Volcanism - climate interaction: A test case from the Azores archipelago (VolClimA)

对冰岛和其他冰川覆盖地区的研究表明，在最后一次冰期之后，火山活动显著增加，这可能是由于冰川退缩期间岩石圈的卸载。此外，海洋火山灰记录表明，在第四纪冰川开始时，与弧有关的爆发性火山灰层的频率明显增加。虽然将气候变化与火山活动联系起来的物理过程是目前讨论的主题，但这一专题与我们目前的情况特别相关，因为人为造成的冰川消退可能导致火山活动和危险增加。人们已经认识到，火山活动的记录，长到足以覆盖许多冰川周期，与全球气候记录（米兰科维奇周期）共享相同的周期性。观测到的火山喷发频率的周期性波动与轨道气候变化周期的巧合是目前最有力的证据，表明火山活动可能是由轨道参数本身（例如，固体地球潮汐）或其全球气候效应（例如，全球规模的质量再分布在（去）冰川和冰川大陆侵蚀）。虽然基本上所有的研究都认为全球气候变化在某种程度上影响了火山活动，通常导致冰川消退期间火山活动的增加，但关于周期性和时间的结果在细节上存在显着差异。到目前为止，这阻碍了统一理论的发展，以解释潜在的物理机制。为了解决这个问题，有必要调查相关数量的长期和精确的年代地层火山灰记录从不同的大地构造环境（弧和海洋岛屿/热点），和纬度，并研究这些记录的时间和空间变化的系统变化。迄今为止，所有调查火山活动与气候相互作用的长期火山时间序列的研究都使用了来自火山弧或全球汇编的海洋火山灰记录，但仍然缺少对海洋岛屿环境的详细长期研究。在拟议的项目中，我的目标是生产，地球化学分析（主要和微量元素，测年技术），到目前为止（14 C，Ar/Ar，氧同位素地层学），并首次统计评估一个长期的记录，涵盖了一个海洋岛屿设置（热点），超越了最后一次冰消期，我的目标是使用亚速尔群岛作为一个测试案例。我将利用“流星号”考察船两次巡航（M141和M186）期间获得的特殊海洋沉积物记录，并结合从群岛陆上部分采集的样本，建立最完整的原生和次生火山事件记录。

The recognition of global climate changes as a control on volcanism came from studies on Iceland, and other glacier-covered regions, which demonstrated a significant increase in volcanic activity after the last glaciation, probably facilitated by unloading of the lithosphere during glacier retreat. Moreover, marine tephra records show a clear increase in frequency of tephra layers from arc- related explosive eruptions at the onset of the Quaternary glaciations. While the physical processes that link climate changes to volcanism are subject of ongoing discussions, this topic is especially relevant for our present-day situation because anthropogenically enforced deglaciation may lead to increased volcanic activity and hazards. It has been recognized that records of volcanic activity, long enough to cover many glacial cycles, share the same periodicities with the global climate record (Milankovitch periods). The observed coincidences of periodic fluctuations in the volcanic eruption frequency with periods of orbitally paced climate changes are presently the strongest evidence that volcanism may be forced by either the orbital parameters themselves (e.g., solid Earth tides) or by their global climatic effects (e.g., global-scale mass redistributions during (de)glaciation and glacial continental erosion). While basically all studies agree that global climate changes somehow affect volcanism, typically leading to increased volcanism during deglaciation periods, the results regarding periodicities and timing differ significantly in detail. This has so far hindered the development of a unified theory to explain the underlying physical mechanisms. To tackle this problem, it is necessary to investigate a relevant number of long and precise chronostratigraphic tephra records from different geotectonic settings (arc and ocean islands/hotspots), and latitudes and to study these records regarding systematic changes of temporal and spatial variations. All studies that investigated long-term volcanic time series regarding volcanism-climate interaction so far used marine tephra records either from volcanic-arcs or global compilations, but a detailed long-term study of an ocean island setting is still missing. In the proposed project I aim to produce, to geochemically analyze (major and trace elements, dating techniques), to date (14C, Ar/Ar, oxygen isotope stratigraphy), and to statistically evaluate for the first time a long-term record covering of an oceanic island setting (hotspot) that goes beyond the last deglaciation and I aim to use the Azores as a testcase. I will use the exceptional marine sediment records obtained during two RV Meteor cruises (M141 and M186) in combination with samples from the subaerial part of the islands to establish a most complete record of primary and secondary volcanic events.