Several cryptotephra layers that originate from Icelandic volcanic eruptions with a volcanic explosivity index (VEI) of ≤ 4 and tephra volumes of < 1 km³ have previously been identified in Northern Europe, albeit within a restricted geographical area. One of these is the Hekla 1947 tephra that formed a visible fall‐out in southern Finland. We searched for the Hekla 1947 tephra from peat archives within the previously inferred fall‐out zone but found no evidence of its presence. Instead, we report the first identification of Hekla 1845 and Hekla 1510 cryptotephra layers outside of Iceland, the Faroe Islands, Ireland and the UK. Additionally, Hekla 1158 tephra was found in Finland for the first time. Our results confirm that Icelandic eruptions of moderate size can form cryptotephra deposits that are extensive enough to be used in inter‐regional correlations of environmental archives and carry a great potential for refining regional tephrochronological frameworks. Our results also reveal that Icelandic tephra has been dispersed into Finnish airspace at least seven times during the past millennium and in addition to a direct eastward route the ash clouds can travel either via a northerly or a southerly transport pathway.

中文翻译：

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芬兰的Hekla 1947、1845、1510和1158年的特非拉：从中度爆发中追踪特非拉的挑战

源自冰岛火山喷发的几个隐火山岩层，火山爆发指数（VEI）≤4，且火山灰质体积<1 km ³尽管在有限的地理区域内，但之前在北欧已被确定。其中之一就是Hekla 1947特非拉，它在芬兰南部形成了明显的沉降物。我们从先前推断的沉降带内的泥炭档案中搜索了Hekla 1947特非拉，但没有发现它存在的证据。相反，我们报告了冰岛，法罗群岛，爱尔兰和英国以外的Hekla 1845和Hekla 1510隐密码的首次鉴定。此外，首次在芬兰发现了Hekla 1158特非拉。我们的结果证实，冰岛中等规模的火山喷发可以形成隐隐孢子矿床，其规模足够大，可用于环境档案的区域间关联，并具有完善区域年代年代学框架的巨大潜力。