By using BET_VH, we propose a quantitative probabilistic hazard assessment for base surge impact in Auckland, New Zealand. Base surges resulting from phreatomagmatic eruptions are among the most dangerous phenomena likely to be associated with the initial phase of a future eruption in the Auckland Volcanic Field. The assessment is done both in the longterm and in a specific short-term case study, i.e. the simulated pre-eruptive unrest episode during Exercise Ruaumoko, a national civil defence exercise. The most important factors to account for are the uncertainties in the vent location (expected for a volcanic field) and in the run-out distance of base surges. Here, we propose a statistical model of base surge run-out distance based on deposits from past eruptions in Auckland and

The island of Dominica hosts several ignimbrites, including the Roseau Tuff, thought to represent the largest eruption in the Caribbean in the past 200 000 years. The volcanic stratigraphy of the island is poorly understood due to limited outcrops and a paucity of geochemical and geochronological data. The discovery of a new fully accessible exposure of three ignimbrites intercalated with paleosols provides an opportunity to re‐evaluate the current stratigraphic framework of ignimbrite‐forming eruptions on the island. Whole‐rock analyses of pumice clasts from Dominica ignimbrites are andesitic (61–66% SiO2) and in most cases are geochemically indistinguishable. Ignimbrites in the north of the island have less evolved glass compositions (73–75% SiO2) and more mafic orthopyroxene compositions (En > 56) than their southern counterparts (75–78% SiO2; En < 56). Pumice clasts from ignimbrites in southern Dominica have indistinguishable groundmass glass and mineral chemistry, making correlation of these deposits difficult. New (U–Th)/He eruption ages for the southern ignimbrites indicate that at least six separate explosive eruptions occurred between 24 and 61 ka. The non‐unique geochemistry of these deposits, together with the new (U−Th)/He ages, suggests that the large volume inferred for the Roseau Tuff eruption may actually be a composite of six smaller, geochemically homogeneous eruptions.

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[1] Long-term crustal flow is computed with a kinematic finite element model based on iterated weighted least squares fits to data and prior constraints. Data include 773 fault traces, 106 fault offset rates, 510 geodetic velocities, 2566 principal stress azimuths, and velocity boundary conditions representing the rigid parts of the Eurasia, Africa, and Anatolia plates. Model predictions include long-term velocities, fault slip rates, and distributed permanent strain rates between faults. One model assumes that geodetic velocities measured adjacent to the Aegean Trench reflect a temporarily locked subduction zone; in this case, longterm subduction velocity averages 45 mm/yr and rapid crustal extension is predicted in the southern Aegean Sea. Another model assumes steady creeping subduction; in this case, subduction velocity averages only 29 mm/yr, and the eastern Aegean Seafloor is predicted to be more nearly rigid. Long-term seismicity maps are computed for each model on the basis of the SHIFT hypotheses and previous global calibrations of plate boundary earthquake production. Retrospective comparisons to seismic catalogs are encouraging: map patterns, spatial distribution functions, and total earthquake counts are all comparable. While neither model accurately predicts earthquake rates at all magnitudes, the creeping subduction model is more accurate for strong m6+ events, which dominate the seismic hazard. Citation: Howe, T. M., and P. Bird (2010), Exploratory models of long-term crustal flow and resulting seismicity across the Alpine-Aegean orogen, Tectonics, 29, TC4023,

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