Error estimation in multitemporal InSAR deformation time series, with application to Lanzarote, Canary Islands

Interferometric Synthetic Aperture Radar (InSAR) is a reliable technique for measuring crustal deformation. However, despite its long application in geophysical problems, its error estimation has been largely overlooked. Currently, the largest problem with InSAR is still the atmospheric propagation errors, which is why multitemporal interferometric techniques have been successfully developed using a series of interferograms. However, none of the standard multitemporal interferometric techniques, namely PS or SB (Persistent Scatterers and Small Baselines, respectively) provide an estimate of their precision. Here, we present a method to compute reliable estimates of the precision of the deformation time series. We implement it for the SB multitemporal interferometric technique (a favorable technique for natural terrains, the most usual target of geophysical applications). We describe the method that uses a properly weighted scheme that allows us to compute estimates for all interferogram pixels, enhanced by a Montecarlo resampling technique that properly propagates the interferogram errors (variance-covariances) into the unknown parameters (estimated errors for the displacements). We apply the multitemporal error estimation method to Lanzarote Island (Canary Islands), where no active magmatic activity has been reported in the last decades. We detect deformation around Timanfaya volcano (lengthening of line-of-sight ∼ subsidence), where the last eruption in 1730–1736 occurred. Deformation closely follows the surface temperature anomalies indicating that magma crystallization (cooling and contraction) of the 300-year shallow magmatic body under Timanfaya volcano is still ongoing.Peer reviewe

Screening and selection of reviews for inclusion.

<p>Screening and selection of reviews for inclusion.</p

Unique lists of salutogenically focused outcome domains.

<p>Unique lists of salutogenically focused outcome domains.</p

Data extraction process.

<p>Data extraction process.</p

Flow diagram of eDelphi process and core outcome generation.

<p>Flow diagram of eDelphi process and core outcome generation.</p

Round 1 of eDelphi: Rating for 38 potential core outcomes.

<p>Round 1 of eDelphi: Rating for 38 potential core outcomes.</p

Characteristics of participants.

<p>Characteristics of participants.</p

Round 2 of eDelphi: Rating for 34 potential core outcomes.

<p>Round 2 of eDelphi: Rating for 34 potential core outcomes.</p

Final “COS Adult Cardiac Surgery”.

<p>Final “COS Adult Cardiac Surgery”.</p

Western blot results of biomarkers of protein synthesis, proteolysis and oxidative stress in the diaphragm.

<p>A) pAKT/AKT ratio was analyzed as quotient of pAKT versus AKT expression. Representative blots for both AKT and pAKT are displayed above; Con n = 8, CMV n = 6, Ext 12 n = 8, Ext24 n = 8 B) The levels of 4-hydroxynonenal (4- <i>HNE</i>) were analyzed as an indicator of lipid peroxidation via Western blotting. A representative blot for 4-HNE protein conjugates is shown above the graph (Con n = 8, CMV n = 7, Ext 12 n = 8, Ext24 n = 8). C/D) Calpain (C) (Con n = 6, CMV n = 7, Ext 12 n = 7, Ext24 n = 8) and caspase-3 (D) (Con n = 7, CMV n = 7, Ext 12 n = 7, Ext24 n = 8) activations were determined via Western blotting as a ratio for the spectrin breakdown product (120 and 145 kDA band) compared to the 245 kDa band. Representative Western blots are shown above the graphs. CMV 12: Mechanical ventilation for 12 hours, Ext 12: 12 hours of spontaneous breathing after 12 hours of MV, Ext 24: 24 hours of spontaneous breathing after 12 hours of MV, CON: unventilated controls. Values are arbitrary units ± SD. * significant versus Control, # significant versus CMV; IDV integrated density value.</p