Search

Distal tephra from the major Somma-Vesuvius Avellino (AV) eruption is widespread in the coastal basins of Southern Lazio (Central Italy). Dated to 1995 ± 10 cal yr BC in 2011, later on doubts arose about the reliability of this frequently cited age. This led to a major effort to date AV tephra holding sections, based on a thorough methodological approach. Various aspects were studied to identify sections yielding reliable 14C ages, including bioturbation, inbuilt age, and variable sediment accumulation rate. Lowered rates upon deposition of tephra, particularly in anoxic marshy environments and attributed to toxic F contents, showed up as sharp increases in pollen density. The ‘sampling error’ was quantified for specific sedimentary environments and derived from coring data and published data on accumulation rates for similar Central Mediterranean sites. Next, two Bayesian analyses were performed, a traditional using the full set of samples and a novel, based on samples that were deemed as suitable (no bioturbation, inbuilt age, etc.) and of which the age was corrected for the sampling error. The age obtained by the novel analysis had the smallest range (1909-1868 cal yr BC), differs about a century, and is virtually identical to the ages published by Passariello et al. (2009) and Alessandri (2019). The earlier found age (2011) is ascribed to a statistical coincidence. The results solve a long debate on the age of the AV eruption, which is the youngest of the three major eruptions in the Central Mediterranean Bronze Age. Ages of the other two, the Agnano Mt Spina (Phlegrean) and FL eruption (Etna), are still uncertain and disputed. This study illustrates the need for a thorough approach in 14C dating tephra holding sediment archives in the Central Mediterranean, and employed a methodology that can be applied in such approach. Attention is called for potentially toxic fluorine concentrations in Campanian tephra, which may have had a serious impact on the contemporary environment and induced chronological hiatuses, but hitherto were not reported for the early tephra.

We, the members of the Division for Chronological Research at the Institute for Space-Earth Environmental Research at Nagoya University, held a regional contribution program for the higher grade elementary school students on August 3–4, 2017: “Investigation of natural and environmental history in the Tokai region”. Twenty-seven students observed natural samples to experience earth and archaeological sciences. The first day began with lectures on tephra chronology and dendrochronology. After the lecture, the students took part in several hands-on experiments by using tephra and annual tree rings. On the second day they travelled to Shizuoka by bus and visited the Museum of Natural and Environmental History, Shizuoka to study natural and environmental history in the Tokai region. Later in the day they went to Miho no Matsubara to observe the states of coastal erosion and pine wilt disease. Finally, they went to Nihondaira to study about a movement of the earth’s crust. The program ended a success. The post-program questionnaire shows that the participants enjoyed the program and learned many new things., 宇宙地球環境研究所年代測定研究部は，静岡県ふじのくに地球環境史ミュージアムの山田和芳教授，菅原大助准教授，静岡大学理学部の北村晃寿教授と協力し，平成29年8月3日（木）と4日（金）の2日間にわたり，小学高学年生27名を対象とした夏休み体験学習「東海の地球環境史を学ぼう」を行いました．教室での講義だけでは得られ難い実体験の機会は，子どもたちの科学への興味や関心をより高めるきっかけになり，本体験学習の目的は十分達成できたと考えられる．

Lateglacial and early-Holocene mean July air temperatures have been reconstructed, using a chironomid-based inference model, from lake-sediment sequences from Abernethy Forest, in the eastern Highlands of Scotland, and Loch Ashik, on the Isle of Skye in north-west Scotland. Chronology for Abernethy Forest was derived from radiocarbon dates of terrestrial plant macrofossils deposited in the lake sediments. Chronology for Loch Ashik was derived from tephra layers of known ages, the first age-depth model of this kind. Chironomid-inferred temperatures peak early in the Lateglacial Interstadial and then gradually decline by about 1 °C to the beginning of the Younger Dryas (YD). At Abernethy Forest, the Lateglacial Interstadial is punctuated by three centennial-scale cold oscillations which appear to be synchronous with the Greenland Interstadial events GI-1d, when temperatures at Abernethy fell by 5.9 °C, GI-1c, when temperatures fell by 2.3 °C, and GI-1b, when temperatures fell by 2.8 °C. At Loch Ashik only the oscillation correlated with GI-1d is clearly defined, when temperatures fell by 3.8 °C. The start of the YD is clearly marked at both sites when temperatures fell by 5.5 °C at Abernethy Forest and 2.8 °C at Loch Ashik. A warming trend is apparent during the late-YD at Abernethy Forest but at Loch Ashik late-YD temperatures became very cold, possibly influenced by its close proximity to the Skye ice-field. The rapidly rising temperatures at the YD – Holocene transition occur about 300 years earlier at both sites than changes in sediment lithology and loss-on-ignition. The temperature trends at both sites are broadly similar, although between-site differences may result from the influence of local factors. Similar climate trends are found at other sites in the northern British Isles. However, the British summer temperature records differ in detail from trends in the oxygen-isotope records from the Greenland ice-cores and from other chironomid-inferred temperature records available from Scandinavia, north-west Europe and central Europe, which suggest important differences in the influence of climatic forcing at regional scales. publishedVersion