Tephrochronology

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TephrochronologySEA_webbaner 1a_030519.pngTephrochronology is a technique that uses discrete layers of tephra (i.e. volcanic ash) to create a chronological framework (Lowe 2011) useful to reconstruct the volcanic history of a given area. Its applications are numerous and there is great potential for expansion in Southeast Asia given the exceptional high density of volcanoes in this part of the world. The goal of this workshop is thus to review the current knowledge about tephrochronologic markers in the region — their composition and ages, to share findings and best practices, and to instigate region-wide collaboration.

The identification and correlation of tephra layers enables reconstruction of the number, timing and magnitude of eruptions that affected a given location. Improving our knowledge of volcanic eruption histories in Southeast Asia is important for a number of factors, the most obvious of which is regional hazards. Southeast Asia hosts ~750 volcanoes (70 of which have erupted in the past century) and is home to a population of ~600 Million. In Indonesia, for example, ~30% of the population lives within 30 km from a Holocene volcano. Another important factor is that Southeast Asian volcanoes are dominantly located close to the equator. Indeed, large volcanic eruptions that occur in equatorial to tropical regions and send ash into the stratosphere have particularly global impacts on climate because the ash and aerosols released propagate into both the northern and southern hemispheres.

143 volcanoes in Southeast Asia have been classified as Large Calderas (41) and Well-Plugged Stratocones (102) by Whelley & al (2015) and thus have or are likely to have produced large explosive eruptions with a Volcano Explosivity Index (VEI) of 5-8. Only 26 of such eruptions have known ages, spanning from 1.2 Ma to 1991 AD. Fewer have geochemical data that can be used for tephrostratigraphic correlations. Consequently, there is a knowledge gap that can be filled through field studies of these numerous volcanoes in combination with studies of marine, lacustrine, and other on-land sedimentary records.

Marine and lake sediments are fantastic archives of meteorological and geological processes (e.g. floods, landslides, volcanic eruptions, earthquakes) and environmental change (e.g. climate and land-use changes). For example, long term hydrological variations are recorded as changes in sedimentology, geochemistry and biological proxies in lacustrine and marine settings. Thus sediments from lakes and oceans provide high resolution palaeoenvironmental data for variations and interactions of the monsoons, El Nino Southern Oscillation, Indian Ocean Dipole, floods and droughts, and human activities. The identification and correlation of tephra layers in these archives enables linking, synchronizing and dating geological or environmental events that impact the local and regional ecology, human and climatic history. Filling the knowledge gap concerning volcanic eruption histories would thus contribute to further developing additional tephrochronologic markers that could help synchronize records over a larger spatial extent, at a greater temporal resolution, and over a greater period of time.

This workshop is an exciting opportunity to share knowledge and findings in order to start filling the identified knowledge gaps, and better define regional marker beds. It is also the opportunity to identify specific research targets that could be undertaken in collaboration, and action items to be revisited during a subsequent workshop. Lastly, it is a chance to train the new generation of Earth scientists and promote the use of tephrostratigraphy in this part of the world.


Please register online before 28 July 2019Registration closed

Admission is free. Seats are limited, so hurry! 

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Important Dates

Financial Support (Students)

​Application Closes

​21 Jun 2019 - Closed

Poster Title

Poster Title Submission Closes

21 Jun 2019  Closed

Acceptance Notification

28 Jun 2019

Registration

Online Registration Closes

28 Jul 2019  Closed

Workshop Period

7 to 8 Aug 2019

 

 

Jointly organized by

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Asian School of the Environment, NTU

Institute of Advanced Studies, NTU

 

Supporting organisation

 

Earth Observatory of Singapore

 

Workshop Chair

Assistant Professor Caroline Bouvet de Maisonneuve

National Research Foundation (NRF) Fellow

Nanyang Assistant Professor (NRF), Asian School of the Environment

Email: carolinebouvet@ntu.edu.sg  

 

Contact

Secretariat: Ms Nur Fairuz Binte Razali

Email: nfairuz@ntu.edu.sg

Asian School of the Environment

Nanyang Technological University

50 Nanyang Avenue, Block N2-01C-63

Singapore 639798

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