Measuring radiation in the environment following the Fukushima nuclear disaster, Japan

A group of scientists and technical staff from Toshiba Company, including Dr Hirokazu Kanai, undertook field trials at the station using a newly-developed, portable, two-dimensional gamma-ray visualization system known as a “Gamma Camera”

Polynesian settlement of New Zealand and the impacts of volcanism on early Maori society: An update

Presents an overview of the timing of Polynesian settlement in New Zealand, discussing the application of tephrochronology and rat and avian bone dating to the problem. The impacts of volcanism on early Maori society are examined, including the catastrophic impacts of the Tarawera eruption of 1886

Quaternary volcanism, tephras, and tephra-derived soils in New Zealand: an introductory review

This two-part article comprises brief introductions to (1) volcanism and its products in general and to the broad pattern of Quaternary volcanism and tephrostratigraphy in North Island, and (2) the ensuing tephra-derived soils of North Island. Part 1 derives mainly from Smith et al. (2006), Leonard et al. (2007), and Lowe (2008a). Other useful reviews include those of Neall (2001), Graham (2008: Chapter 7), Wilson et al. (2009), and Cole et al. (2010). Recent reviews on tephras include Shane (2000), Alloway et al. (2007), Lowe (2008b, 2011), and Lowe et al. (2008a, 2008b). A history of tephra studies in New Zealand was reported by Lowe (1990). Part 2 describes the distribution and character of the main tephra-derived soils, these being Entisols and Andisols (mostly Vitrands and Udands) and Ultisols (Lowe and Palmer, 2005). Books on these and other soils in New Zealand include NZ Soil Bureau (1968), Gibbs (1980), McLaren and Cameron (1996), Cornforth (1998), and Molloy and Christie (1998). An excellent overview is the web-based article by Hewitt (2008), and encyclopaedic reviews by Neall (2006) and McDaniel et al. (2011) include New Zealand examples. Tonkin (2007a, 2007b, 2007c) provided a history of soil survey and soil conservation activities in New Zealand. A quantitatively-based classification of New Zealand‟s terrestrial environments was published by Leathwick et al. (2003)

Stratigraphy, age, composition, and correlation of late Quaternary tephras interbedded with organic sediments in Waikato lakes, North Island, New Zealand

Cores from 14 peaty lakes in the central Waikato region, northern North Island, contain a sequence of 41 well-preserved, mainly macroscopic, occasionally bedded, ash and lapilli layers ranging in thickness from c. 2 to 110 mm and interbedded with fine-grained organic lake sediment. The layers, whose field and compositional properties are described in detail, are distal airfall tephras that were erupted between c. 17000 and c. 1800 ¹⁴C years ago from six rhyolitic and andesitic volcanic centres located c. 70-200 km from the Waikato sites: Taupo (5 tephras), Okataina (7), Maroa (1) (rhyolitic); Mayor Island (2) (peralkaline); Tongariro (11), and Egmont (15) (andesitic)

INTREPID Tephra-II: - 1307F

The INTREPID Tephra project, “Enhancing tephrochronology as a global research tool through improved fingerprinting and correlation techniques and uncertainty modelling”, was an overarching project of the international community of tephrochronologists of the International Focus Group on Tephrochronology and Volcanism (INTAV), which in turn lies under the auspices of INQUA’s Stratigraphy and Chronology Commission (SACCOM). INTREPID’s main aim has been to advance our understanding and efficacy in fingerprinting, correlating, and dating techniques, and to evaluate and quantify uncertainty in tephrochronology, and thus enhance our ability to provide the best possible linking, dating and synchronising tool for a wide range of Quaternary research projects around the world. A second aim has been to re-build the global capability of tephrochronology for future research endeavours through mentoring and encouragement of emerging researchers in the discipline

Connecting with tephras: principles, functioning, and applications of tephrochronology in Quaternary science

Tephrochronology is a unique method for linking and dating geological, palaeoecological, palaeoclimatic, or archaeological sequences or events. The method relies firstly on stratigraphy and the law of superposition, which apply in any study that connects or correlates deposits from one place to another. Secondly, it relies on characterising and hence identifying or ‘fingerprinting’ tephra layers using either physical properties evident in the field or those obtained from laboratory analysis, including mineralogical examination by optical microscopy or geochemical analysis of glass shards or crystals (e.g., Fe-Ti oxides, ferromagnesian minerals) using the electron microprobe and other tools. Thirdly, the method is enhanced when a numerical age is obtained for a tephra layer by (1) radiometric methods such as radiocarbon, fission-track, U-series, or Ar/Ar dating, (2) incremental dating methods including dendrochronology or varved sediments or layering in ice cores, or (3) age-equivalent methods such as palaeomagnetism or correlation with marine oxygen isotope stages or palynostratigraphy. Once known, that age can be transferred from one site to the next using stratigraphic methods and by matching compositional characteristics, i.e., comparing ‘fingerprints’ from each layer. Used this way, tephrochronology is an age-equivalent dating method

Project 0907: INTREPID – Enhancing tephrochronology as a global research tool through improved fingerprinting and correlation techniques and uncertainty modelling

In May, 2010, the inter-congress meeting of the INQUA International focus group on tephrochronology and volcanism (INTAV) was held in Kirishima City, southern Kyushu, Japan. INTAV was formed in 2007 at the International Union for Quaternary Research (INQUA) congress held in Cairns. It replaced SCOTAV (Sub-commission on tephrochronology and volcanism), COT (Commission on tephrochronology), and earlier tephrarelated research groups dating back to the 1960s. Previous meetings of the group in the past two decades were held in the Yukon Territory, Canada (2005), France (1998), New Zealand (1994), and USA (1990). The venue for the 2010 meeting was the main hall of the Kokobu Civic Centre in Kirishima City, which was very generously provided free of charge by the Kirishima authorities in return partly for the delivery of two public lectures, one by David Lowe (“Connecting with our past: using tephras and archaeology to date the Polynesian settlement of Aotearoa/New Zealand”) and the other by Hiroshi Machida (“Widespread tephras originating from Kagoshima occurring in northeast Asia and adjacent seas”), on Sunday 9 May. Participants were treated to a personal welcome by the Mayor of Kirishima City, Shuji Maeda, followed by what appeared to be a very special (and delicious) banquet. However, this spread turned out to be standard lunch and dinner fare provided by the centre’s cafeteria and was enjoyed by participants throughout the meeting

Stop 2 Kainui silt loam and Naike clay, Gordonton Rd

At this stop are several remarkable features both stratigraphic and pedological, and a “two-storied” soil, the Kainui silt loam alongside (in just a few places) the Naike clay. Both soils are Ultisols. The sequence of tephra beds and buried soil horizons spanning about 1 million years was exposed in 2007 by road works

Application of impulse radar to continuous profiling of tephra-bearing lake sediments and peats: an initial evaluation

Subsurface interface radar SIR, or impulse radar, uses electromagnetic pulses for continuous stratigraphic profiling. It has been applied to lake sediments (dy-gyttja) and peat deposits containing a sequence of thin, late Quaternary, ash-grade tephras at Lake Maratoto, North Island, New Zealand. The SIR system is very rapid, precise, and reasonably accurate compared with conventional coring and probing methods, but still requires good stratigraphic control for reliable interpretation. Radar penetration depths of up to 10 m were attained. Interfaces between lake bottom and lake sediments and underlying volcanogenic materials of varying lithologies could be readily discerned, as could many of the tephra layers preserved within the lake sediments. Peat depths and positions of stumps or logs on the surface of the subpeat materials could also be determined. Given adequate calibration by drilling, the SIR system appears useful for various shallow subsurface exploration studies, particularly those involving tephrostratig raphy and paleoenvironmental reconstructions from limnic and peat deposits, and in projects on buried wood

Marine tephrochronology: a personal perspective

This special volume on marine tephrochronology is remarkable, and timely, because it marks a concerted step towards what might be informally termed ‘phase 3’ of a revolution in Quaternary geosciences that began around 40 years ago. The 10 articles collectively represent a re-focussed examination of tephras and cryptotephras preserved in ocean sediments at various locations and the authors describe their significance for a range of subdisciplines. Eight articles provide a new understanding of the origin, distribution and ages of various tephra and cryptotephra deposits and their stratigraphic inter-relationships; how the terrestrial ages of the tephra/crypotephra deposits relate to those of enclosing sediments and inform the ongoing development of the marine radiocarbon time-scale; mechanisms for the emplacement, remobilization or bioturbation of the tephras or cryptotephras; and volcanic eruption history. Two further articles document the characterization of tephra-derived glass shards using microbeam techniques to analyse 30–40 elements from individual shards as small as 10 µm in diameter. The collection thus provides snapshots of many aspects of the latest developments and directions in tephra studies – volcanology, primary and secondary dispersal, stratigraphy, single-grain characterization, chronology – through the medium of marine sediments. My personal perspective reflects briefly on how this point was reached and identifies a few of the important milestones on the way from ‘phase 1’ to ‘phase 3’. I am privileged to write it. Marine science revolution As an undergraduate in the early-mid 1970s, I recall my first real ‘awakening’ regarding the dynamic nature of science, and of Quaternary geoscience in particular, when told about deep-sea core V28-238 from the equatorial Pacific Ocean (Shackleton & Opdyke 1973; >2650 citations, Google Scholar). Analogous to the opening notes of Beethoven's 5th Symphony, perhaps the most famous quartet of notes in history, the alpha-numerical assemblage ‘V28-