic, and fallout deposits. These eruption styles pose hazards to humans when they occur in populated areas and to air travel and regional infrastructure even in sparsely populated areas. All but one of the major volcanic fields (fields that contain ~100 or more Quaternary volcanoes) together form a northwest-southeast–trending band, which we suggest may reflect an influence of plate-boundary-related shearing on melt segregation in the upper mantle along with other factors; this view is consistent with recent global positioning system (GPS) and structural geologic data indicating the influence of dextral motion along the North America-Pacific plate boundary deep inside the Southwest. Of the 2229 Quaternary volcanoes identified, ~548 (25%) have been dated, and only ~15% have been dated with methods such as 40Ar/39Ar and cosmogenic surface exposure methods that are considered optimal for young basalts. Acknowledging the large uncertainty due to the poor geochronological data coverage, we use a simple Poisson model to provide a first-order estimate of recurrence rates of monogenetic volcanoes on the scale of the region as a whole; recurrence rates using our compiled age data set range from 3.74 × 10−4 yr−1 to 8.63 × 10−4 yr−1. These values are only based on dated and mapped volcanoes, respectively, and do not account for undated and buried volcanoes or other uncertainties in the volcano count. The time between monogenetic eruptions in the Southwest is similar to the repose times of some polygenetic volcanoes, which suggests that the regional hazard is potentially commensurate with the hazard from a reawakening stratovolcano such as those in the Cascade Range. Notable in our review is that only a few volcanoes have been the subject of physical volcanological characterization, interpretation, and detailed petrologic study that may elucidate factors such as magma generation, ascent (including time scales), and controls on eruption style.
... Etna (Italy) has experienced some sub-Plinian and Plinian events and is similar in composition to Sunset Crater [38][39][40] . While some Etna MIs do contain significant dissolved CO 2 41 , the CO 2 in Etna MI bubbles has not yet been quantified. Stromboli (Italy) is another mafic volcano that has produced explosive paroxysms, and exsolved CO 2 at depths up to 10 km beneath the crater has been proposed as the trigger for these events based on measured crater plume emissions 42 . ...
The most explosive basaltic scoria cone eruption yet documented (>20 km high plumes) occurred at Sunset Crater (Arizona) ca. 1085 AD by undetermined eruptive mechanisms. We present melt inclusion analysis, including bubble contents by Raman spectroscopy, yielding high total CO2 (approaching 6000 ppm) and S (~2000 ppm) with moderate H2O (~1.25 wt%). Two groups of melt inclusions are evident, classified by bubble vol%. Modeling of post-entrapment modification indicates that the group with larger bubbles formed as a result of heterogeneous entrapment of melt and exsolved CO2 and provides evidence for an exsolved CO2 phase at magma storage depths of ~15 km. We argue that this exsolved CO2 phase played a critical role in driving this explosive eruption, possibly analogous to H2O exsolution driving silicic caldera-forming eruptions. Because of their distinct gas compositions relative to silicic magmas (high S and CO2), even modest volume explosive basaltic eruptions could impact the atmosphere. Mechanisms that drive highly explosive eruptions of low-viscosity magmas, such as at Sunset Crater volcano, remain uncertain. Here, the authors present evidence for an exsolved CO2 phase ~15 km beneath Sunset Crater that was the critical driver of rapid magma ascent leading to the explosive eruption.
