Tephra fall at Tungurahua Volcano (Ecuador) – 1999-2014: An Example of Tephra Accumulation from a Long-lasting Eruptive Cycle

Tungurahua volcano awoke in 1999 after 75 years of quiescence, and its activity continues at the time of writing (2015). After fifteen years of eruptions, roughly 0.13 km³ of tephra have been released and deposited mainly to the west and southwest of the volcano. In order to describe the activity an...

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Bibliographic Details
Authors: Bustillos A., Jorge, Romero, Jorge E., Troncoso, Liliana, Guevara C., Alicia
Format: article
Status:Published version
Publication Date:2015
Country:México
Institution:UNIVERSIDAD NACIONAL AUTÓNOMA DE MÉXICO
Repository:Geofísica Internacional
Language:Spanish
English
OAI Identifier:oai:revistagi.geofisica.unam.mx:article/57
Online Access:http://revistagi.geofisica.unam.mx/index.php/RGI/article/view/57
Access Level:Open access
Keyword:Tefra
erupciones explosivas
estilo eruptivo
Tungurahua
tasa de descarga
volumen emitido
Tephra
explosive eruptions
eruption style
discharge rate
eruptive volume
Description
Summary:Tungurahua volcano awoke in 1999 after 75 years of quiescence, and its activity continues at the time of writing (2015). After fifteen years of eruptions, roughly 0.13 km³ of tephra have been released and deposited mainly to the west and southwest of the volcano. In order to describe the activity and understand the implications associated to its tephra emissions, we review the: 1) their distribution, 2) quantification of ejecta, 3) their components and 4) eruption dynamics. Most of the eruptions have consisted of short-lived explosions, Strombolian eruptions, hydro-volcanic interactions triggering Vulcanian eruptions, one Subplinian event and transitional style phases, which is supported by analysis of tephra components. Major tephra fallouts occurred in 2001, 2006, and 2014. The rate of tephra discharge increased almost 2.1 times from the pre-2006 period to the post-2006 period. Tungurahua poses a continuing geological hazard across the adjacent regions, but also it is a natural laboratory for studying long-lasting eruptions and their effect.