Table 2 Selected results of InSAR analysis during the LAPP for volcanoes listed from north to south

Soufriere Hills, Montserrat

Topographic changes associated with dome growth and pyroclastic density currents (Arnold et al. 2016)

Complements ground- and aerial DEMs

Popocatepetl^a, Mexico

Deformation observed of western flank in InSAR and GPS (Solano-Rojas et al. 2017)

Continued ground monitoring

Colima, Mexico^a

Ground deformation before Jan. 2013 explosion (Salzer et al. 2014)

Continued ground monitoring

Pacaya^ab, Guatemala

Magmatic processes, lava flow compaction and & flank motion have been detected by InSAR in 2013-1014 (Wnuk and Wauthier 2017)

Only monitoring data available beside one seismic station and sparse campaign GPS data. However, three new seismic stations were installed in 2016 and three new GPS monuments will be deployed as a result of the LAPP InSAR measurements

Santiaguito^a, Guatemala

Subsidence of deposits on the southern part of the active Caliente dome (Wauthier 2016) as previously identified by (Ebmeier et al. 2012)

Only monitoring data besides campaign tiltmeters and photogrammetry studies of the active Caliente dome (Johnson et al. 2014)

Fuego^a, Guatemala

Null results but coherence is poor even with ALOS-2 likely due to the volcano’s steep slopes

Limited ground-based monitoring (only one single short-period seismometer with low signal-to-noise ratio on the eastern flank)

Masaya^ab, Nicaragua

Ground deformation due to conduit processes associated with explosive eruptions in 2012 (Stephens et al. 2017). Uplift offset from active summit during unrest in 2015-2016 (Stephens and Wauthier 2018)

Only monitoring data available, besides few seismometers and 1 GPS station in the caldera and 1 in Managua city. New GPS stations are being installed as a result of the LAPP InSAR results

Momotombo^ab, Nicaragua

Lack of pre-eruptive inflation has been confirmed by InSAR (Roman et al. 2016)

1 permanent GPS station confirms no pre-eruptive inflation (Roman et al. 2016). Those results showed there was no major shallow magma storage and thus helped INETER with hazards assessment. Additionally, following those results, new GPS instruments around the volcano are being installed

Telica^a, Nicaragua

Co-eruptive deformation in 2015 confirmed by InSAR (Diana Roman, personal communication, 2017)

1 GPS station is consistent with motion observed with InSAR data

Arenal, Costa Rica

Loading and landsliding associated with recently erupted products (Muller et al. 2015)

InSAR data provided spatial covereage needed to identify process responsible for deformation, and to detect landslides on upper slopes.

Turrialba^b, Costa Rica

GPS measured deformation associated with eruptions and long-term background uplift. No major deformation in C-band and L-band interferograms. X-band data incoherent so localised deformation around vent would be undetected.

Continued ground monitoring

Poas^b, Costa Rica

GPS measured deformation associated with phreatic eruption in 2017. No background X-band acquisitions available to provide confirmation.

Continued ground monitoring

Nevado del Ruiz, Colombia^a

Broad uplift discovered centered 10 km SW of volcano (Lundgren et al. 2015)

Provided synoptic context to understand GPS data that only captured fraction of deformation

Chiles-Cerro Negro, Colombia-Ecuador

Ground deformation during seismic crisis at unmonitored volcano (Ebmeier et al. 2016)

InSAR data added to evidence from the ground observations to assess hazard

Reventador^ab, Ecuador

Topographic change associated with ongoing eruption. TanDEM-X and RSAT2 used to map 43 independent lava flows in 2012-2016 (Naranjo et al. 2016; Arnold et al. 2017)

InSAR data critical to measuring flow thickness and hence effusion rates

Tungurahua^ab, Ecuador

Also covered by GSNL. Frequent deformation on western flank detected with multiple satellites

Dense ground-based network, but deformation located between sensors (Muller 2016).

Cotopaxi^ab, Ecuador

Also covered by GSNL. Pre-eruptive deformation (Morales-Rivera et al. 2017); co-eruptive amplitude changes (Arnold et al. 2018).

Amplitude images confirmed changes in ice-cap detected by overflights. Pre-eruptive deformation detected retrospectively.

Fernandina, Ecuador

InSAR time series shows continuous uplift over the 2012-2013 period only shortly interrupted for a couple of months at the end of 2012 (Pepe et al. 2017).

Continued limited ground monitoring (1 working seismometer)

Wolf^a, Ecuador

InSAR time series shows large co-eruptive ground deformation and confirms results based on single interferograms, as in (Xu et al. 2016). No clear evidence of pre-eruptive deformation signals.

No ground monitoring, but for some seismometers on nearby islands (Bernard et al. 2015)

Auquihuato, Perú

Earthquake deformation at unmonitored volcano (Morales-Rivera et al. 2016) although no deformation observed 4/14-7/16

Ground observations planned for future

El Misti, Perú

No deformation associated with media reports of increased activity

Continued ground monitoring

Ticsani, Perú

No deformation during earthquake swarms (June-Sept. 2015)

Continued ground monitoring

Sabancaya^ab, Perú

Earthquake deformation, but no large magmatic signal (Jay et al. 2015) until potential signal in 2015-2016 (Additional file 2: Figure S2)

Combined with ground measurements during ongoing crisis

Ubinas^ab, Perú

No ground deformation measured spanning several eruptions (Additional file 2: Figure S3)

Lack of deformation is not understood

Guallatiri^b, Chile

Ground sensor detected motion but InSAR didn’t (Additional file 2: Figure S4)

Ground sensor determined to be malfunctioning

Uturuncu, Bolivia

Continued deformation detected by ground sensors but not sufficient InSAR between 2010-2014 (Henderson and Pritchard 2017)

No action

Láscar^a, Chile

Crater subsidence unaffected by VEI 1-2 eruptions (Richter et al. 2018)

Continued ground monitoring

Lazufre, Chile-Argentina

Deformation rate slowed down (Henderson et al. 2017)

Continued ground monitoring

Cerro Blanco, Argentina

Continued subsidence (López et al. 2016)

No action

Planchón-Peteroa^b, Chile

No deformation during earthquake swarm (Additional file 2: Figure S5)

Continued ground monitoring

Laguna del Maule, Chile

Uplift confirmed by ground observations (Le Mével et al. 2015; Grainger 2017)

Continued ground monitoring

Nevados de Chillán^ab, Chile

No deformation during earthquakes or explosions

Continued ground monitoring

Copahue^a, Argentina-Chile

InSAR time series show 2011-2016 inflation before summit activity (Velez et al. 2016) unaffected by several VEI 1-2 eruptions (Lundgren et al. 2017)

Continued ground monitoring

Llaima, Chile

Background observations show no deformation (Delgado et al. 2017)

Continued ground monitoring

Villarrica^ab, Chile

Deformation detected after 2015 eruption (Delgado et al. 2017)

Combined with GPS data, alert level of volcano raised

Cordón Caulle, Chile

Discovered fast uplift following eruption not detected by seismic network (Delgado et al. 2016; Euillades et al. 2017)

Deployed additional GPS receivers

Calbuco^ab, Chile

Co-eruptive but not pre-eruptive deformation (Delgado et al. 2017; Nikkhoo et al. 2017), post eruptive deformation suggested by ground sensor but not confirmed by InSAR (Additional file 2: Figure S1)

Confirmed single ground sensor had co-eruptive deformation and showed post-eruptive sensor unreliable

Chaitén, Chile

Background observations show no subsurface deformation, but topographic change at lava dome (Fig. 9e)

Continued ground monitoring

Hudson^b, Chile

Background observations show no deformation during earthquake swarm, but new CoSSC data reveal significant topographic change before 2012 (Fig. 9C)

Continued ground monitoring