Constraints on magma chamber geometry at Sierra Negra Volcano, Galápagos Islands, based on InSAR observations

Yun, Sang‐Ho; Segall, P.; Zebker, H. A.

doi:10.1016/j.jvolgeores.2005.07.009

Cited by 148 publications

(121 citation statements)

References 21 publications

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“…Moreover, we do not have a good a priori knowledge of the host rock stress, thus, of the overpressure. Using a constant stress model for dikes leads to a smoothly varying opening on the fracture [Cayol and Cornet, 1997], consistent with results obtained from linear kinematic inversions of opening distributions [Yun et al, 2006;Pallister et al, 2010]. We invert the dike and fault geometries simultaneously with uniform stress vectors, leading to a minimum of 7 parameters per structure.…”

Section: Three-dimensional Boundary Element Modelingsupporting

confidence: 78%

Magma sources involved in the 2002 Nyiragongo eruption, as inferred from an InSAR analysis

Wauthier¹,

Cayol²,

Kervyn³

et al. 2012

J. Geophys. Res.

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along a 20 km-long fracture network extending from the volcano to the city of Goma. The event was captured by InSAR data from the ERS-2 and RADARSAT-1 satellites. A combination of 3D numerical modeling and inversions is used to analyze these displacements. Using Akaike Information Criteria, we determine that a model with two subvertical dikes is the most likely explanation for the 2002 InSAR deformation signal. A first, shallow dike, 2 km high, is associated with the eruptive fissure, and a second, deeper dike, 6 km high and 40 km long, lies about 3 km below the city of Goma. As the deep dike extends laterally for 20 km beneath the gas-rich Lake Kivu, the interaction of magma and dissolved gas should be considered as a significant hazard for future eruptions. A likely scenario for the eruption is that the magma supply to a deep reservoir started ten months before the eruption, as indicated by LP events and tremor. Stress analysis indicates that the deep dike could have triggered the injection of magma from the lake and shallow reservoir into the eruptive dike. The deep dike induced the opening of the southern part of this shallow dike, to which it transmitted magma though a narrow dike. This model is consistent with the geochemical analysis, the lava rheology and the pre-and post-eruptive seismicity. We infer low overpressures (1-10 MPa) for the dikes. These values are consistent with lithostatic crustal stresses close to the dikes and low magma pressure. As a consequence, the dike direction is probably not controlled by stresses but rather by a reduced tensile strength, inherited from previous rift intrusions. The lithostatic stresses indicate that magmatic activity is intense enough to relax tensional stresses associated with the rift extension.

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Section: Three-dimensional Boundary Element Modelingsupporting

confidence: 78%

Magma sources involved in the 2002 Nyiragongo eruption, as inferred from an InSAR analysis

Wauthier¹,

Cayol²,

Kervyn³

et al. 2012

J. Geophys. Res.

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“…9). Earlier studies at a Galapagos caldera illustrated that a large magma chamber with a flat roof can produce the same amount and pattern of surface displacement as a thin sill (Yun et al, 2006). The finite source of the deformation at Lazufre may therefore be much larger than the volume change estimation presented here.…”

Section: Earthquake Triggering Of Magma Intrusionmentioning

confidence: 58%

“…If we consider a difference of temperature of 1000 K between the host rock and a sheet-like intrusion, the latter will completely solidify in about 1.5 h. InSAR data, however, shows a constant inflation over a time series of 9 years, implying that the magma body must be larger in order to remain fluid. We now follow an approach applied by Yun et al (2006) and inversely calculate the minimum magma chamber thickness required for 9 years long intrusion duration. Assuming that the source of the Lazufre deformation has been constantly active since 1998-2006, the initial thickness of the magma chamber would have been at least 30 m (for a 1000 K temperature difference).…”

Section: Earthquake Triggering Of Magma Intrusionmentioning

confidence: 99%

Caldera-scale inflation of the Lazufre volcanic area, South America: Evidence from InSAR

Ruch

Anderssohn

Walter

et al. 2008

Journal of Volcanology and Geothermal Research

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“…However, in order to explain the distribution and migration of the residuals between observations and models and their temporal migrations, it is useful to infer the existence of additional small scale deformation sources. Such additional local faults might be trapdoor faults resulting from intense magmatic activity during the 2003-2005 period [2] as shown in Sierra Negra Volcano [83]. However, we found that an improvement of the model inversion including a magma chamber, major fault lines based on [5] and a number of unknown local deformation sources were not possible to obtain due to many unconstrained parameters uncertainties.…”

Section: Interpretation Of Stamps/mti Processing Resultsmentioning

confidence: 93%

Investigation of Potential Volcanic Risk from Mt. Baekdu by DInSAR Time Series Analysis and Atmospheric Correction

et al. 2017

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Abstract:Mt. Baekdu is a volcano near the North Korea-Chinese border that experienced a few destructive eruptions over the course of its history, including the well-known 1702 A.D eruption. However, signals of unrest, including seismic activity, gas emission and intense geothermal activity, have been occurring with increasing frequency over the last few years. Due to its close vicinity to a densely populated area and the high magnitude of historical volcanic eruptions, its potential for destructive volcanic activity has drawn wide public attention. However, direct field surveying in the area is limited due to logistic challenges. In order to compensate for the limited coverage of ground observations, comprehensive measurements using remote sensing techniques are required. Among these techniques, Differential Interferometric SAR (DInSAR) analysis is the most effective method for monitoring surface deformation and is employed in this study. Through advanced atmospheric error correction and time series analysis, the accuracy of the detected displacements was improved. As a result, clear uplift up to 20 mm/year was identified around Mt. Baekdu and was further used to estimate the possible deformation source, which is considered as a consequence of magma and fault interaction. Since the method for tracing deformation was proved feasible, continuous DInSAR monitoring employing upcoming SAR missions and advanced error regulation algorithms will be of great value in monitoring comprehensive surface deformation over Mt. Baekdu and in general world-wide active volcanoes.

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Constraints on magma chamber geometry at Sierra Negra Volcano, Galápagos Islands, based on InSAR observations

Cited by 148 publications

References 21 publications

Magma sources involved in the 2002 Nyiragongo eruption, as inferred from an InSAR analysis

Magma sources involved in the 2002 Nyiragongo eruption, as inferred from an InSAR analysis

Caldera-scale inflation of the Lazufre volcanic area, South America: Evidence from InSAR

Investigation of Potential Volcanic Risk from Mt. Baekdu by DInSAR Time Series Analysis and Atmospheric Correction

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