Gravity and geodesy of concepción volcano, Nicaragua

José Armando Saballos, Rocco Malservisi, Charles B. Connor, Peter Christopher Lafemina, Paul Wetmore

Research output: Chapter in Book/Report/Conference proceedingChapter

Abstract

Concepción is currently the most active composite volcano in Nicaragua. Ash explosions of small to moderate size (volcano explosivity index 1-2) have occurred on a regular basis. Gravity data collected on and around the volcano between 2007 and 2010 confi rm that a younger cone is built atop an older truncated edifi ce of denser material, predominantly lavas. The bulk density of the volcanic cone is 1764 kg m-3 (with an uncertainty of at least ± 111 kg m-3), derived from gravity data. This estimated bulk density is signifi cantly lower than densities (e.g., 2500 kg m-3) used in previous models of gravitational spreading of this volcano and suggests that the gravitational load of the edifi ce may be much lower than previously thought. The gravity data also revealed the existence of a possible northwest-southeast-oriented normal fault (parallel to the subduction zone). Episodic geodetic data gathered with dualfrequency global positioning system (GPS) instruments at fi ve sites located around the volcano's base show no signifi cant change in baseline length during 8 yr and 2 yr of observations along separate baselines. Structures deformed after the Tierra Blanca Plinian eruption ca. 19 ka, which signifi cantly altered the form and bulk density of the volcano, may be due to the spreading of the volcano, but may also be related to volcano loading, magmatic intrusions and their subsequent evolution, and other volcano-tectonic processes, or a combination of any of these factors. A joint interpretation of our gravity and geodetic GPS data of Concepción suggests that this volcano is not spreading in a continuous fashion; if it is episodically spreading, it is driven by magma intrusion rather than gravity. These results have important implications for volcanic hazards associated with Concepción Volcano. Although during the last 15 yr tephra fallout and volcanic debris fl ows (lahars) have been the pervasive hazards at this volcano, earthquakes from an eventual slip of the fault on the east-northeast side of the volcano (delineated from our gravity measurements) should be considered as another important hazard, which may severely damage the infrastructures in the island, and conceivably trigger a volcano fl ank collapse.

Original languageEnglish (US)
Title of host publicationUnderstanding Open-Vent Volcanism and Related Hazards
EditorsJose Luis Palma, Hugo Delgado Granados, William I. Rose, Nick Varley
PublisherGeological Society of America
Pages77-88
Number of pages12
ISBN (Electronic)9780813724980
DOIs
StatePublished - Jan 1 2013

Publication series

NameSpecial Paper of the Geological Society of America
Volume498
ISSN (Print)0072-1077

Fingerprint

geodesy
volcano
gravity
bulk density
hazard
GPS
plinian eruption
stratovolcano
geodetic datum
tephra
fallout
normal fault
subduction zone
explosion
ash
magma
infrastructure

All Science Journal Classification (ASJC) codes

  • Geology

Cite this

Saballos, J. A., Malservisi, R., Connor, C. B., Lafemina, P. C., & Wetmore, P. (2013). Gravity and geodesy of concepción volcano, Nicaragua. In J. L. Palma, H. D. Granados, W. I. Rose, & N. Varley (Eds.), Understanding Open-Vent Volcanism and Related Hazards (pp. 77-88). (Special Paper of the Geological Society of America; Vol. 498). Geological Society of America. https://doi.org/10.1130/2013.2498(05)
Saballos, José Armando ; Malservisi, Rocco ; Connor, Charles B. ; Lafemina, Peter Christopher ; Wetmore, Paul. / Gravity and geodesy of concepción volcano, Nicaragua. Understanding Open-Vent Volcanism and Related Hazards. editor / Jose Luis Palma ; Hugo Delgado Granados ; William I. Rose ; Nick Varley. Geological Society of America, 2013. pp. 77-88 (Special Paper of the Geological Society of America).
@inbook{e286d3e3fbbe483792d480ba088ce02b,
title = "Gravity and geodesy of concepci{\'o}n volcano, Nicaragua",
abstract = "Concepci{\'o}n is currently the most active composite volcano in Nicaragua. Ash explosions of small to moderate size (volcano explosivity index 1-2) have occurred on a regular basis. Gravity data collected on and around the volcano between 2007 and 2010 confi rm that a younger cone is built atop an older truncated edifi ce of denser material, predominantly lavas. The bulk density of the volcanic cone is 1764 kg m-3 (with an uncertainty of at least ± 111 kg m-3), derived from gravity data. This estimated bulk density is signifi cantly lower than densities (e.g., 2500 kg m-3) used in previous models of gravitational spreading of this volcano and suggests that the gravitational load of the edifi ce may be much lower than previously thought. The gravity data also revealed the existence of a possible northwest-southeast-oriented normal fault (parallel to the subduction zone). Episodic geodetic data gathered with dualfrequency global positioning system (GPS) instruments at fi ve sites located around the volcano's base show no signifi cant change in baseline length during 8 yr and 2 yr of observations along separate baselines. Structures deformed after the Tierra Blanca Plinian eruption ca. 19 ka, which signifi cantly altered the form and bulk density of the volcano, may be due to the spreading of the volcano, but may also be related to volcano loading, magmatic intrusions and their subsequent evolution, and other volcano-tectonic processes, or a combination of any of these factors. A joint interpretation of our gravity and geodetic GPS data of Concepci{\'o}n suggests that this volcano is not spreading in a continuous fashion; if it is episodically spreading, it is driven by magma intrusion rather than gravity. These results have important implications for volcanic hazards associated with Concepci{\'o}n Volcano. Although during the last 15 yr tephra fallout and volcanic debris fl ows (lahars) have been the pervasive hazards at this volcano, earthquakes from an eventual slip of the fault on the east-northeast side of the volcano (delineated from our gravity measurements) should be considered as another important hazard, which may severely damage the infrastructures in the island, and conceivably trigger a volcano fl ank collapse.",
author = "Saballos, {Jos{\'e} Armando} and Rocco Malservisi and Connor, {Charles B.} and Lafemina, {Peter Christopher} and Paul Wetmore",
year = "2013",
month = "1",
day = "1",
doi = "10.1130/2013.2498(05)",
language = "English (US)",
series = "Special Paper of the Geological Society of America",
publisher = "Geological Society of America",
pages = "77--88",
editor = "Palma, {Jose Luis} and Granados, {Hugo Delgado} and Rose, {William I.} and Nick Varley",
booktitle = "Understanding Open-Vent Volcanism and Related Hazards",
address = "United States",

}

Saballos, JA, Malservisi, R, Connor, CB, Lafemina, PC & Wetmore, P 2013, Gravity and geodesy of concepción volcano, Nicaragua. in JL Palma, HD Granados, WI Rose & N Varley (eds), Understanding Open-Vent Volcanism and Related Hazards. Special Paper of the Geological Society of America, vol. 498, Geological Society of America, pp. 77-88. https://doi.org/10.1130/2013.2498(05)

Gravity and geodesy of concepción volcano, Nicaragua. / Saballos, José Armando; Malservisi, Rocco; Connor, Charles B.; Lafemina, Peter Christopher; Wetmore, Paul.

Understanding Open-Vent Volcanism and Related Hazards. ed. / Jose Luis Palma; Hugo Delgado Granados; William I. Rose; Nick Varley. Geological Society of America, 2013. p. 77-88 (Special Paper of the Geological Society of America; Vol. 498).

Research output: Chapter in Book/Report/Conference proceedingChapter

TY - CHAP

T1 - Gravity and geodesy of concepción volcano, Nicaragua

AU - Saballos, José Armando

AU - Malservisi, Rocco

AU - Connor, Charles B.

AU - Lafemina, Peter Christopher

AU - Wetmore, Paul

PY - 2013/1/1

Y1 - 2013/1/1

N2 - Concepción is currently the most active composite volcano in Nicaragua. Ash explosions of small to moderate size (volcano explosivity index 1-2) have occurred on a regular basis. Gravity data collected on and around the volcano between 2007 and 2010 confi rm that a younger cone is built atop an older truncated edifi ce of denser material, predominantly lavas. The bulk density of the volcanic cone is 1764 kg m-3 (with an uncertainty of at least ± 111 kg m-3), derived from gravity data. This estimated bulk density is signifi cantly lower than densities (e.g., 2500 kg m-3) used in previous models of gravitational spreading of this volcano and suggests that the gravitational load of the edifi ce may be much lower than previously thought. The gravity data also revealed the existence of a possible northwest-southeast-oriented normal fault (parallel to the subduction zone). Episodic geodetic data gathered with dualfrequency global positioning system (GPS) instruments at fi ve sites located around the volcano's base show no signifi cant change in baseline length during 8 yr and 2 yr of observations along separate baselines. Structures deformed after the Tierra Blanca Plinian eruption ca. 19 ka, which signifi cantly altered the form and bulk density of the volcano, may be due to the spreading of the volcano, but may also be related to volcano loading, magmatic intrusions and their subsequent evolution, and other volcano-tectonic processes, or a combination of any of these factors. A joint interpretation of our gravity and geodetic GPS data of Concepción suggests that this volcano is not spreading in a continuous fashion; if it is episodically spreading, it is driven by magma intrusion rather than gravity. These results have important implications for volcanic hazards associated with Concepción Volcano. Although during the last 15 yr tephra fallout and volcanic debris fl ows (lahars) have been the pervasive hazards at this volcano, earthquakes from an eventual slip of the fault on the east-northeast side of the volcano (delineated from our gravity measurements) should be considered as another important hazard, which may severely damage the infrastructures in the island, and conceivably trigger a volcano fl ank collapse.

AB - Concepción is currently the most active composite volcano in Nicaragua. Ash explosions of small to moderate size (volcano explosivity index 1-2) have occurred on a regular basis. Gravity data collected on and around the volcano between 2007 and 2010 confi rm that a younger cone is built atop an older truncated edifi ce of denser material, predominantly lavas. The bulk density of the volcanic cone is 1764 kg m-3 (with an uncertainty of at least ± 111 kg m-3), derived from gravity data. This estimated bulk density is signifi cantly lower than densities (e.g., 2500 kg m-3) used in previous models of gravitational spreading of this volcano and suggests that the gravitational load of the edifi ce may be much lower than previously thought. The gravity data also revealed the existence of a possible northwest-southeast-oriented normal fault (parallel to the subduction zone). Episodic geodetic data gathered with dualfrequency global positioning system (GPS) instruments at fi ve sites located around the volcano's base show no signifi cant change in baseline length during 8 yr and 2 yr of observations along separate baselines. Structures deformed after the Tierra Blanca Plinian eruption ca. 19 ka, which signifi cantly altered the form and bulk density of the volcano, may be due to the spreading of the volcano, but may also be related to volcano loading, magmatic intrusions and their subsequent evolution, and other volcano-tectonic processes, or a combination of any of these factors. A joint interpretation of our gravity and geodetic GPS data of Concepción suggests that this volcano is not spreading in a continuous fashion; if it is episodically spreading, it is driven by magma intrusion rather than gravity. These results have important implications for volcanic hazards associated with Concepción Volcano. Although during the last 15 yr tephra fallout and volcanic debris fl ows (lahars) have been the pervasive hazards at this volcano, earthquakes from an eventual slip of the fault on the east-northeast side of the volcano (delineated from our gravity measurements) should be considered as another important hazard, which may severely damage the infrastructures in the island, and conceivably trigger a volcano fl ank collapse.

UR - http://www.scopus.com/inward/record.url?scp=84922258027&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84922258027&partnerID=8YFLogxK

U2 - 10.1130/2013.2498(05)

DO - 10.1130/2013.2498(05)

M3 - Chapter

AN - SCOPUS:84922258027

T3 - Special Paper of the Geological Society of America

SP - 77

EP - 88

BT - Understanding Open-Vent Volcanism and Related Hazards

A2 - Palma, Jose Luis

A2 - Granados, Hugo Delgado

A2 - Rose, William I.

A2 - Varley, Nick

PB - Geological Society of America

ER -

Saballos JA, Malservisi R, Connor CB, Lafemina PC, Wetmore P. Gravity and geodesy of concepción volcano, Nicaragua. In Palma JL, Granados HD, Rose WI, Varley N, editors, Understanding Open-Vent Volcanism and Related Hazards. Geological Society of America. 2013. p. 77-88. (Special Paper of the Geological Society of America). https://doi.org/10.1130/2013.2498(05)