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We analyzed continuous GPS data collected from 2002–2020 to characterize slow slip events (SSEs) in and near the Nicoya Peninsula, Costa Rica. These data are bisected by the 5 September 2012 Mw 7.6 earthquake. The displacement time series contain multiple signals, including plate convergence, plate interface locking, coseismic and postseismic deformation, seasonal oscillations, SSEs, and noise. GPS‐measured coseismic and postseismic displacements associated with the Mw 7.6 earthquake are modeled and removed by a step function plus multiple timescale relaxation processes with four characteristic times: 11, 94, 470, and 1,865 days. Seasonal oscillations are eliminated using a multichannel singular spectrum analysis (M‐SSA). Ten major SSEs (Mw > 6.6) are observed in the remaining time series, with a constant recurrence interval of 21.7 ± 2.6 months. SSEs occur in both shallow (~10 km) and deep (~35 km) portions of the plate interface, but the latter last longer and have larger magnitudes. There is minimum to no slow slip in the Mw 7.6 seismic rupture area and a persistent slow slip patch beneath the Nicoya Gulf entrance. Despite strong earthquake‐related stress perturbations, the inter‐SSE locking status on the megathrust is very similar between the late and early stages of the earthquake cycle and includes locked patches that ruptured in the 2012 earthquake or continue to rupture via SSEs. Some locked patches offshore south of the Nicoya Peninsula did not rupture in 2012, do not participate in SSEs, and may be indicative of supercycle behavior, that is, strain accumulation over several seismic cycles. These areas warrant heightened monitoring. Plain Language Summary: Slow slip events (SSEs) release strain energy in Earth's crust that accumulates due to plate motion and frictional locking on the boundaries between plates. SSEs are similar to earthquakes but are less damaging, since strain is released slowly, over weeks or months. We used GPS measurements with millimeter precision to study SSEs in Northwestern Costa Rica between 2002 and 2020 and compared them to the pattern of strain accumulation over the same period. We find that these events happened about every 22 months, and the repeat time is unchanged by the 5 September 2012 Mw 7.6 Costa Rica earthquake. Locking patterns also remain similar before and after this earthquake. However, some locked zones did not rupture in the 2012 earthquake or earthquakes in the last few decades and do not participate in SSEs. These areas may represent zones of higher seismic risk in the future. Key Points: Slow slip events >Mw 6.6 in northwestern Costa Rica occurred every 21.7 ± 2.6 months based on data from 33 GPS stations between 2002 to 2020Slow slip recurrence/distribution and inter‐transient strain accumulation patterns were unchanged by the 5 September 2012 Mw 7.6 earthquakeSome inter‐transient locked patches offshore did not rupture in 2012 and do not participate in slow slip events [ABSTRACT FROM AUTHOR]

Texas is experiencing increasing seismicity, likely related to the oil and gas production process. We used satellite InSAR (Interferometric Synthetic Aperture Radar) to monitor surface deformation at three study sites in western Texas with similar geologic characteristics. The deformation data were compared to earthquake distribution, groundwater changes, volumes of produced and injected fluid, and calculated pore pressure change and Coulomb failure stress change to assess causes of deformation and seismicity. Site 1 experienced surface uplift due to fluid injection but no increase in seismicity. The average media properties were estimated based on the deformation using a poroelastic model. Site 2 experienced subtle surface subsidence and elevated seismicity. Subsidence here might reflect groundwater withdrawal. Simulated pore pressure changes using MODFLOW suggest the earthquakes are likely induced by fluid injection. Site 3 experienced significant surface subsidence and seismicity. InSAR time series, water level data, and oil/gas extraction history suggest that subsidence in the northern part of this site reflects oil/gas extraction, while subsidence in the southern part is mainly due to groundwater withdrawal. An Okada tensile model was used to derive the equivalent source strength causing the subsidence, then Coulomb failure stress changes associated with this source were calculated. We found that pore pressure change (simulated using MODFLOW) due to fluid injection is likely the main contributor to elevated seismicity at this site. Variations in oil/gas production activity, seismicity, and surface deformation between our three sites suggest the importance of local rock structure and media properties in determining susceptibility to induced seismicity. Plain Language Summary: In recent years, both oil/gas production and earthquake number have increased in western Texas. This coincidence suggests at least some of the earthquakes are likely related to the oil/gas production process. We used sequential satellite images to measure surface deformation at three study sites in the Delaware Basin, western Texas. These three sites show different patterns of surface deformation and earthquake occurrence: (1) Site 1 has obvious uplift but no earthquakes; (2) Site 2 has little subsidence but many earthquakes; (3) Site 3 has significant subsidence and earthquakes. By analyzing temporal and spatial correlations between multiple independent data sets and the results of numerical models, we found the likely causes of the deformation and elevated earthquakes: (1) Surface uplift at Site 1 is due to fluid injection; (2) surface subsidence and earthquakes at Site 2 are probably related to groundwater withdrawal and fluid injection, respectively; and (3) the obvious surface subsidence at Site 3 reflects groundwater withdrawal in the south and oil/gas extraction in the north, while earthquakes are likely related to fluid injection. Since our model results rely on subsurface media properties, better assessment of whether an earthquake was or was not induced will require better knowledge of local rock properties. Key Points: Increasing numbers of earthquakes in recent years south and southeast of Pecos city, Texas, are likely related to oil and gas productionInSAR time series deformation was used to distinguish the causes of deformation and to estimate media properties and reservoir dynamicsNumerical modeling suggests that pore pressure change due to fluid injection is likely the main contributor to the abnormal earthquakes [ABSTRACT FROM AUTHOR]

Active-layer thickness (ALT) is estimated for a study area in northern Alaska's continuous-permafrost zone using satellite data from Sentinel-1 (radar) and ICESat-2 (lidar) for the period 2017 to 2022. Synthetic aperture radar (SAR) interferograms were generated using the Short Baseline Subset (SBAS) approach. Displacement time series over the thaw season (June–September) are fit well with a linear model (root mean square error (RMSE) scatter is less than 7 mm) and show maximum seasonal subsidence of 20–60 mm. ICESat-2 products were used to validate the interferometric synthetic aperture radar (InSAR) displacement time series. ALT was estimated from measured subsidence using a widely used model exploiting the volume difference between ice and water, reaching a maximum depth in our study area of 1.5 m. Estimated ALT is in good agreement with in situ and other remotely sensed data but is sensitive to assumed thaw season onset, indicating the need for reliable surface temperature data. Our results suggest the feasibility of long-term permafrost monitoring with satellite InSAR. However, the C-band (∼55 mm center wavelength) Sentinel radar is sensitive to vegetation cover and, in our studies, was not successful for similar monitoring in the heavily treed discontinuous-permafrost zone of central Alaska. [ABSTRACT FROM AUTHOR]

Influenza outbreaks are a major burden worldwide annually. While seasonal vaccines do provide protection against infection, they are limited in that they need to be updated every year to account for the constantly mutating virus. Recently, lipid nanoparticles (LNPs) encapsulating mRNA have seen major success as a vaccine platform for SARS-CoV-2. Herein, we applied LNPs to deliver an mRNA encoding a computationally optimized broadly active (COBRA) influenza immunogen. These COBRA mRNA LNPs induced a broadly active neutralizing antibody response and protection after lethal influenza challenge. To further increase the immunogenicity of the COBRA mRNA LNPs, we combined them with acetalated dextran microparticles encapsulating a STING agonist. Contrary to recent findings, the STING agonist decreased the immunogenicity of the COBRA mRNA LNPs which was likely due to a decrease in mRNA translation as shown in vitro. Overall, this work aids in future selection of adjuvants to use with mRNA LNP vaccines. [Display omitted] [ABSTRACT FROM AUTHOR]

The Eastern California shear zone in the Mojave Desert, California, accommodates nearly a quarter of Pacific–North America plate motion. In south-central Mojave, the shear zone consists of six active faults, with the central Calico fault having the fastest slip rate. However, faults to the east of the Calico fault have larger total offsets. We explain this pattern of slip rate and total offset with a model involving a crustal block (the Mojave Block) that migrates eastward relative to a shear zone at depth whose position and orientation is fixed by the Coachella segment of the San Andreas fault (SAF), southwest of the transpressive “big bend” in the SAF. Both the shear zone and the Garlock fault are assumed to be a direct result of this restraining bend, and consequent strain redistribution. The model explains several aspects of local and regional tectonics, may apply to other transpressive continental plate boundary zones, and may improve seismic hazard estimates in these zones. [ABSTRACT FROM AUTHOR]

Abstract: Hydrologically induced deformation of Earth's surface can be measured with high precision geodetic techniques, which in turn can be used to study the underlying hydrologic process. For geodetic study of other Earth processes such as tectonic and volcanic deformation, or coastal subsidence and its relation to relative sea level rise and flood risk, hydrological loading may be a source of systematic error, requiring accurate correction. Accurate estimation of the hydrologic loading deformation may require consideration of local as well as regional loading effects. We present a new hybrid approach to this problem, providing a mathematical basis for combining local (near field) and regional to global (far field) loading data with different accuracies and spatial resolutions. We use a high‐resolution hydrological model (WGHM) for the near field and GRACE data for the far field. The near field is defined as a spherical cap and its contribution is calculated using numerical evaluation of Green's functions. The far field covers the entire Earth, excluding only the near‐field cap. The far‐field contribution is calculated using a modified spherical harmonic approach. We test our method with a large GPS data set from central North America. Our new hybrid approach improves fits to GPS‐measured vertical displacements, with 25% and 35% average improvement relative to GRACE‐only or WGHM‐only spherical harmonic solutions. Our hybrid approach can be applied to a wide variety of environmental surface loading problems. [ABSTRACT FROM AUTHOR]

Ice velocity variations near the terminus of Jakobshavn Isbræ, Greenland, were observed with a terrestrial radar interferometer (TRI) during three summer campaigns in 2012, 2015, and 2016. We estimate a ~1 km wide floating zone near the calving front in early summer of 2015 and 2016, where ice moves in phase with ocean tides. Digital elevation models (DEMs) generated by the TRI show that the glacier front here was much thinner (within 1 km of the glacier front, average ice surface is ~100 and ~110m above local sea level in 2015 and 2016, respectively) than ice upstream (average ice surface is >150m above local sea level at 2-3 km to the glacier front in 2015 and 2016). However, in late summer 2012, there is no evidence of a floating ice tongue in the TRI observations. Average ice surface elevation near the glacier front was also higher, ~125m above local sea level within 1 km of the glacier front. We hypothesize that during Jakobshavn Isbræ's recent calving seasons the ice front advances ~3 km from winter to spring, forming a >1 km long floating ice tongue. During the subsequent calving season in mid- and late summer, the glacier retreats by losing its floating portion through a sequence of calving events. By late summer, the entire glacier is likely grounded. In addition to ice velocity variation driven by tides, we also observed a velocity variation in the mélange and floating ice front that is non-parallel to long-term ice flow motion. This cross-flow-line signal is in phase with the first time derivative of tidal height and is likely associated with tidal currents or bed topography. [ABSTRACT FROM AUTHOR]

Warming ocean currents are considered to be a contributing factor to the retreat of marine-terminating glaciers worldwide, but direct observations near the ice–ocean interface are challenging. We use radar intensity imagery and an iceberg tracking algorithm to produce half-hourly current maps within an imaged portion of Jökulsárlón, a proglacial lagoon in southeastern Iceland. Over our 43.5-h observation period, the lagoon has clockwise circulation with current speeds of order 3–8 cm/s and occasional strong glacier outflows of up to ∼15 cm/s. The currents driven by the glacial outflows appear to be dominantly inertial. [ABSTRACT FROM AUTHOR]

Accurate estimates of the current rate of subsidence in the Mississippi Delta (southern United States) provide a context for planning of wetland restoration and predictions of storm surge flooding. We present a comprehensive three-dimensional surface velocity field for the Mississippi Delta based on a network of 36 high-precision continuous GPS stations. We show that while the majority of the delta is relatively stable, the southern portion continues to experience high rates of subsidence (5-6 mm yr-1). Our data are consistent with long-term tide gauge records at Grand Isle, Louisiana, and several stations in Florida. The current rate of relative sea-level rise (combined effect of land subsidence and sea-level rise) along parts of the coastal delta is ~8-9 mm yr-1. Most tide gauge stations have recorded sea-level-rise acceleration after A.D. 1970. These data have implications for land reclamation and wetland restoration in the region; parts of the delta may not be viable in the long term. [ABSTRACT FROM AUTHOR]

The 5 September 2012 Mw 7.6 earthquake on the Costa Rica subduction plate boundary followed a 62-y interseismic period. High-precision GPS recorded numerous slow slip events (SSEs) in the decade leading up to the earthquake, both up-dip and down-dip of seismic rupture. Deeper SSEs were larger than shallower ones and, if characteristic of the interseismic period, release most locking down-dip of the earthquake, limiting down-dip rupture and earthquake magnitude. Shallower SSEs were smaller, accounting for some but not all interseismic locking. One SSE occurred several months before the earthquake, but changes in Mohr-Coulomb failure stress were probably too small to trigger the earthquake. Because many SSEs have occurred without subsequent rupture, their individual predictive value is limited, but taken together they released a significant amount of accumulated interseismic strain before the earthquake, effectively defining the area of subsequent seismic rupture (rupture did not occur where slow slip was common). Because earthquake magnitude depends on rupture area, this has important implications for earthquake hazard assessment. Specifically, if this behavior is representative of future earthquake cycles and other subduction zones, it implies that monitoring SSEs, including shallow up-dip events that lie offshore, could lead to accurate forecasts of earthquake magnitude and tsunami potential. [ABSTRACT FROM AUTHOR]

Determining the Earth's surface topography and deformation with interferometric synthetic aperture radar involves measurement of phase, which, for a typical coherent radar signal, can only be done modulo 2π. The cycle of ambiguity inherent in the phase measurement has to be unwrapped over all observation dimensions (e.g., azimuth, range, and time) to remove the 2π ambiguity of the phase measurements. For a time series of SAR images, useful for reducing noise in topographic applications or measuring time-varying surface deformation, the necessary steps to connect ambiguous radar phase measurements are more challenging, and the operation may be termed 3-D phase unwrapping. We describe a 3-D unwrapping approach using an extended Kalman filter. Our approach readily exploits existing information, and is robust in the presence of noise. For all tested data sets, it provides improved accuracy compared to existing approaches. [ABSTRACT FROM AUTHOR]

Hardcore, or long-term derelict and vacant brownfield sites which are often contaminated, form a significant proportion of brownfield land in many cities, not only in the UK but also in other countries. The recent economic recession has placed the economic viability of such sites in jeopardy. This paper compares the approaches for bringing back hardcore brownfield sites into use in England and Japan by focusing on ten case studies in Manchester and Osaka, using an 'agency'-based frame- work. The findings are set in the context of (i) national brownfield and related policy agendas; (ii) recent trends in land and property markets in both England and Japan; and (iii) city-level comparisons of brownfields in Manchester and Osaka. The research, which was conducted during 2009-10, suggests that hardcore brownfield sites have been badly affected by the recent recession in both Manchester and Osaka. Despite this, not only is there evidence that hardcore sites have been successfully regenerated in both cities, but also that the critical success factors (CSFs) operating in bringing sites back into use share a large degree of commonality. These CSFs include the presence of strong potential markets, seeing the recession as an opportunity, long-term vision, strong branding, strong partnerships, integrated development, and getting infrastructure into place. Finally, the paper outlines the policy implications of the research. [ABSTRACT FROM AUTHOR]

Abstract: We analyzed 23 satellite SAR (synthetic aperture radar) scenes using Persistent Scatter Interferometry (PSI) to study subsidence in Mexico City associated with groundwater withdrawal. The data were acquired by the Envisat ASAR system between January 2004 and July 2006. The spatial pattern of subsidence and the maximum subsidence rate (300mm/year) are similar to earlier studies. Comparison to independent GPS data indicates RMS agreement between the two techniques of 6.9mm/year, about the level expected based on joint data uncertainty. Significant annual variation in the GPS vertical data is not observed, suggesting minimal aquifer recharge during the rainy season, and justifying a simple linear model of phase variation through time for the PSI analysis. [Copyright &y& Elsevier]

Abstract: We present new space geodetic data indicating that the present slip rate on the Hunter Mountain–Panamint Valley fault zone in Eastern California (5.0±0.5mm/yr) is significantly faster than geologic estimates based on fault total offset and inception time. We interpret this discrepancy as evidence for an accelerating fault and propose a new model for fault initiation and evolution. In this model, fault slip rate initially increases with time; hence geologic estimates averaged over the early stages of the fault''s activity will tend to underestimate the present-day rate. The model is based on geologic data (total offset and fault initiation time) and geodetic data (present day slip rate). The model assumes a monotonic increase in slip rate with time as the fault matures and straightens. The rate increase follows a simple Rayleigh cumulative distribution. Integrating the rate-time path from fault inception to present-day gives the total fault offset. [Copyright &y& Elsevier]

Abstract: The combining of visible light and infrared visual representations occurs naturally in some creatures, including the rattlesnake. This process, and the wide-spread use of multi-spectral multi-sensor systems, has influenced research into image fusion methods. Recent advances in image fusion techniques have necessitated the creation of novel ways of assessing fused images, which have previously focused on the use of subjective quality ratings combined with computational metric assessment. Previous work has shown the need to apply a task to the assessment process; the current work continues this approach by extending the novel use of scanpath analysis. In our experiments, participants were shown two video sequences, one in high luminance (HL) and one in low luminance (LL), both featuring a group of people walking around a clearing of trees. Each participant was shown visible and infrared (IR) inputs alone; and side-by-side (SBS); in an average (AVE) fused; a discrete wavelet transform (DWT) fused; and a dual-tree complex wavelet transform (DT-CWT) fused displays. Participants were asked to track one individual in each video sequence, as well as responding by key press when other individuals carried out secondary actions. Results showed the SBS display to lead to much poorer accuracy than the other displays, while reaction times in carrying out the secondary task favoured AVE in the HL sequence and DWT in the LL sequence. Results are discussed in relation to previous findings regarding item saliency and task demands, and the potential for comparative experiments evaluating human performance when viewing fused sequences against naturally occurring fusion processes such as the rattlesnake is highlighted. [Copyright &y& Elsevier]

Since the late 1950s, several areas of Mexico City have undergone accelerated ground subsidence and have developed associated fracturing and faulting. New interferometric synthetic aperture radar (InSAR) and global positioning system (GPS) data indicate that rates of current land subsidence in Mexico City exceed 350 mm/yr. These rates are close to historical maximum levels of the mid-twentieth century, when mitigation efforts were first undertaken to reduce damage to urban infrastructure. The locus of maximum subsidence has shifted from its historical location in the old city center to the east. Correlation of our InSAR results with seismically mapped stratigraphic units suggests that subsidence is primarily controlled by compaction of Quaternary lacustrine clays and silts. We also evaluate spatial gradients in subsidence and suggest that this, rather than subsidence magnitude, is the key factor in risk assessment. Subsidence represents a major geologic risk for Mexico City and imposes serious constraints to any further urban development. [ABSTRACT FROM AUTHOR]

The property development industry is a key actor in UK brownfield regeneration projects. UK policy has attempted to interlink 'sustainable development' and 'sustainable brownfield' policy agendas, which have found an additional focus through the UK government's 'Sustainable Communities Plan', part of a growing international emphasis on sustainable development. This paper examines the emergence of these agendas and related policies, and the role of the property development industry in the regeneration of six differing brownfield sites, based in Thames Gateway and Greater Manchester. Using a conceptual framework, the paper investigates aspects of the sustainability of these projects and highlights key lessons from them for both the UK and overseas. The research is based on structured interviews with a variety of stakeholders, including developers, planners, consultants and community representatives to highlight emerging best practice and related policy implications. [ABSTRACT FROM AUTHOR]

The increased interest in image fusion (combining images of two or more modalities such as infrared and visible light radiation) has led to a need for accurate and reliable image assessment methods. Previous work has often relied upon subjective quality ratings combined with some form of computational metric analysis. However, we have shown in previous work that such methods do not correlate well with how people perform in actual tasks utilising fused images. The current study presents the novel use of an eye-tracking paradigm to record how accurately participants could track an individual in various fused video displays. Participants were asked to track a man in camouflage outfit in various input videos (visible and infrared originals, a fused average of the inputs; and two different wavelet-based fused videos) whilst also carrying out a secondary button-press task. The results were analysed in two ways, once calculating accuracy across the whole video, and by dividing the video into three time sections based on video content. Although the pattern of results depends on the analysis, the accuracy for the inputs was generally found to be significantly worse than that for the fused displays. In conclusion, both approaches have good potential as new fused video assessment methods, depending on what task is carried out. [ABSTRACT FROM AUTHOR]

Abstract: We investigate the effects of viscoelastic (VE) rheologies surrounding a vertically dipping prolate spheroid source during an active period of time-dependent deformation between 1995 and 2000 at Long Valley caldera. We model a rapid magmatic inflation episode and slip across the South Moat fault (SMF) in late 1997. We extend the spherical VE shell model of Newman et al. [Newman, A.V., Dixon, T.H., Ofoegbu, G., Dixon, J.E., 2001. Geodetic and seismic constraints on recent activity at Long Valley caldera, California: Evidence for viscoelastic rheology. J. Volcanol. Geotherm. Res. 105, 183–206.] to include a prolate spheroid geometry more accurately representing the probable source geometry inferred from other studies. This paper presents the first attempt to geodetically constrain the volcanic deformation source volume at Long Valley, a parameter for hazard assessment. Including fault slip along the SMF explains significant deformation observed with several EDM baselines and components of two continuous GPS time series. Additionally, the model explains the spatial extent of deformation observed by InSAR data covering the 1997–98 inflation episode. For the time period studied, the VE model requires modest pressure changes (maximum of 14.3 MPa) that are far lower than the overburden pressure (∼115 MPa), and less than the maximum for a purely elastic model with the same geometry and elastic strength (∼45 MPa). Thus, the inclusion of a realistic VE component significantly lowers the inferred pressures necessary to explain observed surface deformation. Though our model is non-unique, it is consistent with a broader variety of data compared to purely elastic models. Only right-lateral slip, and not dilitation, was necessary to explain offsets in EDM data near and crossing the SMF. [Copyright &y& Elsevier]

Published slip rates for the Owens Valley fault zone in eastern California based on geodetic data and elastic half-space models (57 mm/yr) are faster than longer term geologic rates (2-3 mm/yr). We use Global Positioning System data spanning the central Owens Valley, a more realistic rheological model with an elastic upper crust over a viscoelastic lower crust and upper mantle, and paleoseismic data from adjacent faults, to show that this difference could reflect earthquake-cycle effects. We estimate a long-term rate (2.1 ± 0.7 mm/yr) and earthquake recurrence interval (2750 +350/ -1000 yr) from the geodetic data, both in agreement with independent geologic estimates. [ABSTRACT FROM AUTHOR]

Describes present-day relative plate motion between the Caribbean and South America plates using Global Positioning System data. Rigidity of the Caribbean and South America plates; Comparison of angular-velocity vectors.

Presents a study on late quaternary slip rates and satellite-based geodetic data, for the western Great Basin constrain regional, California, fault-slip distribution and evolution. Geologic slip rate on the Fish Lake Valley fault zone; Faults connected to the Saline Valley fault; What the combination of geologic and geodetic data suggest.

Influenza virus outbreaks are a major burden worldwide each year. Current vaccination strategies are inadequate due to antigenic drift/shift of the virus and the elicitation of low immune responses. The use of computationally optimized broadly reactive antigen (COBRA) hemagglutinin (HA) immunogens subvert the constantly mutating viruses; however, they are poorly immunogenic on their own. To increase the immunogenicity of subunit vaccines such as this, adjuvants can be delivered with the vaccine. For example, agonists of the stimulator of interferon genes (STING) have proven efficacy as vaccine adjuvants. However, their use in high-risk populations most vulnerable to influenza virus infection has not been closely examined. Here, we utilize a vaccine platform consisting of acetalated dextran microparticles loaded with COBRA HA and the STING agonist cyclic GMP-AMP. We examine the immunogenicity of this platform in mouse models of obesity, aging, and chemotherapy-induced immunosuppression. Further, we examine vaccine efficacy in collaborative cross mice, a genetically diverse population that mimics human genetic heterogeneity. Overall, this vaccine platform had variable efficacy in these populations supporting work to better tailor adjuvants to specific populations. [ABSTRACT FROM AUTHOR]

To constrain the poroelastic component of postseismic deformation, we model the subsurface hydrologic response to the Mw 7.6 subduction zone earthquake that occurred on the plate interface beneath the Nicoya peninsula in Costa Rica on 5 September 2012. The model shows that poroelastic relaxation occurs on multiple time scales and the associated deformation can be up to 2 cm for the trench‐perpendicular component. By modeling the time‐dependent deformation associated with poroelastic relaxation, we can begin to remove its contribution from the observed geodetic signal. Inversions for after slip that ignore poroelastic deformation have errors of 10–20% overall and up to 50% locally. Poroelastic effects can both mute and amplify the inferred afterslip. Plain Language Summary: Large earthquakes can affect regional groundwater pressures. This sets up large‐scale groundwater movements that in turn lead to observable surface deformation. Accounting for these deformations is important during interpretation of GPS signals after large earthquakes. These measurements are often used to infer ongoing deformation on the fault. We show that if these calculations do not account for deformation due to groundwater flow, this can lead to errors of up to 40%. Key Points: For the Nicoya earthquake the poroelastic deformation can account for most of the postseismic deformation within 7 days at some stationsFor this earthquake, postseismic geodetic signals can be either amplified or muted by the poroelastic response, depending on locationThe poroelastic response to the Nicoya earthquake may induce error up to 40% in elastic‐only afterslip estimates [ABSTRACT FROM AUTHOR]

Whitehead, S.J.; Yeager, K.M.; Feagin, R.A.; Huff, T.P.; Paine, J.G.; Schindler, K.S., and Dixon, T.S., 2024. Growth fault–induced effects on tidal marsh surficial processes and landscape conversion in the Slop Bowl, Brazoria National Wildlife Refuge, Texas. Journal of Coastal Research, 40(1), 64–79. Charlotte (North Carolina), ISSN 0749-0208. The Slop Bowl marsh, located in the Brazoria National Wildlife Refuge on the Texas coast, is an anthropogenically influenced tidal marsh setting that has experienced rapid rates of landscape conversion and loss over the last ∼70 years. This tidal marsh has been affected by recently active faults and several hydrologic barriers (roads, pipeline channels, and active hydrocarbon-extraction well pads). Geophysical field methods and sedimentological analyses were conducted to better understand the effects of these developments on marsh surficial processes. Lithostratigraphy, shallow geophysical data, GPS surveys, radionuclide dating, and organic matter analyses all exhibited influences connected to growth-fault motion. The location and activity of a major growth fault were identified as contributing to subsidence on the downthrown fault block and causing vertical displacement of the marsh surface. Fault motion, in conjunction with the construction of roads, has disrupted the natural hydrologic pathways that once existed. Their combined effects resulted in transition of the land cover over the past several decades from a saline coastal prairie to a tidal marsh–dominant landscape, with continued future submergence anticipated. As the natural laboratory of the Slop Bowl demonstrates, anthropogenic development, neotectonics, and hydrocarbon extraction can have outsized effects on sedimentation processes, with implications for the long-term sustainability of coastal wetland environments in the northern Gulf of Mexico. [ABSTRACT FROM AUTHOR]

It has long been recognized that New Orleans is subsiding and is therefore susceptible to catastrophic flooding. Here we present a new subsidence map for the city, generated from space-based synthetic-aperture radar measurements, which reveals that parts of New Orleans underwent rapid subsidence in the three years before Hurricane Katrina struck in August 2005. One such area is next to the Mississippi River–Gulf Outlet (MRGO) canal, where levees failed during the peak storm surge: the map indicates that this weakness could be explained by subsidence of a metre or more since their construction. [ABSTRACT FROM AUTHOR]

In February 2014 a M w = 7.0 slow slip event (SSE) took place beneath the Nicoya Peninsula, Costa Rica. This event occurred 17 months after the 5 September 2012, M w = 7.6, earthquake and along the same subduction zone segment, during a period when significant postseismic deformation was ongoing. A second SSE occurred in the middle of 2015, 21 months after the 2014 SSE and 38 months after the earthquake. The recurrence interval for Nicoya SSEs was unchanged by the earthquake. However, the spatial distribution of slip for the 2014 event differed significantly from previous events, having only deep (~40 km) slip, compared to previous events, which had both deep and shallow slip. The 2015 SSE marked a return to the combination of deep plus shallow slip of preearthquake SSEs. However, slip magnitude in 2015 was nearly twice as large ( M w = 7.2) as preearthquake SSEs. We employ Coulomb Failure Stress change modeling in order to explain these changes. Stress changes associated with the earthquake and afterslip were highest near the shallow portion of the megathrust, where preearthquake SSEs had significant slip. Lower stress change occurred on the deeper parts of the plate interface, perhaps explaining why the deep (~40 km) region for SSEs remained unchanged. The large amount of shallow slip in the 2015 SSE may reflect lack of shallow slip in the prior SSE. These observations highlight the variability of aseismic strain release rates throughout the earthquake cycle. [ABSTRACT FROM AUTHOR]

The findings of the Barker review, which examined the reasons for the undersupply of UK housing, have important implications for the devolved constituents of the UK, including Scotland. This paper traces the emergence of the brownfield regeneration policy agenda across the UK and examines how the Barker review connects with this brownfield policy focus. The paper compares housing and brownfield policies and practices in England and Scotland, places them in an international context and elicits wider lessons for devolved governance in relation to housing policy, in terms of 'centrist-local' tensions. Estimates based on published data suggest that Barker's emphasis on increased housing supply cannot easily be reconciled with the current emphasis on brownfield development and is likely to require a return to greenfield development in both countries. [ABSTRACT FROM AUTHOR]

The M 6.5 earthquake that occurred in the Monte Cristo Range near Mina, Nevada on 15 May 2020 was exceptionally well-recorded with both seismic and geodetic instrumentation. The arid nature of the region also facilitated detailed ground mapping of the surface rupture. Here we integrate several independent data sets to illustrate the educational and research opportunities afforded by these rich data sets. We construct a series of models for slip at depth that are consistent with the satellite-derived geodetic data, the distribution of aftershocks, and the mapped surface rupture. We also show that the modelled depth of maximum slip is in good agreement with heat flow and laboratory data on quartz rheology defining the depth of the brittle-ductile transition. The Monte Cristo Range earthquake also suggests new approaches to seismic hazard assessment may be required for earthquakes in rapidly evolving tectonic regions such as the Walker Lane and Eastern California shear zone. [ABSTRACT FROM AUTHOR]

We investigate postseismic deformation following the 15 May 2020, Mw 6.5 Monte Cristo Range, Nevada earthquake using geodetic and aftershock data. Seven months of Sentinel 1‐A/B SAR images were used to model deformation as afterslip on two subparallel fault planes outlined by aftershocks. Postseismic deformation fits exponential and logarithmic decay models equally well. For exponential decay, the average decay time is ∼38 days. On the western plane, where most coseismic slip was observed, afterslip was minor, occurred at shallower depths than coseismic slip, and is anticorrelated with aftershock distribution. On the eastern plane, afterslip is significant, exceeds coseismic moment release, occurred at and below coseismic slip, and is correlated with aftershock distribution. On both segments, geodetic moment exceeds seismic moment, suggesting most afterslip occurred aseismically. Aseismic creep does not make up for observed coseismic shallow slip deficit, perhaps related to fault immaturity. Plain Language Summary: Monitoring surface deformation and slip at depth after an earthquake can be used to investigate changes in the local stress field caused by earthquakes and infer frictional and other conditions on earthquake‐causing faults. We used InSAR satellite data and ground‐based seismic data to study afterslip associated with a moderate magnitude earthquake in Nevada that occurred on 15 May 2020. Most energy after the mainshock was released aseismically rather than as aftershocks. The large (∼1.4 m) coseismic slip that occurred at a depth of about 8–10 km never propagated to the surface, either during or after the earthquake. Geologic estimates of motion on this fault would therefore underestimate the motion at depth, perhaps leading to underestimation of the fault's long‐term slip rate. Key Points: InSAR time series reveal that the average characteristic relaxation time for postseismic motion is ∼38 days for the Monte Cristo Range earthquakeWhile aseismic afterslip exceeded seismic afterslip, combined afterslip did not compensate for the shallow coseismic slip deficitFault immaturity might explain the shallow slip deficit and the relatively low amount of afterslip compared to coseismic slip [ABSTRACT FROM AUTHOR]

We investigate the 2007 Pisco, Peru, earthquake ( M8.0) using seismological and geodetic data. Analysis of teleseismic records indicates that the earthquake is characterized by a steadily increasing moment rate, with the maximum occurring between about 55 and 70 s and the associated slip occurring about 40 km south of the epicentre. We combine InSAR data from L-band (ALOS) and C-band (Envisat) satellites to produce a 3-D image of the ground displacements caused by the earthquake. Distributed slip inversions of the interferograms identify a single large patch of slip in the location of the maximum moment rate identified by seismology. Despite a clear spatial coincidence between the location of the coseismic slip and the anomalously high topography of the Paracas Peninsula, we find no evidence that the earthquake was directly responsible for motion on any upper plate faults. [ABSTRACT FROM AUTHOR]

While it is generally assumed that global plate motions are driven by the pattern of convection in the Earth's mantle, the details of that link remain obscure. Bouyancy forces associated with subduction of cool, dense lithosphere at zones of plate convergence are thought to provide significant driving force, but the relative magnitudes of other driving and resisting forces are less clear, as are the main factors controlling long-term changes in plate motion. The ability to consider past as well as present plate motions provides significant additional constraints, because changes in plate motion are necessarily driven by changes in one or more driving or resisting forces, which may be inferred from independent data. Here we present for the first time a model that explicitly links global mantle convection and lithosphere models to infer plate motion changes as far back as Miocene time. By accurately predicting observed convergence rates over the past 10 m.y., we demonstrate that surface topography generated at convergent margins is a key factor controlling the long-term evolution of plate motion. Specifically, the topographic load of large mountain belts and plateaus consumes a significant amount of the driving force available for plate tectonics by increasing frictional forces between downgoing and overriding plates. [ABSTRACT FROM AUTHOR]

[Display omitted] Vaccines represent a pivotal health advancement for preventing infection. However, because carrier systems with repeated administration can invoke carrier-targeted immune responses that diminish subsequent immune responses (e.g., PEG antibodies), there is a continual need to develop novel vaccine platforms. Zinc carnosine microparticles (ZnCar MPs), which are composed of a one-dimensional coordination polymer formed between carnosine and the metal ion zinc, have exhibited efficacy in inducing an immune response against influenza. However, ZnCar MPs' limited suspendability hinders clinical application. In this study, we address this issue by mixing mannan, a polysaccharide derived from yeast, with ZnCar MPs. We show that the addition of mannan increases the suspendability of this promising vaccine formulation. Additionally, since mannan is an adjuvant, we illustrate that the addition of mannan increases the antibody response and T cell response when mixed with ZnCar MPs. Mice vaccinated with mannan + OVA/ZnCar MPs had elevated serum IgG and IgG1 levels in comparison to vaccination without mannan. Moreover, in the mannan + OVA/ZnCar MPs vaccinated group, mucosal washes demonstrated increased IgG, IgG1, and IgG2c titers, and antigen recall assays showed enhanced IFN-γ production in response to MHC-I and MHC-II immunodominant peptide restimulation, compared to the vaccination without mannan. These findings suggest that the use of mannan mixed with ZnCar MPs holds potential for subunit vaccination and its improved suspendability further promotes clinical translation. [ABSTRACT FROM AUTHOR]

Estimates of flood susceptibility and land loss in the world's coastal regions depend on our knowledge of sea level rise (SLR) from increases in ocean mass and volume, as well as knowledge of vertical land motion. Conventional approaches to the latter include tide‐gauge and Global Positioning System (GPS) measurements relative to well‐anchored monuments few meters below the surface. However, in regions of rapid Holocene sedimentation, compaction of this material can add a significant component to the surface lowering. Unfortunately, this process has been difficult to quantify, especially for the shallowest material above the monument. Here we use a new technique, GPS interferometric reflectometry, to estimate the rate of this process in the Mississippi Delta and the eastern margin of the North Sea. We show that the rate of shallow compaction is comparable to or larger than the rate of global SLR, adding 35% and 65%, respectively, to the rate of relative SLR by 2100. Plain Language Summary: Sea level change is influenced by vertical motion of the sea surface as well as vertical motion of the land in coastal areas. Tide gauges and GPS are two conventional approaches to measure coastal vertical land motion (VLM). GPS conventional positioning determines the vertical component of position changes resulting from displacements beneath the monument foundation. However, quantifying shallow VLM that occur above the base of monument has not been possible so far. In regions of rapid Holocene age (roughly 11,500 yr before present) sedimentation such as river deltas and coastal alluvial plains, compaction of this material, if not countered by ongoing sedimentation, can add a significant component to the rate of coastal subsidence. Here, we use a new technique, GPS interferometric reflectometry, to estimate the rate of shallow VLM in two coastal regions with thick Holocene deposits, the Mississippi Delta and the eastern margin of the North Sea. We show that the rate of VLM from shallow compaction is comparable to or larger than the rate of sea level rise. Since many of the world's great coastal cities are built on river deltas with comparable Holocene sections, our results suggest that estimates of flood risk and land loss have been underestimated. Key Points: Shallow displacement within the layer between the surface and the base of a GPS monument are measured using the GPS‐IR techniqueRates of shallow sediment compaction (SSC) are quantified at GPS sites in two coastal regions with thick and compressible Holocene depositsSSC amplifies rates of SLR in the Mississippi Delta and the east coast of the North Sea adding 35% and 65%, respectively, to SLR rates by 2100 [ABSTRACT FROM AUTHOR]

Measuring seafloor motion in shallow coastal water is challenging due to strong and highly variable oceanographic effects. Such measurements are potentially useful for monitoring near‐shore coastal subsidence, subsidence due to petroleum withdrawal, strain accumulation/release processes in subduction zones and submerged volcanoes, and certain freshwater applications, such as volcano deformation in caldera‐hosted lakes. We have developed a seafloor geodesy system for this environment based on an anchored spar buoy topped by high‐precision GPS. Orientation of the buoy is measured using a digital compass that provides heading, pitch, and roll information. The combined orientation and GPS tracking data are used to recover the three‐dimensional position of the seafloor marker (anchor). A test system has been deployed in Tampa Bay, Florida, for over 1 year and has weathered several major storms without incident. Even in the presence of strong tidal currents which can deflect the top of the buoy several meters from vertical, daily repeatability in the corrected three‐component position estimates for the anchor is 1–2 cm or better. Plain Language Summary: To measure seafloor motion in shallow water, we built a spar buoy and put a GPS antenna and a digital compass (three‐dimensional orientation sensor) on top of it. The buoy rests on the sea bottom using a heavy concrete ballast. Rotation and other movements of the buoy are measured by the digital compass and GPS. Position of the ballast can be calculated based on these measurements. We tested the system in Tampa Bay, Florida, and found that it is able to measure motion of the anchor with an uncertainty of 1–2 cm or smaller. Key Points: A GPS‐buoy system has been designed, built, and tested to measure seafloor motion in shallow waterGPS and buoy orientation measured by a digital compass enable the anchor position and effects of water motion to be accurately determinedDaily repeatability of seafloor positioning is ~1–2 cm for horizontal components and better than 1 cm for the vertical component [ABSTRACT FROM AUTHOR]

Accurate estimation of fault slip rate is fundamental to seismic hazard assessment. Previous work suggested a discrepancy between short-term geodetic and long-term geologic slip rates in the Mojave Desert section of the Eastern California Shear Zone (ECSZ). Understanding the origin of this discrepancy can improve understanding of earthquake hazard and fault evolution. We measured offsets in alluvial fans along the Calico Fault near Newberry Springs, California, and used several techniques to date the offset landforms and determine a slip rate. Our preferred slip rate estimate is 3.2 ± 0.4 mm/yr, representing an average over the last few hundred thousand years, faster than previous estimates. Seismic hazard associated with this fault may therefore be higher than previously assumed. We discuss possible biases in the various slip rate estimates and discuss possible reasons for the rate discrepancy. We suggest that the ECSZ discrepancy is an artefact of limited data, and represents a combination of faster slip on the Calico Fault, off-fault deformation, unmapped fault strands, and uncertainties in the geologic rates that have been underestimated. Assuming our new rate estimate is correct and a fair amount (40%) of off-fault deformation occurs on major ECSZ faults, the summed geologic rate estimate across the Mojave section of the ECSZ is 10.5 ± 3.1 mm/yr, which is equivalent within uncertainties to the geodetic rate estimate. [ABSTRACT FROM AUTHOR]

Retrogressive slumping could accelerate sea-level rise if ice-sheet retreat generates ice cliffs much taller than observed today. The tallest ice cliffs, which extend roughly 100 m above sea level, calve only after ice-flow processes thin the ice to near flotation. Above some ice-cliff height limit, the stress state in ice will satisfy the material-failure criterion, resulting in faster brittle failure. New terrestrial radar data from Helheim Glacier, Greenland, suggest that taller subaerial cliffs are prone to failure by slumping, unloading submarine ice to allow buoyancy-driven full-thickness calving. Full-Stokes diagnostic modeling shows that the threshold cliff height for slumping is likely slightly above 100 m in many cases, and roughly twice that (145-285 m) in mechanically competent ice under well-drained or low-melt conditions. [ABSTRACT FROM AUTHOR]

Calving of glacial ice into the ocean from the Greenland Ice Sheet is an important component of global sea level rise. The calving process itself is relatively poorly observed, understood, and modeled; as such, it represents a bottleneck in improving future global sea level estimates in climate models. We organized a pilot project to observe the calving process at Helheim Glacier in East Greenland in an effort to better understand it. During an intensive one-week survey, we deployed a suite of instrumentation including a terrestrial radar interferometer, GPS receivers, seismometers, tsunameters, and an automated weather station. This effort captured a calving process and measured various glaciological, oceanographic, and atmospheric parameters before, during, and after the event. One outcome of our observations is evidence that the calving process actually consists of a number of discrete events, spread out over time, in this instance over at least two days. This time span has implications for models of the process. Realistic projections of future global sea level will depend on accurate parametrization of calving, which will require more sustained observations. [ABSTRACT FROM AUTHOR]

We use Envisat 2003–2010 InSAR imagery over Yangzhuoyong Lake in southeastern Tibet to study the elastic response of the Earth's crust to variations in lake level. The net lake level drop during our study period is ∼3 m with seasonal variations of more than 1 m. The time-series close to the lake center shows a high correlation with the lake level history. Near the lake center the unit response with respect to lake level change is 2.5 mm/m in radar line-of-sight direction, or ∼2.7 mm/yr in vertical direction, corresponding to a vertical response of ∼4.3 mm/Gt load change. We show that the observations are most sensitive to the elastic properties of the crust in the 5–15 km depth range and explain them with a layered elastic half-space model with a Young's modulus of 50 ± 9 GPa Young's modulus in the top 15 km of the crust and using moduli inferred from seismology at greater depth. The inferred Young's modulus is ∼25% smaller than the seismic modulus, which we attribute to damaged rock and the presence of fluids. [ABSTRACT FROM AUTHOR]

The Nicoya Peninsula in Costa Rica is one of the few places on Earth where the seismically active plate interface of a subduction zone is directly overlaid by land rather than ocean. At this plate interface, large megathrust earthquakes with magnitudes greater than 7 occur approximately every 50 years. Such quakes occurred in 1853, 1900 and 1950, so another large earthquake had been anticipated. Land-based Global Positioning System (GPS) and seismic measurements revealed a region where the plate interface was locked and hence accumulated seismic strain that could be released in future earthquakes. On 5 September 2012, the long-anticipated Nicoya earthquake occurred in the heart of the previously identified locked patch. Here we report observations of coseismic deformation from GPS and geomorphic data along the Nicoya Peninsula and show that the magnitude 7.6 Nicoya earthquake ruptured the lateral and down-dip extent of the previously locked region of the plate interface. We also identify a previously locked part of the plate interface, located immediately offshore, that may not have slipped during the 2012 earthquake, where monitoring should continue. By pairing observations of the spatial extent of interseismic locking and subsequent coseismic rupture, we demonstrate the use of detailed near-field geodetic investigations during the late interseismic period for identifying future earthquake potential. [ABSTRACT FROM AUTHOR]

Interferometric synthetic aperture radar (InSAR) observations of wetlands reveal spatially detailed measurements of water-level changes and quantitative images of flow dynamics. However, lateral variability of wetland vegetation results in a heterogeneous scattering medium, which can affect interferometric coherence levels and can even limit the applicability of the technique. Here, we analyze coherence variations in Southern Florida, which consist of various wetland vegetation types, including sawgrass, graminoid, cypress, mixed shrubs, and mangrove marsh. We use JERS-1, ERS-1/2, ENVISAT, and RADARSAT-1 data, to investigate the effect of acquisition parameters and temporal baseline (time span between acquisitions) on the coherence level in the various wetland vegetation environments. The main findings of our coherence analysis are as follows: 1) Woody wetlands, such as cypress and mixed shrubs swamps, have higher coherence levels than herbaceous wetlands of sawgrass and graminoid (cattail) in all SAR data types; 2) the coherence level of C-band data is strongly dependent on temporal baseline, whereas the coherence level of L-band data depends mainly on perpendicular baseline, but to some degree also on temporal baseline; 3) backscatter from JERS-1 and RADARSAT-1 is correlated with coherence in four wetland vegetation types (sawgrass, cypress, mixed shrubs, and mangrove), but ERS backscatter has no relation to coherence, except over sawgrass marsh. Finally, our study clearly indicates that high resolution, HH polarization, and small incidence angle observations are most suitable for wetland InSAR applications. [ABSTRACT FROM AUTHOR]

Abstract: Twenty three ENVISAT Synthetic Aperture Radar (SAR) images acquired in 2003–2010 were processed with conventional SAR Interferometry (InSAR) and Persistent Scatterer Interferometry techniques, to investigate spatial and temporal patterns of land subsidence in Morelia, Mexico. Subsiding areas are distributed as either concentrated circular patterns corresponding to intense groundwater extraction (e.g., Rio Grande meander area; maximum deformation of 7–8cm/yr) or as elongate patterns oriented along NE–SW or E–W directions and parallel to major faults (i.e. La Colina, La Paloma and Central Camionera; maximum deformation of 4–5cm/yr). High subsidence rates are also measured on the hanging wall of major normal faults, where the thickest sequences of compressible Quaternary sediments crop out. Strong contrasts in subsidence rates are identified across major faults, suggesting that these faults act as barriers to horizontal movement of groundwater. Subsidence rates show a weak positive correlation with the total thickness of compressible deposits, while there is no correlation with either water extraction rates or changes in static water level. Time-lapse analysis of ground deformation with conventional InSAR reveals temporal variations of subsidence north of the La Colina fault and the Rio Grande meander area. For this latter area, cross sections and 3D perspectives of InSAR measures, and analysis of subsidence rates through time, show an acceleration of subsidence velocities since 2005, corresponding to recasing of the Prados Verdes II well, whose location is centered in the area of highest subsidence. [Copyright &y& Elsevier]

Abstract: The Carrizo segment of the San Andreas Fault separates rocks of the Salinian Block southwest of the fault characterized by high heat flow (~75–95mW/m2) and shallow seismicity (<~10km depth), from rocks of the Franciscan Complex and Great Valley Group northeast of the fault associated with low heat flow (50–60mW/m2) and deeper seismicity (<~20km depth). GPS data from this region suggest that the northeast side of the fault accommodates more interseismic strain than the southwest side. We show that by incorporating variations in depth to the brittle ductile transition inferred based on heat flow and seismicity data, we fit the geodetic data well and achieve agreement with geologically accepted long-term average slip rates with a ~20km wide zone with low Young''s modulus NE of the fault. This wide compliant zone is consistent with observations suggesting that the presence of large overpressures may be decreasing the elastic moduli in this region. [Copyright &y& Elsevier]

In the early stages of continental rifting, extension takes place by normal faulting, while in mature continental rifts dyke intrusion dominates. Little is known about the nature of the transition between fault-controlled and dyke-controlled extension or about the processes in an intermediate setting. Here, we present observations of the temporal and spatial evolution of surface displacements during the 2007 July 14–August 4 rifting episode in Northern Tanzania, an immature section of the East African Rift. The ground deformation initiated with subsidence that can be attributed to ∼40 cm of normal motion on a NE striking fault. Following July 17, deformation was dominated by the intrusion of ∼7-km-long dyke. Dyke opening increased gradually to a total of ∼2.4 m. From July 21, the collapse of a shallow graben above the fault dominated the near-field displacements. Comparison to the 2007 Dabbahu dyke, Afar, which occurred in a more mature rift, shows an order-of-magnitude scale difference in dyke length. Using numerical models of dyke propagation, we attribute this to the size and depth of the magma chamber; in immature rifts the thick crust and slow spreading rate favour small, deep magma chambers, forming short, buried dykes, whereas in mature rifts the thinner crust and faster spreading rate favour large, shallow magma chambers and long, erupting dykes. Observing the pattern of active processes in the East African Rift is key to understanding the development of rift systems and passive margins elsewhere. [ABSTRACT FROM AUTHOR]

Interferometric processing of JERS-1 L-band Synthetic Aperture Radar (SAR) data acquired over south Florida during 1993–1996 reveals detectable surface changes in the Everglades wetlands. Although our study is limited to south Florida it has implication for other large-scale wetlands, because south Florida wetlands have diverse vegetation types and both managed and natural flow environments. Our analysis reveals that interferometric coherence level is sensitive to wetland vegetation type and to the interferogram time span. Interferograms with time spans less than six months maintain phase observations for all wetland types, allowing characterization of water level changes in different wetland environments. The most noticeable changes occur between the managed and the natural flow wetlands. In the managed wetlands, fringes are organized, follow patterns related to some of the managed water control structures and have high fringe-rate. In the natural flow areas, fringes are irregular and have a low fringe-rate. The high fringe rate in managed areas reflects dynamic water topography caused by high flow rate due to gate operation. Although this organized fringe pattern is not characteristic of most large-scale wetlands, the high level of water level change enables accurate estimation of the wetland InSAR technique, which lies in the range of 5–10 cm. The irregular and low rate fringe pattern in the natural flow area reflects uninterrupted flow that diffuses water efficiently and evenly. Most of the interferograms in the natural flow area show an elongated fringe located along the transitional zone between salt- and fresh-water wetlands, reflecting water level changes due to ocean tides. [Copyright &y& Elsevier]