Tephra (volcanic ash) layers are now an invaluable tool in palaeoenvironmental studies, as well a record of volcanic activity. The data produced by such research can be difficult to handle and disseminate. Tephrabase is a database of tephra layers found in Iceland, north-west and northern Europe, Russia and central Mexico. Details on the location, name, age and geochemistry of tephra layers are stored in the database, as well as information about relevant volcanoes and volcanic systems. A comprehensive reference database is also included. A new Laacher See supplementary data collection has been added.
Tephrabase has been redesigned. I hope that this makes it easier to get at the data you want to find. This is on an ongoing process and new features, including the automatic creation of tephrostratigraphic profiles have just been added and calculations of sediment accumulation rates for Iceland locations will be added shortly.
The data stored in Tephrabase can be broadly divided into five main categories. As Tephrabase develops these will change and it is hoped that connections can also be made to other online systems.
The visualisation of tephra data in Tephrabase is being updated. As well as the maps of tephra sites, we have added a new section which will develop over the next few months. The first new tools generate tephrostratigraphic profiles from selected sites and also graph sediment accumulation rates (SeAR) from select probiles. We intend to add further tools which will map sediment and tephra thickness. [19/05/2015]
The Vedde Tephra was first described in Norway in 1984 and data from the original paper is now available on Tephrabase. For more details see Mangerud, J., Lie, S.E., Furnes, H., Kristiansen, I.L., and Lomo, L. (1984) A Younger Dryas ash bed in western Norway and its possible correlations with tephra in cores from the Norwegian Sea and the North Atlantic. Quaternary Research 21, 85-104. [27/02/2015]
Data on the Dimna Ash and Vedde Ash from the site at Dimnamyra, Dimnøya, Norway, including 60 Geochemical analyses, have been added to Tephrabase. Koren, J.H., Svendsen, J.I., Mangerud, J. and Furnes, H. (2008) The Dimna Ash - A 12.8 C-14 ka-old volcanic ash in Western Norway. Quaternary Science Reviews 27, 85-94. [27/02/2015]
The tephra layers found at Dalican Water (Shetland) have been added to Tephrabase. Further details on these tephra layers can be found in Bennett, K.D., Boreham, S., Sharp, M.J., and Switsur, V.R. (1992) Holocene history of environment, vegetation and human settlement on Catta Ness, Lunnasting, Shetland. Journal of Ecology 80, 241-273. [20/02/2015]
Data on the Saksunarvatn Tephra found at Crudale Meadow and Quoloo Meadow in Orkney can now be found in Tephrabase. Further details from Bunting, M.J. (1994) Vegetation history of Orkney, Scotland; pollen records from two small basins in west Mainland. New Phytologist 128, 771-792. [20/02/2015]
The original geochemical data on the Saksunarvatn Tephra from the Faroe Islands, is now available in Tephrabase. Further details can be found in Mangerud, J., Furnes, H., and Johansen, J. (1986) A 9,000 year old ash bed on the Faroe Islands. Quaternary Research 26, 262-265. [27/02/2015]
In order to help people donate data to Tephrabase, I have created a Word file (form) or PDF file which contain details about the data required. Please download either of the files and either fill in the form or use them to help you include all the information required. Any comments or questions welcome. Please email any data to me, firstname.lastname@example.org. I intend to create a more flexible online system in the future.