Seasonal tropospheric influence on SAR interferograms near the ITCZ – The case of Fogo Volcano and Mount Cameroon

Heleno, Sandra; Frischknecht, Corine; d’Oreye, Nicolas; Lima, J. N.; Faria, Bruno; Wall, Robert; Kervyn, F.

doi:10.1016/j.jafrearsci.2009.07.013

Cited by 21 publications

(18 citation statements)

References 33 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The peak‐to‐peak annual amplitude of variations in the vertical component of the deformation time series observed at Vesuvius (elevation 1281 m) during the 2003–2013 period reaches 3 cm while the long‐term subsidence rate is less than 0.6 cm/yr. Seasonal oscillations of APD larger amplitudes occur at other stratovolcanoes, in particularly at Pico do Fogo (2829 m), Mount Etna (3350 m), and Mount Cameroon (4040 m), as was demonstrated by Wadge et al [] and Heleno et al []. Proposed here approach can be successfully used for correcting InSAR retrievals in those and other areas.…”

Section: Discussionmentioning

confidence: 99%

“…Processing of multitemporal InSAR imagery produces time series of ground deformation for events occurring over an extended period of time [Berardino et al, 2002;Hooper, 2008;Samsonov and d'Oreye, 2012]. InSAR retrievals are contaminated by the atmospheric signal, called the Atmospheric Path Delay (APD), at a magnitude often exceeding the deformation signal itself [Wadge et al, 2002;Heleno et al, 2010]. A precise atmospheric correction, applied to individual interferograms, requires an accurate knowledge of temporally and spatially colocated atmospheric profiles, which are not always easily available.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Removal of systematic seasonal atmospheric signal from interferometric synthetic aperture radar ground deformation time series

Samsonov

Trishchenko

Tiampo

et al. 2014

Geophysical Research Letters

View full text Add to dashboard Cite

Applying the Multidimensional Small Baseline Subset interferometric synthetic aperture radar algorithm to about 1500 Envisat and RADARSAT‐2 interferograms spanning 2003–2013, we computed time series of ground deformation over Naples Bay Area in Italy. Two active volcanoes, Vesuvius and Campi Flegrei, are located in this area in close proximity to the densely populated city of Naples. For the first time, and with remarkable clarity, we observed decade‐long elevation‐dependent seasonal oscillations of the vertical displacement component with a peak‐to‐peak amplitude of up to 3.0 cm, substantially larger than the long‐term deformation rate (<0.6 cm/yr). Analysis, utilizing surface weather and radiosonde data, linked observed oscillations with seasonal fluctuations of water vapor, air pressure, and temperature in the lower troposphere. The modeled correction is in a good agreement with observed results. The mean, absolute, and RMS differences are 0.014 cm, 0.073 cm, and 0.087 cm, respectively. Atmospherically corrected time series confirmed continuing subsidence at Vesuvius previously observed by geodetic techniques.

show abstract

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Removal of systematic seasonal atmospheric signal from interferometric synthetic aperture radar ground deformation time series

Samsonov

Trishchenko

Tiampo

et al. 2014

Geophysical Research Letters

View full text Add to dashboard Cite

show abstract

“…Under favourable conditions, long, dense timeseries of InSAR data can give uncertainties better than 1 mm per year66, but for a single interferogram at tropical volcanoes, errors can be as much as 17 cm (ref. 67). For ground-based networks such as GPS, the limitation is typically the number and location of instruments, particularly during large explosive eruptions as near-field sensors are often inoperable or destroyed.…”

Section: Methodsmentioning

confidence: 99%

Observing eruptions of gas-rich compressible magmas from space

2016

View full text Add to dashboard Cite

Observations of volcanoes from space are a critical component of volcano monitoring, but we lack quantitative integrated models to interpret them. The atmospheric sulfur yields of eruptions are variable and not well correlated with eruption magnitude and for many eruptions the volume of erupted material is much greater than the subsurface volume change inferred from ground displacements. Up to now, these observations have been treated independently, but they are fundamentally linked. If magmas are vapour-saturated before eruption, bubbles cause the magma to become more compressible, resulting in muted ground displacements. The bubbles contain the sulfur-bearing vapour injected into the atmosphere during eruptions. Here we present a model that allows the inferred volume change of the reservoir and the sulfur mass loading to be predicted as a function of reservoir depth and the magma's oxidation state and volatile content, which is consistent with the array of natural data.

show abstract

“…The comparison demonstrates a similar accuracy in measuring phase changes between the lower resolution (~16 × 16 m pixel size averaging one sample in azimuth and five in range) Sentinel-1 data and higher-resolution (~1 × 2 m pixel size) data from stripmap mode satellite missions (e.g., RADARSAT-2). Fogo Island has been reported as a challenging location when measuring ground deformation using InSAR because of extremely variable weather conditions due to the steep topography of the volcano, which can cause water vapor delays of up to five fringes in C band interferograms [Heleno et al, 2010]. For this reason, the qualitative comparison between Sentinel-1 and RADARSAT-2 interferograms becomes even more important to identify possible atmospheric contributions.…”

Section: 1002/2015gl066003mentioning

confidence: 99%

The 2014–2015 eruption of Fogo volcano: Geodetic modeling of Sentinel‐1 TOPS interferometry

González

Bagnardi

Hooper

et al. 2015

Geophysical Research Letters

120

View full text Add to dashboard Cite

After 20 years of quiescence, Fogo volcano erupted in November 2014. The eruption produced fast‐moving lava flows that traveled for several kilometers and destroyed two villages. This event represents the first episode of significant surface deformation imaged by the new European Space Agency's Sentinel‐1 satellite in its standard acquisition mode, Terrain Observation by Progressive Scans (TOPS), which differs from that of previous synthetic aperture radar (SAR) missions. We perform a Bayesian inversion of Sentinel‐1 TOPS SAR interferograms spanning the eruption and accurately account for variations in the TOPS line‐of‐sight vector when modeling displacements. Our results show that magma ascended beneath the Pico do Fogo cone and then moved laterally toward its southwestern flank, where the eruptive fissure opened. This study provides important insights into the inner workings of Fogo volcano and shows the potential of Sentinel‐1 TOPS interferometry for geophysical (e.g., volcano monitoring) applications.

show abstract

Seasonal tropospheric influence on SAR interferograms near the ITCZ – The case of Fogo Volcano and Mount Cameroon

Cited by 21 publications

References 33 publications

Removal of systematic seasonal atmospheric signal from interferometric synthetic aperture radar ground deformation time series

Removal of systematic seasonal atmospheric signal from interferometric synthetic aperture radar ground deformation time series

Observing eruptions of gas-rich compressible magmas from space

The 2014–2015 eruption of Fogo volcano: Geodetic modeling of Sentinel‐1 TOPS interferometry

Contact Info

Product

Resources

About