Publication Date:
2017-04-04
Description:
This survey proposes a new approach to identify buried caldera boundaries of a volcanic cone, combining (1) a systematic elliptic Fourier functions (EFF) analysis on the contour lines based on the external shape of the edifice with (2) self-potential (SP) measurements on volcano flanks. The methodology of this approach is to investigate the relationships between (1) vertical
morphological changes inferred from EFF analysis and (2) lateral lithological transition inside the edifice inferred from SP/elevation gradients. The application of these methods on Misti volcano in southern Peru displays a very good correlation. The three main boundaries evidenced by hierarchical cluster analysis on the contour lines coincide with the two main boundaries
characterised by SP signal and with a secondary SP signature related with a summit caldera. In order to explain these results showing a very good correlation between morphologic and lithologic changes as function of elevation, caldera boundaries have been suggested. The latter would be located at an average elevation of (1) 4350–4400 m, (2) 4950–5000 m, and (3) 5500–
5550 m.
For the lowest boundary in elevation, the coincidence with the lateral extension of the hydrothermal system inferred from SP measurements suggests that caldera walls act as a barrier for lateral extension of hydrothermal systems. In the summit area, the highest boundary has been related with the summit caldera, inferred by a secondary SP minimum and geological evidence.
Description:
- Institut de Recherche pour le Développement (IRD)
- Instituto Geofisico del Peru´ (IGP).
Description:
Published
Description:
283– 297
Description:
partially_open
Keywords:
caldera
;
elliptic Fourier functions
;
geomorphology
;
self-potential
;
Misti volcano
;
Peru
;
03. Hydrosphere::03.02. Hydrology::03.02.02. Hydrological processes: interaction, transport, dynamics
;
03. Hydrosphere::03.02. Hydrology::03.02.03. Groundwater processes
;
03. Hydrosphere::03.02. Hydrology::03.02.04. Measurements and monitoring
;
03. Hydrosphere::03.04. Chemical and biological::03.04.05. Gases
;
03. Hydrosphere::03.04. Chemical and biological::03.04.06. Hydrothermal systems
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04. Solid Earth::04.01. Earth Interior::04.01.02. Geological and geophysical evidences of deep processes
;
04. Solid Earth::04.02. Exploration geophysics::04.02.04. Magnetic and electrical methods
;
04. Solid Earth::04.04. Geology::04.04.03. Geomorphology
;
04. Solid Earth::04.04. Geology::04.04.09. Structural geology
;
04. Solid Earth::04.04. Geology::04.04.11. Instruments and techniques
;
04. Solid Earth::04.08. Volcanology::04.08.05. Volcanic rocks
;
05. General::05.02. Data dissemination::05.02.04. Hydrogeological data
;
05. General::05.05. Mathematical geophysics::05.05.99. General or miscellaneous
;
05. General::05.08. Risk::05.08.99. General or miscellaneous
;
04. Solid Earth::04.08. Volcanology::04.08.08. Volcanic risk
Repository Name:
Istituto Nazionale di Geofisica e Vulcanologia (INGV)
Type:
article
Format:
539 bytes
Format:
756700 bytes
Format:
text/html
Format:
application/pdf
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