Regional variability in the frequency and magnitude of large explosive volcanic eruptions

Abstract

Quantifying the frequency at which volcanic eruptions of different size occurs is important for hazard assessment. Volcanic records can be used to estimate the recurrence rate of large-magnitude eruptions (magnitude ≥4), but recording biases that impact data completeness complicate analysis. To overcome these biases, we conceptualize the volcanic record as a series of individual and unique time series associated by a common behavior. Thus, we approach issues of completeness on a volcano-by-volcano basis and use a hierarchical Bayesian approach to characterize the common frequency-magnitude (f-M) behavior for different groups of volcanoes. We identify variations in the f-M relationship between different volcano types and between different volcanic arcs. By accounting for systematic under-recording in the volcanic record, we also calculate the global recurrence rates for large-magnitude eruptions during the Holocene, which are similar to previous estimates. However, higher recurrence rates for smaller-magnitude events are observed, which is a result of our adjustments for data completeness. Quantifying how the f-M relationship varies between different groups of volcanoes provides an opportunity to understand how the tectonic setting influences f-M behavior, which is important to quantify long-term regional volcanic hazard.

The global magnitude–frequency relationship for large explosive volcanic eruptions

“…Compared to Sheldrake and Caricchi (2017), who use the same version of LaMEVE as we do (although without our update, see section 3), our return periods for M ≤ 7 are much longer. Sheldrake and Caricchi (2017) noted the rounding issue, and attributed it, as we do, to rounding to the nearest integer. They also binned their magnitudes, but centred on the 0.5's, not the integers; i.e.…”

“…Second, the stationarity of eruption Table 6, p14, Holocene, u = 4.0; see their Figure 10 for confidence intervals. Sheldrake and Caricchi (2017): Based on the text above their Figure 4, applying the percentage differences to the values from Pyle (1995).…”

“…From this perspective, the frequency of very large explosive eruptions is of particular importance due to the potential for such eruptions to have not only regional but also global environmental and societal effects. Although the magnitude-frequency relationship for large-magnitude eruptions has been well-studied (Pyle, 1995;Siebert et al, 2010;Deligne et al, 2010;Sheldrake and Caricchi, 2017), some uncertainty remains, while the relationship for the largest-magnitude explosive eruptions is not well known (although see Mason et al, 2004).…”

Evaluating relative tephra fall hazard and risk in the Asia-Pacific region

“…This allows more detailed, potentially time dependent, analysis of trends such as clustering or cyclic eruption activity at individual volcanoes, and permits shorter term hazard and risk assessments that can be updated if unrest is observed. While clearly this is not feasible for a large number of volcanoes, further improvements in the characterization of frequency-magnitude relationships from incomplete eruption catalogues, particularly those that use innovative statistical methods (e.g., Rougier et al, 2016) and incorporate the tectonic or volcanic setting (e.g., Sheldrake and Caricchi, 2016), will be invaluable.…”

Magmatic Landscape Construction

“…And for very large Journal of Geophysical Research: Earth Surface 10.1029/2017JF004369 eruptions, the small number of recorded events makes recurrence rates more uncertain. Rougier et al (2018) estimate the return period of M = 8 eruptions at 17 kyr with 95% confidence limits of +48 and −5.2 kyr, a decrease from prior calculations (Mason et al, 2004;Sheldrake & Caricchi, 2017).…”