Services on Demand
Journal
Article
Indicators
-
Cited by SciELO
-
Access statistics
Related links
-
Similars in SciELO
Share
Geofísica internacional
On-line version ISSN 2954-436XPrint version ISSN 0016-7169
Geofís. Intl vol.51 n.2 Ciudad de México Apr./Jun. 2012
Original paper
2 ¾ dimension modeling of the aeromagnetic anomaly of Volcán de Colima, western Mexico
Héctor LópezLoera
División de Geociencias Aplicadas, Instituto Potosino de Investigación Científica y Tecnológica, A.C., Camino a la Presa San José # 2055 Lomas 4a Sección, C. P. 78216 San Luis Potosí, S.L.P., México. *Corresponding author: hlopezl@ipicyt.edu.mx
Received: January 20, 2011.
Accepted: October 20, 2011.
Published on line: March 30, 2012.
Resumen
Se presentan los resultados de un modelo 2 ¾ D de la anomalía aeromagnética del Volcán de Colima ubicado en la porción sur del Complejo Volcánico de Colima. El modelo estructural documenta la presencia de una cámara magmática de forma alargada con una longitud mayor a los 10 km en la dirección nortesur y que se extiende más de 6.6 km al sur del Volcán de Colima. El máximo espesor de la cámara magmática está hacia el ESE del cráter del Volcán de Colima y tiene una extensión del orden de los 6.9 km. Hacia los bordes la cámara magmática presenta espesores del orden de los 820 m a 620 m al sur y norte respectivamente. Bajo el Volcán de Colima de localiza a una profundidad entre 4.9 y 1.2 km bajo el nivel del mar. El modelo geofísico es consistente con las propuestas de la migración nortesur de la actividad en el Complejo Volcánico de Colima.
Palabras clave: Volcán de Colima, anomalía magnética, modelo magnético, cámara magmática, magnetismo.
Abstract
Results of 2 ¾ D modeling of the aeromagnetic anomaly of Volcán de Colima, in the southern sector of the Colima Volcanic Complex are presented. The structural model documents the presence of a magma chamber with an elongated shape and a length greater than 10 km in a northsouth direction extending over 6.6 km south of Volcán de Colima. The maximum thickness of the magma chamber, around 6.9 km, is located to the ESE of the volcano. The edges of the magma chamber have thicknesses ranging from 820 m to 620 m to the south and north, respectively. The magma chamber under Volcán de Colima is located at depths of 4.9 and 1.2 km below sea level. The geophysical model is consistent with a proposed northsouth migration of activity in the Colima Volcanic Complex.
Key words: Volcán de Colima, magnetic anomaly, magnetic model, magmatic chamber, magnetism.
Introduction
The study of magnetic fields from the air has been extensively used in volcanic areas worldwide where it has proven its usefulness and potential in studying structural features (e.g., Hagiwara, 1965; Finn and Williams, 1987; Ueda et al., 1990; Hildenbrand et al., 1993; Nakatsuka, 1994; Gibson and Milligan, 1998; Fedi et al., 1998; LopezLoera and UrrutiaFucugauchi, 1999; Garcia et al., 2007; Okuma et al., 2009; De Ritis et al., 2007, 2010a; Blanco Montenegro et al., 2011). In recent years aeromagnetometry has developed significantly with new instrumentation, survey methodologies, data processing and interpretation (e.g., UrrutiaFucugauchi et al., 2002; Finn and Morgan, 2002; BlancoMontenegro et al., 2003; Bournas et al., 2003; Ueda, 2007; Okuma et al., 2009; Okubo et al., 2009; Nakatsuka et al, 2009; De Ritis et al, 2010b; Pignatelli et al, 2011).
The effectiveness of aeromagnetic methods for determining the nature of surface and subsurface rocks is well established (Malahoff, 1969). An aeromagnetic anomaly reflects the spatial variation in the total magnetization of rocks measured by a magnetometer. Knowledge of the possible range of magnetization, and the recognition of factors that control magnetization, are essential for the interpretation of the geological significance of aeromagnetic data. The total magnetic intensity observed at a given point, is the vector sum of contributions of the natural remanent magnetization (NRM) and the induced magnetization (IM). At volcanic complexes in general, changes in quantity, grain size and composition of titanomagnetites produce most of the variations in the magnetization magnitude (Reynolds et al., 1990).
Aeromagnetometry has enabled the study of faults reactivation (Meridee, 1995), the evaluation of magnetic properties before and after volcanic eruptions (Finn and Williams, 1987; Nakatsuka et al., 2009), the establishment of the existence of volcanomagnetics belts (Honkura, 1991) and the study of the relationship with topography (Flanagan and Williams, 1982; UrrutiaFucugauchi et al., 2002; Okuma et al., 2009). Airborne magnetic methods have allowed the delineation of the lateral extent of structures such as rifts, caldera peaks, craters, fissures and ventilation fissures (Hildenbrand et al., 1993, LópezLoera et al., 2008, 2010). They have also allowed the investigation and identification of intrusive in the underground with no surface manifestations (Williams and Finn, 1987; De Ritis et al., 2010a).
The aeromagnetic research presented here aims to show the main magnetic elements that support magmatism migration from north to south in the Mexican Volcanic Belt, through a model that is based on an aeromagnetic survey conducted by the Mineral Resource Council (now the Mexican Geological Survey) covering the Colima Volcanic Complex.
Volcán de Colima
The Fire volcano or Volcán de Colima (Latitude 19° 30'50'' N, Longitude 103° 37'0'' W) is a composite volcano located in western Mexico, approximately 30 km north of the city of Colima (Figure 1). It has an elevation of 3,850 m above sea level and its located 175 km north the Middle American trench. Volcán de Colima is the youngest volcano in quaternary volcanic complex formed by the volcanoes Nevado and El Cántaro. The Colima Volcanic Complex and the Colima Rift have often been the focus of scientific research; examples include Luhr and Carmichael (1980, 1981, 1990), Robin et al.; (1990, 1991), Urrutia Fucugauchi et al., (1997), Bandy et al., (1993, 1995), LópezLoera and Gutiérrez (1977), LópezLoera et al., (1999, 2010).
Volcán de Colima is 5.5 km south of the volcano Nevado. It most likely became active when activity in Nevado ceased. The activity of Nevado de Colima with an old volcano called PaleoFire withan estimated age of 50 ka (Robin et al., 1987) was characterized by the collapse of the cone in an avalanche type similar to Mt. St. Helens, with a volume of 2233 km3 (Stoopes and Sheridan, 1992). The Colima avalanche extended 120 km to the south, reaching the Pacific coast. Recent studies (Capra, 2000) consider that these deposits did not reach the cost as primary deposits, but are instead the product of a secondary lahar. Volcán de Colima is characterized by major explosions and avalanche events, including volcanic debris of the Mt. St. Helens type, which formed a caldera 5 km in diameter in the form of horseshoe. For the Volcán de Colima avalanche, Robin et al. (1987) reported radiocarbon dates of 9,370 ± 400 years BP, for a sample of charcoal from a pyroclastic deposit above the avalanche. Luhr and Prestegaard (1988) found an age of 4,280 ± 110 years BP for a sample of coal underlying the debris avalanche deposit. Komorowski et al. (1996) suggest an age of 2.5 ka for the last collapse of the volcano. This author and colleagues consider that the Colima volcanoes have collapsed at least 12 times in the last 45 ka and that probably 9 events have been to the south. Komoroswski et al. (1996), dated five welldefined avalanches with ages ranging from 18,553 to 2,565 BP. After the last avalanche, an andesitic cone began to grow within the caldera. This cone has become Volcán de Colima.
Aeromagnetic Survey
The aerial survey was conducted by the Mineral Resources Council in 1999 as part of a research program to understand geological and structural conditions, mainly for the selection of prospective mining areas. The study was conducted with flight lines every 1,000 m with an NS direction and with an average height of 300 m above ground level. The aircraft was a B27 BN2 Islander, using a CS2 cesium magnetometer with a resolution of 0.001 nT with fixed sensor. Digital compilation was performed with aircraft motion correction (magnetic compensation), diurnal variation correction and subtraction of the International Geomagnetic Reference Field (IGRF 1995) (Barton et al., 1996). The digital information obtained by this survey was integrated and processed by generating a data grid with a cell size of 200m × 200m (Pascacio, 2001).
Further processing and modeling were performed in our lab using Geosoft software Oasis Montaj data processing and GMSYSTM magnetic modeling software. Mathematical algorithms were applied to calculate reduced to magnetic pole (Baranov and Naudy, 1964) and analytical upward continuations (Henderson and Zietz, 1949; Henderson 1970; Blakely, 1995).
A digital elevation map of the Nevado and Colima volcanoes shows that Nevado is a larger volcanic structure than Volcán de Colima. There are wide areas of canyons and the zone of the Colima protovolcano is characterized by remnants of a crater rim that can be seen north of the volcanic structure (Figure 2).
Aeromagnetic anomaly
Volcán de Colima is characterized by a residual magnetic field configuration associated with a normal dipolar anomaly, i.e., the magnetic high is located to the south and the magnetic low to the north (Figure 3). The contour map of the reduced to the magnetic pole of Volcán de Colima shows an elongated anomaly of triangular shape prolonged in the NNESSW direction and reaching maximum amplitude on the order of 1,000 nT (Figure 4). The crater is 1,450 m towards the WNW of the maximum magnetic amplitude. Nevado shows a magnetic anomaly in the L form, which has changed its direction from NNESSW to EW to the south. The anomaly consists of three magnetic highs with amplitudes of 466 nT, east of the crater, 505 nT to the NW of the crater and 545 nT to the north of the volcano summit. The Colima and Nevado volcanic structures form a single aeromagnetic domain differentiated by an ENEWSW alignment, which correlates with a fault zone that should exist between these two volcanoes (LópezLoera et al., 2010).
The map generated by the analytic signal and upward continued 2 km of the reduced to the magnetic pole, shows three magnetic anomalies. One of them is clearly associated with the circular structure of Volcán de Colima, placing the crater towards the west portion of maximum intensity. The other two anomalies seem to be closely related and are elongated in the EW direction. The remnant crater of Nevado is located south of these anomalies at a distance greater than 3 km (Figure 5).
Magnetic properties
The magnetic properties in the Colima volcanic complex have been reported by UrrrutiaFucugauchi et al. (1997), Coonor et al. (1993) and LópezLoera and UrrutiaFucugauchi (1999). The Coonor et al. (1993) study includes samples of the crater dome. Magnetic susceptibilities of five representative samples are reported in the range between 2.61 and 8.16 x 105 SI. Data for remanent magnetization intensities range from 1.08 to 3.84 A/m. Three samples show a discrete blocking temperature higher than 450 to 575° C, and two samples show a narrow range of unlocked temperatures.
LópezLoera and UrrutiaFucugauchi (1999) measured the magnetic properties of 50 samples collected along a transect between Atenquique and El Playón. This section runs along a general direction from the east (Atenquique) to the west (El Playón) and reaches the central portion of the Volcán de Colima. The natural remanent magnetization was measured with a Molspin spinner magnetometer. Low field magnetic susceptibilities were measured with a MS2 Bartington susceptibilimeter. LópezLoera and UrrutiaFucugauchi (1999) found that the magnetic properties of fragments in the volcanic debris avalanche of Nevado de Colima and Colima have a great range of variation. The magnetic susceptibilities of the avalanche of Nevado de Colima vary between 3.66 and 10.64 × 105 SI, with an average of 7.23 × 105. Remanent magnetization intensities range from 0.55 to 1.86 A/m. Samples of the recent avalanche of Volcán de Colima show ranges and averages for the magnetic susceptibility and intensity of remanence of 1.288.36 × 105 SI and 5.35 × 105 SI and 0.733.69 A/m with an average of 2.52 A/m, respectively.
Samples of andesitic lava from Nevado de Colima have remanence and susceptibilities intensities of 2.5 10 × 105 SI and 6.2 × 105 SI and 0.377.33 A/m with an average of 0.56 A/m respectively. Historic lava samples from the east wall of the Volcán de Colima caldera, show susceptibilities and remanence intensities of 4.29.8 × 105 SI and 5.8 × 105 SI and 0.81.0 A/m with an average of 0.88 A/m respectively.
The magnetic polarity of all units is normal, and in accordance with the age of the Colima Volcanic Complex. Therefore, the remanent magnetization direction remains constant and close to the dipole value with an inclination of 45 degrees and declination towards the north.
Aeromagnetic model
In order to document the magmatism migration from north to south across the volcanic complex of the Mexican Volcanic Belt (Luhr and Carmichael, 1990) an attempt has been made to model the magnetic response of the southern Colima Volcanic Complex and to determine if there could be magnetic elements to support such migration.
A 2 ¾ D model of the magnetic anomaly reduced to magnetic pole and upward continued 3 km, including Volcán de Colima and Nevado de Colima (Figure 6) was constructed. The anomaly was modeled by polygonal bodies with different magnetizations. The geometry and the magnetic properties of the sources associated with the anomaly were modeled using the GMSYSTM software; this inversion routine utilizes a Marquardt inversion algorithm (Marquardt, 1963) to linearize and invert the calculations. GMSYSTM uses an implementation of this algorithm for magnetic data processing developed by the USGS in the computer program SAKI (Webring, 1985).
Rock samples for magnetic studies were obtained from different lithological units: andesitic flows and breccias, as well as pyroclastic deposits of volcanic debris avalanches (Coonor et al., 1993; UrrutiaFucugauchi et al., 1997; LopezLoera and UrrutiaFucugauchi, 1999). Average values for the susceptibilities and remanent magnetization intensity were used as initial values in the model. While the magnetic polarity of all units is normal, according to the age of the Colima Volcanic Complex. A major limitation in the analysis is the lack of information related to the variation of the magnetic properties with depth.
Results and discussion
The model of the reduced to magnetic pole and upward continued 3 km (Figure 7), shows the existence of a magmatic chamber of elongated shape with a length greater than 10 km in the NS direction. The edges of this chamber have thicknesses ranging from 820 m to 620 m to the south and north respectively. To the ESE of the summit of Volcán de Colima the magmatic chamber has a maximum thickness of about 6.9 km. Therefore the conduit may have a length of about 4.9 km. Values of magnetic susceptibility and remanence do not exist for the magma chamber since by definition it must have temperatures higher than the Curie point (Table 1).
Although numerous papers have been published on the Colima volcanic complex, the issue of the magma chamber has hardly been addressed. Based on the distribution of located epicenters of earthquakes during the seismic crisis of 19971998, Zobin et al. (2002), mentioned that the free zone of earthquakes may be associated with the magma storage area and that this area is set at a depth on the order of 3.3 km. Existing charts tend to give a triangular shape to the magma chamber underlying Volcán de Colima. However MedinaMartínez et al. (1996) modeled the magma chamber of the Volcán de Colima using gravimetric data and determined the magmatic chamber to have rectangular shape more than 2 km wide, 5 km length and located about 1.5 km below sea level.
To place appropriated limits on the model, the Maeda viscoelastic model by CabreraGutierrez and Espindola (2010) was also analyzed. They modeled the Volcán de Colima eruption of 19981999. Based on observed data for the volume of material produced during the eruption, they reported a magmatic chamber of approximately 1.93 km in radius centered at ~1.7 km below sea level which is ~5.6 km beneath the crater. The roof of the magma chamber generated by the model in the magnetic study presented here has a maximum depth of 4.9 km. Based on the model used in this research, the chamber is about a 1.4 km below sea level, and has a maximum length of 6.9 km to depth.
The magnetic model of the internal structure of Volcán de Colima, has some limitations due primarily to the fact that the magma chamber itself does not generate any magnetic response because in principle within it magnetic properties are undefined, so the principal magnetic response comes mainly from the overlying geologic units. The contact zone between the magma chamber and the host rocks becomes very susceptible to any small change in the magma chamber host rock configuration, creating contrasting changes between measured field and the calculated field. In addition, the lack of magnetic properties at depth means that the magnetic response mainly comes from the underlying geologic unit. Therefore, the process of modeling is difficult and has to be refined with respect to the contour of the chamberhost rock contact to achieve an acceptable fit.
The migration of magmatism from north to south appears to be one of the main features of the Mexican Volcanic Belt (MVB). Evidence of migration of eruptive activity to the south may be found in the elongated volcanic chains at three major volcanic complexes (Volcán de ColimaNevadoCántaro; PopocatépetlIzztacihuatlTelapón; Pico de Orizaba (Citlaltepetl)Cofre de Perote) in the MVB, where older stratovolcanoes are located to the north and young active volcanoes are located to the south (Luhr and Carmichael, 1990). Thus Cofre de Perote is older than Pico de Orizaba and Iztaccihuatl is older than Popocatepetl, and Cántaro is older than Nevado and the Volcán de Colima. Towards the eastern portion of the MVB, Cantagrel and Robin (1979) using found that the migration of volcanism dates to the Pliocene using KAr dating. Hasenka and Carmichael (1985) investigated the ages of numerous cinder cones of the MichoacánGuanajuato volcanic field, in the middle portion of the MVB. Most of the cinder cones dated by Hasenka and Carmichael (1985) thought to be less than 40 thousand years old. All of these cones were located in the south. Cones located to the north were found to be older and are more eroded (Luhr and Carmichael, 1990). In addition, some researchers suggest that the MVB magmatism migration may reflect a change in subduction angle of the Cocos Plate (e.g., Urrutia Fucugauchi and Del Castillo, 1977).
Conclusions
The model of reduced to the magnetic pole field and upward continued 3 km described in this paper, shows elements that support the migration of magmatism from north to south in the Mexican Volcanic Belt and particularly in the Colima Volcanic Complex. The aeromagnetic model supports migration to the south of the Volcán de Colima (from the center of the body that simulates the magma chamber) of around 6.6 km.
The Volcán de Colima magma chamber model generated in this study has certain similarities with the gravity model of MedinaMartínez et al. (1996) and with the viscoelastic model by CabreraGutierrez and Espindola,differs from the conception described by Zobin et al. (2002), they have a classic pattern in terms of shape and position of the magma storage area, and the model shows no traces of magmatism migration, although their study was designed to investigate the seismic activity, and not to interpret the magma chamber.
Acknowledgments
This project has been supported by a scholarship for Ph.D. studies from Consejo Nacional de Ciencia y Tecnología (CONACYT) to the author. Special thanks to Dr. Tonatiuh Dominguez, from Red Sísmica de Colima (RESCO) at the Universidad de Colima, for his kindness in providing the seismic events of 19971998. I gratefully acknowledge comments and useful suggestions by anonymous journal reviewers on earlier versions of the paper. Thanks are also given to Dr. Jaime UrrutiaFucugauchi and Dr. Andrea Pavlick for comments that resulted in a more comprehensible, appropriate and improved manuscript.
Bibliography
Bandy W., MorteraGutiérrez C., UrrutiaFucugauchi J., 1993, Gravity field in the southern Colima graben. Mexico. Geofísica Internacional, 32, 561567. [ Links ]
Bandy W., MorteraGutiérrez C., UrrutiaFucugauchi J., Hilde T.W.C., 1995, The subducted RiveraCocos plate boundarywhere is it, what is it and what is it its relationship to the Colima rift? Geophys. Res. Lett. 22, 30753078. [ Links ]
Baranov V., Naudy H., 1964, Numerical calculation of the formula of reduction to the magnetic pole. Geophysics, 29, 6779. [ Links ]
Barton C.E., Balwin R.T., Barraclough D.R., Bushati S., Chiappini M., Cohen Y., Coleman R., Hulot G., Kotze P., Golovkov V.P., Jackson A., Langel R.A., Lowes F.J., McKnight D.J., Macmillan S., Newitt L.R., Peddi N.W., Quinn J.M., Sabaka T.J., International Geomagnetic Reference Field, 1995, revision, 1996, Presented by IAGA Division V, Working Group 8, Physics of Earth and Planetary Interiors, Vol. 97, DOI: 10.1016/00319201(96)031391. [ Links ]
Blakely R.J., 1995, Potential Theory in Gravity and Magnetic Applications. Cambridge University Press, 441 pp. [ Links ]
BlancoMontenegro I., Miquel Torta J., García A., Araña V., 2003, Analysis and modeling of the aeromagnetic anomalies of Gran Canaria (Canary Islands). Earth and Planetary Science Letters 206, 601616. [ Links ]
BlancoMontenegro I., Nicolasi I., Pignatelli A., García A., Chiappini M., 2011, New evidence about the structure and growth of ocean island volcanoes from aeromagnetic data: The case Tenerife, Canary Islands. J. Geophys. Res., 116, B03102, doi:10.1029/2010JB007646. [ Links ]
Bournas N., Galdeano A., Hamoudi M., Baker H., 2003, Interpretation of the aeromagnetic map of Eastern Hoggar (Algeria) using Euler deconvolution, analytic signal and local wavenumbers methods. Journal of African Earth Sciences. 37, 191205. [ Links ]
CabreraGutiérrez R., Espindola J.M., 2010. The 19981999 eruption of Volcán de Colima, Mexico: an application of Maeda's viscoelastic model. Geofísica Internacional 49 (2), 8396. [ Links ]
Cantagrel J.M., Robin C., 1979, KAr dating on Eastern Mexican volcanic rocks; relations between the andesitic and the alkaline provinces. Journal of Volcanology and Geothermal Research. 5, 99114. [ Links ]
Capra P. L., 2000, Colapso de edificios volcánicos: transformación de avalanchas de escombros en flujos de escombros cohesivos, los casos del monte Santa Elena (EE.UU.), Nevado de Toluca y Nevado de Colima (México). Inst, de Geofísica, UNAM, Tesis Doctoral, 120 pp. [ Links ]
Coonor C.B., Lane S.B., Clement B.M., 1993, Structure and thermal Characteristics of the summit dome, March, 1990March, 1991; Volcan Colima. Geofísica Internacional, 32, p 643657. [ Links ]
De Ritis R., Ventura G., Chiappini M., 2007, Aeromagnetic anomalies reveal hidden tectonic and volcanic structures in the central sector of the Aeolian Islands, southern Tyrrhenian Sea, Italy. J. Geophys. Res., 112, B10105, doi: 10.1029/2006JB004639. [ Links ]
De Ritis R., Dominici R., Ventura G., Nicolasi I., Chiappini M., Speranza F., De Rosa R., Donato P., Sonnino M., 2010a, A buried volcano in the Calabrian Arc (Italy) reveled by high resolution aeromagnetic data. J. Geopys. Res., 115, B11101, doi:10.1029/2009JB007171. [ Links ]
De Retis R., Ventura G., Chiappini M., Carluccio R., Von Frese R., 2010b, Regional magnetic and gravity anomaly correlations of the Southern Tyrrhenian Sea. Phys. Earth Planet. Int., Vol. 181, doi:10/1016/j.cageo.2010.10.003. [ Links ]
Fedi M., Florio G., Rapolla A., 1998, A 2.5 modeling of SommaVesuvius structure by aeromagnetic data. Journal of Volcanology and Geothermal Research. 82, 239247. [ Links ]
Finn C., Williams D.L., 1987, An Aeromagnetic Study of Mount St. Helens. J. Geophys, Res., 92, 10,194206. [ Links ]
Finn C.A., Morgan L.A., 2002, HighResolution aeromagnetic mapping of volcanic terrain, Yellowstone National Park, 2002. Journal of Volcanology and Geothermal Research 115, 207231. [ Links ]
Flanagan G., Williams D.L., 1982, A magnetic investigation of Mount Hood. Oregon, Journal of Geophysical Research B, 87, 4, 28042814. [ Links ]
Garcia A., Chiapini M., BlancoMontenegro I., Carluccio R., D'AjelloCaracciolo F., De Ritis R., Nicolasi I., Pignatelli A., Sánchez N., Boschi E., 2007, High resolution magnetic anomaly map of Tenerife, Canary Islands. AnnalGeophysics; Eds. M. Chiappini, A. García, v. 50, no. 5, 689697. [ Links ]
Gibson R.I., Milligan P.S., (Eds.), 1998, Geologic Applications of Gravity and Magnetics: Case Histories. Soc. Expl. Geophys., Geophys. Ref. Series 8, 162 pp. [ Links ]
Hagiwara Y., 1965, Analysis of the Results of the Aeromagnetic Surveys over Volcanoes in Japan (I). Bull. Earth. Res. Inst., 43, 529547. [ Links ]
Hasenka T., Carmichael I.S.E., 1985, The cinder cones of MichoacánGuanajuato, central Mexico; their age, volume and distribution, and magma discharge rate. Journal of Volcanology and Geothermal Research 25, 105124. [ Links ]
Henderson R.G., 1970, On the validity of the use of the upward continuation integral for total magnetic intensity data. Geophysics, 35, 916919. [ Links ]
Henderson R.G., Zietz I., 1949, The upward continuation of anomalies in total magnetic intensity fields. Geophysics, 14, 517534. [ Links ]
Hildenbrand T.G., Rosenbaum J., Kauahikaua J.P., 1993, Aeromagnetic Study of the Island of Hawaii. J. Geophys. Res., 98, 40994119. [ Links ]
Honkura Y., 1991, A Magnetic Anomaly Map in the Japanese Region with Special Reference to Tectonic Implication. J. Geomagn. Geoelectr., 43, 7183. [ Links ]
Komorowski J.C., Cortés A., Navarro C., Gavilanes J.C., Siebe C., Rodríguez S., 1996, Edifice collapse and debris avalanches deposits at Colima volcanoes, México a review with new variations on a recurrent theme: Univ. de Colima. Reunión Inter. Volcán de Colima. 5a, Colima, Col. (large abstract, electronic format). [ Links ]
LópezLoeraH.,GutiérrezC.,1977,Pseudosecciones Geoeléctricas e Implicaciones Geohidrológicas en el Valle de Colima. Geofísica Internacional, 17, 2, 127150. [ Links ]
LópezLoera H., UrrutiaFucugauchi J., 1999, Spatial and temporal magnetic anomalies of Colima volcano, western Mexico. Geofísica Internacional, 39, 316. [ Links ]
LópezLoera H., ArandaGómez J.J., Arzate J.A., MolinaGarza R.S., 2008, Geophysical surveys of the Joya Honda mar (México) and surroundings; volcanic implications. Journal of Volcanology and Geothermal Research 170, 135152. [ Links ]
LópezLoera H., UrrutiaFucugauchi J., AlvaValdivia L.M., 2010, Magnetic characteristics of fracture zones and constraints on the subsurface structure of the Colima Volcanic Complex, western Mexico. Geological Society of America, Geosphere 6, 1, 3546. [ Links ]
Luhr J.F., Carmichael I.S.E., 1980, The Colima Volcanic Complex, Mexico. Part I, Postcaldera andesites from Volcan Colima. Contrib. Mineral. Petrology, 71, 343372. [ Links ]
Luhr J.F., Carmichael I.S.E., 1981, The Colima Volcanic Complex, Mexico. Part II, Late Quaternary cinder cones: Contrib. Mineral. Petrology, 76, 127147. [ Links ]
Luhr J.F., Carmichael I.S.E., 1982, The Colima Volcanic Complex, Mexico. Part III. Ash and scoriafall deposits from the upper slopes of Volcan Colima: Contrib.Mineral. Petrology, 80, 262275. [ Links ]
Luhr J.F., Carmichael I.S.E., 1990, Geology of Volcan de Colima. Bol. Inst. Geol:, UNAM, 107, 101p. [ Links ]
Luhr J.F., Prestegaard K.L., 1988, Caldera formation at Volcan Colima, Mexico, by a large Holocene volcanic debris avalanche. J. Volcanol. Geotherm. Res., 35, 335348. [ Links ]
Malahoff A., 1969, Magnetic Studies over Volcanoes in the Earth's Crust and Uppermantle. Geophys. Monograph 13, edited by J. H. Pernbroke, Am. Geophysical Union 436446. [ Links ]
Marquardt D.W., 1963, An algorithm for leastsquares estimation of nonlinear parameters. J. SIAM, 11, 431441. [ Links ]
Medina F., Espindola J.M., De la Fuente M., Mena M., 1996, A Gravity model of the Colima, Mexico region. Geofísica Internacional 35 (4), 409414. [ Links ]
Meridee J.C., 1995, Structural controls of Holocene reactivation of the Meer fault, Southwestern Oklahoma, from magnetic studies. Geological Society of America, Bulletin, 107,1, 98112. [ Links ]
Nakatsuka T., 1994, Aeromagnetic anomalies over the area of Unzendake volcano. J. Geomagn. Geoelectr., 46, 529540. [ Links ]
Nakatsuka T., Utsugi M., Okuma S., Tanaka Y., Hashimoto T., 2009, Detection of aeromagnetic anomaly change associated with volcanic activity: An application of the generalized mistie control method. Tectonophysics. 478, 3 18. [ Links ]
Okubo A., Kanda W., Tanaka Y., Ishihara K., Miki D., Utsugi M., Takayama T., Fukushima M., 2009, Apparent magnetization intensity map on Sakurajima Volcano, Kyushu, Japan, inferred from lowaltitude, high density helicopterborne aeromagnetic surveys. Tectonophysics. 478, 3442. [ Links ]
Okuma S., Stotter Ch., Supper R., Nakatsuka T., Furukawa R., Motschka K., 2009, Aeromagnetic constrains on the subsurface structure of Stromboli Volcano, Aeolian Islans, Italy. Tectonophysics 478, 1933. [ Links ]
Pascacio R.P., 2001, Texto Guía Carta Magnética "Colima" E133, Consejo de Recursos Minerales, 12p. [ Links ]
Pignatelli A., Nicolosi I., Carluccio R., Chiappini M., vonFrese R., Chiappini M., 2011, Graphical interactive generation of gravity and magnetic fields. Computers and Geosciences, doi:10.1029/2010JB007646. [ Links ]
Reynolds R.L., Rosenbaum J.G., Hudson M.R., Fishman N.S., 1990, Rock magnetism, the distribution of magnetic minerals in the Earth's crust, and aeromagnetic anomalies, in Geologic Applications of Modern Aeromagnetics Surveys, U.S. Geol. Surv. Bull., 1924, 2445. [ Links ]
Robin C., Mossand P., Camus G., Cantagrel J.M., Vincent P., 1987, Eruptive history of the Colima volcanic complex (Mexico). J. Volcanol. Geotherm. Res., 31, 99113. [ Links ]
Robin C., Komorowsi J.C., Boudal C., Mossand P., 1990, Mixed magma pyroclastic surge deposits associated with debris avalanche deposits at Colima Volcanoes, Mexico. Bull. Vulcanol., 52, 391403. [ Links ]
Robin C., Camus G., Gourgaund A., 1991, Eruptive and magmatic cycles at Fuego de Colima (Mexico). J. Volcanol. Geotherm. Res., 45, 209225. [ Links ]
Stoopes G., Sheridan M.F., 1992, Giant debris avalanches from the Colima volcanic complex, Mexico implications for longrun out landslides (> 100 km) and hazard assessment. Geology, 20, 299302. [ Links ]
Ueda Y., 2007, A 3D magnetic structure of IzuOshima Volcano and their changes after the eruption in 1986 as estimated from repeated airborne magnetic surveys. Journal of Volcanology and Geothermal Research 164, 176192. [ Links ]
Ueda Y., Nakagawa H., Kumagwa K., 1990, Aeromagnetic Anomaly and Derived Structure of IzuOshima Volcano after the eruption in November, 1986. J. Geomag. Geoelectr., 42, 355363. [ Links ]
UrrutiaFucugauchi J., Del Castillo L., 1977, Un modelo del Eje Neovolcánico Mexicano. Bol. Soc. Geol. Mex., 38, 1828. [ Links ]
UrrutiaFucugauchi J., Martín del Pozzo A.L., AlvaValdivia L., LópezLoera L., Ponce R., 1997, Paleomagnetic estimates of emplacement temperatures of pyroclastic deposits from the Colima volcanic complex. Intern, Assoc. Volcanol. Geochem. Earth Inter., IAVCEI General Assembly, January 1997, Puerto Vallarta, Mexico, Abstr. P.12. [ Links ]
UrrutiaFucugauchi J., MartínezPepin N., HernándezPérez I., ArciniegaCeballos A., LópezLoera H., FloresRuiz J.H., Anaya C., 2002, Aeromagnetic anomalies and structure of the IztaccíhuatlPopocatépetl volcanic region in Central Mexico. Geofísica Internacional, 41,2, 121131. [ Links ]
Webring M., 1985, SAKI: a FORTRAN program for generalized inversion of gravity and magnetic profiles. USGS Open File Report 85122, 29p. [ Links ]
Williams D.L., Finn C., 1987, Evidence for shallow pluton beneath the Goat Rocks Wilderness, Washington, from gravity and magnetic data: Journal of Geophysical Research, 92, 48674880. [ Links ]
Zobin V.M., Luhr J.F., Taran Y.A., Breton M., Cortés A., De La CruzReyna S., Dominguez T., Galindo I., Gavilanes J.C., Muñiz J.J., Navarro C., Ramírez J.J., Reyes G.A., Ursua M., Velasco J., Alatorre E., Santiago H., 2002, Overview of the 19972000 activity of Volcán de Colima, México. Journal of Volcanology and Geothermal Research. 117, 119. [ Links ]