Reconstructing the tephra dispersal pattern from the Bronze Age eruption of Santorini using an advection-diffusion model
Reconstructing the tephra dispersal pattern from the Bronze Age eruption of Santorini using an advection-diffusion model
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DOI：
10.1007/s00445-012-0609-x
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发表时间：
2012-08-01
影响因子：
3.5
通讯作者：
Watson, I. M.
中科院分区：
文献类型：
--
作者：
Johnston, E. N.;Phillips, J. C.;Watson, I. M.
对流扩散模型TEPHRA 2已被用于结合下坡单纯形法（DSM）和一次一个（OAT）反演方法重建的喷发条件和季节性一致的存款模式从青铜时代（“米诺斯”）爆发的圣托里尼。我们调查了三个数据集代表不同的沉积环境（近端陆地，远端陆地和深海核心），以确定源条件，如羽高度，爆发的质量和粒度和重建火山碎屑瀑布存款从普林尼，共熔结凝灰岩和组合喷发阶段。DSM和OAT方法的结果彼此吻合得很好的喷发质量，羽流高度和粒度分布。这两种方法都能够成功地重建普林尼存款，但估计条件，创造了共同熔结凝灰岩和深海核心数据集是不太成功的。减少的协议是由于低数量（6至28存款点）和质量（不一致的存款深度的地方彼此相邻）的数据集，和不同的动态之间的co-ignimbrite和普林尼柱，前者没有很好地代表在模型中。考古学和火山学学科之间的不同采样方法以及自青铜时代以来作用于火山碎屑沉积物的沉积后过程可以解释这些计算和观察到的沉积物之间的差异。通过使用冬季、春季、夏季和秋季的季节性风廓线来研究米诺斯火山喷发的季节性。我们发现，青铜时代的圣托里尼火山喷发很可能在春季和夏季的几个月内，与一个主要的分散轴对准东。克里特岛会收到很少的火山灰，火山爆发不会对岛上居民的生活造成太大的干扰。
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, co-ignimbrite 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 co-ignimbrite 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.