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| Titel |
Control of the geomorphic evolution of an active crater: Popocatpetl (Mexico) 1994-2003. |
| VerfasserIn |
N. Andrés, J. J. Zamorano, D. Palacios, J. L. Macias, J. J. Sanjosé |
| Konferenz |
EGU General Assembly 2009
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 11 (2009) |
| Datensatznummer |
250020217
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| Zusammenfassung |
| Volcanic activity often causes intense and successive geomorphic changes to occur inside a
crater. In terms of hazard mitigation, it is important to understand the cause of these
changes whether they be exterior lava spills, sequences of explosions or massive
glacier melt. Access to an active crater, however, is very difficult and dangerous, so
analytical approaches involving remote study must substitute actual fieldwork. Several
studies done at Popocatepetl volcano during its most recent eruptive phase that
began in December 1994, use remote techniques and are described in Cruz-Reyna
et al. (1998), Wright et al. (2002), Martín-Del Pozo et al. (2003), Tanarro et al.
(2005), Matiella et al. (2008), and Zamorano et al. (1996,1998), among others. The
compendium of results reveals that recent volcanic activity on Popocatépetl is characterized
by successive dome growth and destruction inside the crater. Macias and Siebe
(2005) even suggest that the walls of the crater may no longer withstand future dome
growth.
The purpose of this study is to understand the morphologic evolution of the interior of the
crater during the most active period of the present eruptive phase on Popocatepetl from 1994
to 2003. The methodology is based on photogrammetry techniques that have been used
successfully at volcanic sites by Donnadieu et al. (2003), and on a GIS to organize
information, draft maps and 3-D images, and to calculate spatial variations in landforms
(Procter et al., 2006; Schilling et al., 2006). Traditional aerial photo interpretation
was used for 22 triplets selected from a collection of photos taken by the Mexican
Highway and Transport Secretariat, from 1982 to 2003, and enabled us to draft
geomorphic maps of the interior of the crater. The photos and maps were rectified and
georeferenced with ArcGis software, and then the maps were digitized. The areas
containing morphologic units associated with a date (exterior crater walls, colluvial
ramps and recent volcanic complex features such as craters, cones and domes) were
uploaded to a temporal database. Next, we linked the morphologic description of
the craters and the surface variations occupied by each of the landforms with the
volcanic activity. Topographic restitution for 7 of the 22 pairs of selected aerial
photos was performed and the Digital Elevations Models (DEMs) for each date were
imported to ArcGis to analyze the variations in elevation at the base of the crater and
changes on the slopes. Finally, we calculated the free space inside the crater for each
date.
The results from the data processing showed a sequence of transformations in the crater,
each of which was identified with a specific type and intensity of volcanic activity. In the
pre-eruptive stage prior to 1994, the growth of the outer walls and the colluvial ramp of the
crater (90% of the crater) was attributed primarily to non-volcanic activity. The period from
1994 to June 1999, was marked by dome growth and destruction, which expanded the surface
area of the complex (34.5% in April 1998), but reduced the colluvial ramp and the wall.
Explosions ejected material from inside the crater, increasing its width and depth (48m).
Free space occupied 17.3x106 m3 in June1999, but after an interval of relative
calm, dome growth resumed in 2000. Larger forms were produced and were not
immediately destroyed, so the dome complex increased to 45.219 m2 by September
2001. This chain of events marked by the overlapping of domes and materials,
gave the recent volcanic complex an intricate morphology. During this time, the
depth of the crater in February 2003 was 66 m with 11.2x106 m3 of free space.
The July-August 2003 photograms reveal a morphology of craters created by a
succession of phreatomagmatic explosions that inhibited the formation of lava bodies.
Judging from descriptions by volcanologists in February 2004 (Macias and Siebe,
2005), the amount of material ejected from the crater by these explosions was not
substantial.
References.-
Cruz-Reyna, S. de la; Meli, R.; Macías, J.L.; Castillo, F.; & Cabrera, B., 1998. Cyclical
dome extrusions that by late 1997 filled one-third of crater capacity, In Smithsonian-GVP
Monthly Reports, Popocatépetl, Smithsonian Institution. Bull. Glob. Volcanism Netw, (GVN)
23 (2), 2 – 4.
Donnadieu, F.; Kelfoun, K.; Van Wyk de Vries, B.; Decchi, E.; & Merle, O.,
2003. Digital photogrammetry as a tool in analogue modelling: applications to
volcano instability, Journal of Volcanology and Geothermal Research, 123 (1-2),
161-180.
Macías, J.L. & Siebe, C., 2005. Popocatépetl crater filled to the brim: significance for
hazard evaluation, Journal of Volcanology and Geothermal Research (141) 327-330.
Martín-Del Pozzo, A.L.; Cifuentes-Nava, G.; Cabral-Cano, E.; Bonifaz, F.; Correa, I.; &
Mendiola, I.F., 2003. Timing magma ascent at Popocatepetl Volcano, Mexico, 2000-2001,
Journal of Volcanology and Geothermal Research ,125, 107-120.
Matiella, M.A.; Watson, I.M.; Delgado, H.; Rose, W.I.; , Cárdenas, L.; & Realmuro, V.J.,
2008, Volcanic emissions from Popocatépetl volcano, Mexico, quantified using Moderate
Resolution Imaging Spectroradiometer (MODIS) infrared data: A case study of the December
2000-January 2001 emissions, Journal of Volcanology and Geothermal Research, 170, 1-2,
76-85.
Procter, J.N.; Platz, T.; & Cronin, S.J., 2006. A remnant summit lava dome and
its influence on future eruptive hazards, Geophysical Research Abstracts, Vol. 8,
10211.
Schilling, S.P.; Ramsey, D.W.; Messerich, J.A.; & Thompson, R.A., 2006. Map:
Rebuilding Mount St. Helens. U.S. Geological Survey Scientific Investigations Map
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Tanarro, L. M.; Zamorano, J.J.; & Palacios, D., 2005. Glacier degradation and lahar
formation on the Popocatépetl volcano (Mexico) during the last eruptive period (1994-2003),
Zeitschrift Geomorphologie (140) 73-92.
Zamorano, J.J., Gómez, A. 1996 "Análisis geomorfoloógico a detalle,1:10 000 del cráter
del volcán Popocatépetl (1989-1996)" IV Reunión Nacional de Geomorfología. Pátzcuaro,
Michoacán. México.
Zamorano, JJ. Goméz, A. y Martín del Pozo, A. L. 1998 "Cartografía geomorfológica
del cráter del volcán Popocatépetl (Esc. 1:10 000): mayo 1989-abril 1998" Primera Reunión
Nacional de Ciencias de la Tierra. D.F. México.
Wright, R.; Cruz-Reyna, S. de la; Harris, A.; Flynn, L.; & Gomez-Palacios, J.J., 2002.
Infrared satellite monitoring at Popocatépetl: Explosions, exhalations, and cycles of dome
growth, Journal of Geophysical Research, 107(B8), 2153. |
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