The Late Bronze Age 'Minoan' eruption of Santorini, Greece occurred from within an existing caldera. Low-temperature pyroclastic flow emplacement on shallow slopes outside the caldera can only be consistent with the caldera being filled with eruption products that are not preserved. Field observations and seismic reflection surveys suggest that this missing material has been downfaulted. The volume of the caldera infill is estimated as 18-26 km 3 dense rock equivalent (DRE), increasing the total of the Minoan eruption deposits to 78-86 km 3 DRE and making it the largest known Holocene eruption. This study highlights a general mechanism whereby caldera eruption volumes could be significantly underestimated.
We propose a new volcanological interpretation of Santorini’s intracaldera fill deposits as revealed by seismic reflection profiles. This interpretation, along with supplementary gravity and geophysical studies, reveals three distinct volcaniclastic units (1–3). From top to bottom these units are attributed to (1) modern infilling sediment, (2) shallow marine phreatomagmatic volcanism associated with the relatively recent formation of the Kameni Islands, and (3) downfaulted ‘Minoan’ pyroclastic deposits, which formed during caldera collapse towards the end of the Bronze Age eruption. Estimates of the volumes of the seismic units and Kameni Islands yield a dense rock equivalent magma volume of 4.85 ± 0.7 km 3 . The average rate of volcanism over the past c . 3641 years is estimated at 1.3 ×10 −3 km 3 a −1 , and is similar to the rate since the AD 1707 eruption of 1.2 ×10 −3 km 3 a −1 based on historical lava volume estimates.
The advection–diffusion model TEPHRA2 has been used in conjunction with the downhill simplex method (DSM) and one-at-a-time (OAT) inversion methods to reconstruct the eruption conditions and seasonality consistent with the deposit patterns from the Bronze Age (‘Minoan’) eruption of Santorini. We investigated three datasets representing different depositional environments (proximal terrestrial, distal terrestrial and deep-sea core), in order to determine source conditions such as plume height, erupted mass and grain-size and recreate the tephra fall deposit from the Plinian, coignimbrite and combined eruptive phases. The results of the DSM and OAT method agreed adequately well with each other for erupted mass, plume height and grain-size distribution. Both approaches were able to successfully recreate the Plinian deposit but estimating conditions that created the coignimbrite and deep-sea core dataset were less successful. The reduced agreement is the result of the low quantity (6 to 28 deposit points) and quality (inconsistent deposit depths at localities adjacent to each other) of the datasets, and the different dynamics between co-ignimbrite and Plinian columns, with the former not well represented in the model. Different sampling methods between archaeological and volcanological disciplines and post-depositional processes which have acted on the tephra deposits since the Bronze Age can explain the discrepancy between these computed and observed deposits. The seasonality of the Minoan eruption was investigated by using seasonal wind profiles for winter, spring, summer and autumn. We find that the Bronze Age eruption of Santorini is likely to have during the spring and summer months with a main dispersal axis aligned East. Crete would have received very little ash fall, and the eruption would not have caused much disruption to the life of the inhabitants of the island
Right ventricular failure (RVF) is an underestimated problem in intensive care. This review explores the physiology and pathophysiology of right ventricular function and the pulmonary circulation. When RVF is secondary to an acute increase in afterload, the picture is one of acute cor pulmonale, as occurs in the context of acute respiratory distress syndrome, pulmonary embolism and sepsis. RVF can also be caused by right myocardial dysfunction. Pulmonary arterial catheterization and echocardiography are discussed in terms of their roles in diagnosis and treatment. Treatments include options to reduce right ventricular afterload, specific pulmonary vasodilators and inotropes.
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