Tephra without Borders: Far-Reaching Clues into Past Explosive Eruptions

Abstract

This review is intended to highlight recent exciting advances in the study of distal (>100 km from the source) tephra and cryptotephra deposits and their potential application for volcanology. Geochemical correlations of tephra between proximal and distal locations have extended the geographical distribution of tephra over tens of millions square kilometers. Such correlations embark on the potential to reappraise volume and magnitude estimates of known eruptions. Cryptotephra investigations in marine, lake, and ice-core records also give rise to continuous chronicles of large explosive eruptions many of which were hitherto unknown. Tephra preservation within distal ice sheets and varved lake sediments permit precise dating of parent eruptions and provide new insight into the frequency of eruptions. Recent advances in analytical methods permit an examination of magmatic processes and the evolution of the whole volcanic belts at distances of hundreds and thousands of kilometers from source. Distal tephrochronology has much to offer volcanology and has the potential to significantly contribute to our understanding of sizes, recurrence intervals and geochemical make-up of the large explosive eruptions.

Tephra isochrons and chronologies of colonisation

“…Improving the known geographical extent of 9 th and 10 th century tephras would also help, as this would improve the number of isochrons available at specific locations. Use of either poorly defined layers (Dugmore and Newton, 2012) or cryptotephras (Dugmore et al, 1991) could achieve this -but across much of Iceland the latter would require methodological innovations to isolate low concentrations of very fine-grained tephras within sedimentologically-similar volcanically-derived andosols (Davies, 2015;Ponomareva et al, 2015).…”

Miocene to Holocene Marine Tephrostratigraphy Offshore Northern Central America and Southern Mexico: Pulsed Activity of Known Volcanic Complexes

“…Geochemical fingerprinting of glass shards has been proved to be a reliable tool for tephra correlations (e.g., Kutterolf, Freundt, Peréz, et al, ; Kutterolf et al, ; Ponomareva et al, , ; Lowe, ; Schindlbeck, Kutterolf, Freundt, Alvarado, et al, ). Correlations of ash beds to terrestrial deposits as well as between different marine sites are based on major and trace element concentrations and ratios (Kutterolf, Freundt, Peréz, et al, ; Kutterolf et al, , ; Neugebauer et al, ; Schindlbeck et al, ; Schindlbeck, Kutterolf, Freundt, Alvarado, et al, ; Schindlbeck et al, ; Wulf et al, ) as well as the relative stratigraphic positions and age constraints.…”

“…Wide areal distribution across sedimentary facies boundaries, near‐instantaneous emplacement, unambiguous chemical compositions, and the presence of minerals suitable for radio‐isotopic dating make the deposits of volcanic eruptions to excellent stratigraphic marker beds in terrestrial and marine sediments. Furthermore, they provide constraints on the temporal evolution of both the volcanic source region and the ash‐containing sediment facies (e.g., Kutterolf, Freundt, Peréz, et al, ; Kutterolf, Freundt, & Peréz, ; Kutterolf, Freundt, Schacht, et al, ; Kutterolf, Liebetrau, et al, ; Kutterolf et al ; Ponomareva et al, , , ; Schindlbeck, Kutterolf, Freundt, Alvarado, et al, ; Schindlbeck, Kutterolf, Freundt, Andrews, et al, ; Schindlbeck, Kutterolf, Freundt, Straub, et al, ).…”

Crossing new frontiers: extending tephrochronology as a global geoscientific research tool

“…Secondly, the geographical frontiers of tephrochronology are constantly being extended, in part by modern, systematic cryptotephra studies. Such studies are continually highlighting the revelation that tephras can be traced over much larger areas than previously demonstrated, elevating tephrochronology from a local‐ or regional‐scale to a hemispheric‐scale tool (Jensen et al ., 2014; Davies, 2015; Ponomareva et al, 2015). Thirdly, the ever increasing number of research studies using tephrochronology, the variety of differing applications, and the new studies in this special issue allow us to cross new frontiers in knowledge and understanding.…”