Long period magnetotelluric (MT) data is being collected as a component of the USArray covering the continent of North America at a quasi-regular grid. Data from 250 MT stations were acquired covering the north-western part of the United States of America (USA). Dimensionality analysis was applied using Swift skew, Bahr skew and ellipticity. Results show a 1-D/2-D character for the short periods (< 1 sec) for the shallower structures, while the longer periods (> 1 sec) shows a 3-D character for the deeper structures. Two dimensional Occam inversion was applied for a set of E-W trending profiles to map the regional electrical resistivity distribution to a depth up to crust/mantle transition zone. 2-D resistivity structures were obtained by inverting both the transverse electric (TM) and transverse magnetic (TM) modes. Results show a resistive upper crust with a decreasing resistivity for lower crust. To the west, the subudcting Gorda plate was mapped as a relatively higher resistivity body nearly equal to the Wyoming basin to the east. Thick resistive lithosphere was mapped under Wyoming to the east. The results of this research shows the distribution of the electrical resistivity with adequate details for the shallow depth, while 3D inversion is necessary for the larger depths.

The fragility of human life has been tragically demonstrated through history by numerous natural hazards (e.g. earthquakes, tsunami, drought, floods, volcanic eruptions and landslides) leading in some cases to large-scale disasters. Given that the natural processes that underpin such hazards will continue into the foreseeable future, there is widespread international agreement about the need to focus on reducing risk and increasing resilience. In line with such objectives, Indigenous knowledge (IK) in Disaster Risk Reduction (DRR) is increasingly being recognised as an alternative domain of understanding and knowing, that is highly relevant to present-day societal challenges such as natural hazards and disasters. In Aotearoa-New Zealand, rapid social, political and environmental changes have led a growing chorus of Māori leaders expressing the need to have their perspectives and histories surrounding diverse natural hazards and risk heard. Some of the contributions that Māori knowledge can make to the management and mitigation of natural hazards in Aotearoa-New Zealand have already been identified, but much remains to be done before plural knowledge learning and development can take place. In this presentation we will explore some of the benefits of epistemological and empirical differences in knowledge about natural hazards, and consider how scientific and Māori complexes of knowing and being can inform one another to contribute to effective DRR and Recovery.

NASA’s future missions will focus on looking for evidence of life under extreme environments, such as cold arid planets (Mars) and icy moons (Eurpoa). There is particular interest in studying localized geo-chemical systems that host gradients with the potential for harboring evidence of past or present life. Such gradient-driven systems include, for example, layering of minerals of varying oxidation states in the Martian subsurface or in Earth’s seafloor sediments; chemical precipitates separating fluids of different pH or Eh such as in a hydrothermal vent; or radiation-induced oxidant production in planetary ices. A challenge is that these simulated precipitates are redox sensitive and evolve over a relatively short lifetime (1-4 hrs) necessitating viable in-situ, non-destructive analytical techniques. Promising techniques for such studies are electrochemical methods, which are particularly suited for characterizing interfaces and chem-ical gradients. Combined with recent advances in electrochemical instrument technologies, new methods have been developed toward integrating portable, electrochemical systems for ex-situ and/or in-situ chemical characterization. JPL has already made significant progress in developing these new technologies, particularly electro-chemical impedance spectroscopies (EIS) for in-situ characterization of geochemical materials (i.e., soils ice mineralogy, and brines) and even life detection sensoring. Currently, we are exploring further appli-cations of electrical spectroscopy techniques in developing an electrochemistry-based framework using planetary analog systems based on MRO/CRISM and Cassini/INMS observations in attempts to distin-guish abiotic vs biotic environments, and with active and inactive containing organics from electrical properties characterization. We will highlight some of our group’s successes and preliminary results of geochemical experimentation using various electrochemical techniques.

Irrigation parameterizations in land surface models have been advanced over the past decade, but the newly available data from the Soil Moisture Active Passive (SMAP) satellite has seldom been used to improve irrigation modeling. Here, we investigate the potential of assimilating SMAP soil moisture (SM) data into the Community Land Model (CLM) to improve irrigation representation. Simulations are conducted at 3 arc-minute resolution over the highly irrigated region in the central US, fully enclosing the upstream areas of the river basins draining over the High Plains Aquifer (i.e., the Missouri and Arkansas), and Colorado River basins. We test the original CLM4.5 irrigation scheme and two new irrigation parameterizations using SMAP data assimilation by: (1) directly integrating raw SMAP data, and (2) integrating SMAP data using 1-D Kalman Filter (KF) smoother. An a priori scaling approach is also used to account for bias correction of the shortly-recorded SMAP data based on the ground observations, enabling us to use SMAP for out-of-sample tests (i.e., assessment of the new parameterizations during a non-SMAP period). The ground-based SM observations from three monitoring networks, namely Soil Climate Analysis Network (SCAN), US Climate Reference Network (USCRN), and SNOwpack TELemetry (SNOTEL) are employed for bias correcting SMAP data and validating SM simulations. Results show that SMAP data assimilation using 1-D KF significantly improves irrigation simulations. Bias correction of SMAP data further improves results from KF assimilation in some regions. However, the improvements are small compared to those achieved from 1-D KF application alone, indicating the robustness of using SMAP data and KF globally even for the regions where ground-based data are not available for bias correction. The data assimilation also improves the accuracy of the temporal dynamics and vertical profile of simulated SM. These results are expected to provide a basis for improved modeling of irrigation water use and land-atmosphere interactions.

We propose a new numerical code based on a new multi-species theoretical model to study the mass, momentum and energy exchanges (MMEE) that happen across the magnetospheric boundaries. We use two distinct populations for ions, one cold and one hot (plus one neutralising electron population), to take into account the differences between the properties of the plasmas coming from the magnetosphere and from the solar wind. This approach represents a step forward in the context of the study of coupled large-scale plasma systems being a new and efficient compromise between fluid and kinetic codes in tracing the different plasma contributions during MMEE. Due to the very important role that magnetic reconnection plays in connecting the shocked Solar Wind to the Earth’s magnetosphere, we show and discuss the results we obtained about the simulations of the tearing mode instability occurring across an Earth’s magnetopause that we modelled thanks to our most recents MMS observations [Rezeau 2018]. Rezeau, Belmont, Manuzzo, Aunai, Dargent, 2018, Journal of Geophysical Research: Space Physics, 123, doi: 10.1002/2017JA024526.

Data quality is only one of many uncertainties involved in our attempt to understand, model and predict complex nonlinear systems and to identify the properties emerging from them. Perhaps not surprisingly, less than half of published scientific studies can be successfully reproduced, with the earth sciences occupying an intermediate position among the major disciplines. The uncertainty of data quality is only one factor that contributes to the relatively poor reproducibility of research studies and the resulting hypotheses. Potentially more important factors include unsuitably low thresholds for assessing statistical relevance, inappropriate data manipulation, inadequate research design, and outright fraud. Data quality for earth science data can be communicated via measurement errors (e.g., instrument accuracy, technician practices) and addressed by employing measurement quality codes, whereas the other aforementioned factors can be identified or controlled through rigor, methods selection and research competency. A more difficult source of uncertainty includes biases, assumptions, and environmental or social influences that affect the judgment and perceptions of scientists themselves. The difficulty is that many of these factors operate beyond one’s awareness or control, residing within automatic processes of the human brain. From continually seeking, interpreting and projecting patterns (spatial and temporal) to confabulating answers and relying on heuristics, we are largely at the mercy of what the brain has evolved to do, which is not necessarily to accurately perceive the natural world. Peer reviews, precision instruments, mathematical abstractions and digital computers certainly assist us in probing nature; nevertheless, we ultimately perceive the world as we are, rather than as it is. Consequently, a scientifically “objective” view of nature is being questioned in research ranging from quantum mechanics to human consciousness. To what extent are the peculiarities of human brain responsible for the uncertainty and nuances that we believe exist in nature? Are scientists fooled by a brain that constructs, rather than simply observes, the world around us? If so, do we have the tools to deal with this kind of uncertainty?

The ionospheric modification experiments are providing the means for understanding mechanisms and physical processes leading to the generation and evolution of ionospheric irregularities. We present experimental results concentrating on the features and evolution, generation conditions and mechanisms of small-scale field-aligned irregularities (FAIs) in the high latitude ionosphere F region induced by the controlled injection of the powerful HF radio waves from the ground into the ionosphere. Experiments have been carried out at the EISCAT HF Heating facility near Tromsø, Norway, at heater frequencies of 4.5 – 8.0 MHz with an effective radiated power of 200 – 750 MW. HF pump wave with ordinary (O-mode) or extraordinary (X-mode) polarization was injected along the magnetic field-aligned direction. Instrument diagnostics included the CUTLASS (Co-operative UK Twin Located Auroral Sounding System) radar, the European Incoherent Scatter (EISCAT) UHF radar at 931 MHz near Tromsø and the EISCAT ionosonde (dynasonde). It was found that the features and physical driving mechanisms of FAIs with the spatial scale across the geomagnetic field of 7.5 – 15 m are significantly different for O- and X-mode HF pumping, presenting challenges for understanding the relevant processes. The main attention is paid to the recently discovered X-mode FAIs. By a contrast to the O-mode FAIs excited by a thermal parametric (resonance) instability at the upper hybrid resonance altitude, the X-mode FAIs are generated via two-step process. In the first step the generation of elongated large-scale irregularities (with the spatial scale across the geomagnetic field of the order of 1 -10 km depending on the background geophysical conditions and the pump frequency) is occurred. As a second step, we suggest that the filamentation instability can be responsible for the generation of small-scale FAIs. As is found from EISCAT UHF radar measurements FAIs greatly impact on the development of strong artificial turbulence such as Langmuir and ion-acoustic plasma waves.

A newly developed physics-based earthquake simulation algorithm was applied to a seismogenic model in the Central Apennines Region. This model was derived from the last version of the Database of the Individual Seismogenic Sources (DISS), from which 54 seismogenic faults have been recognized. This simulator allowed the compilation of a synthetic seismic catalog lasting 100,000 years, and containing more than 300,000 events of 4.0

There are many ethical issues that come up in geoscience research, and here I use my own experience to illustrate two of them. Ethics, unlike science, is based on values and not testable hypotheses. My values include justice and sustainability for all rather than increasing wealth for a few. One of the most important ethical issues is choosing what topics to research. In 1982 when I first heard about nuclear winter, I started work in that area. Soon thereafter, Presidents Reagan and Gorbachev ended the nuclear arms race, informed by matching scientific results from both US and Russian scientists. I continue to work in this area, because the greatest threat we pose to ourselves remains nuclear war, and the world still has enough weapons to produce nuclear winter. I think the second greatest threat is global warming. I do research on proposed interventions such as creating a cloud in the stratosphere to mimic large volcanic eruptions, which, if it proves to be technically feasible, could reduce some of the impacts of global warming. But this technique, sometimes called solar radiation management (SRM), would come with many risks. I have been working in this area for the past decade to try to better understand the potential benefits and risks, so that society, if it is tempted to consider SRM in the future, will be able to make an informed decision. I continue to work on the impacts of volcanic eruptions on climate, so we can better separate natural from anthropogenic impacts on climate, and so that we can have better seasonal forecasts after the next large eruption. I have stopped working on soil moisture, as I do not find it as ethically compelling, and I only have time for so many topics. Another ethical issue is whether to communicate policy recommendations. If you are seen to advocate a particular policy, will it tarnish your reputation as a scientist? I say, as long as you make your values clear, who better to make policy recommendations? You are the most knowledgeable on the subject. So I say that the US needs to sign the 2017 UN Treaty on the Prohibition of Nuclear Weapons, to save us and the world from nuclear annihilation. I say that the US needs to get back into the Paris Accords and increase our pledge to rapidly eliminate our greenhouse gas emissions, to save us and the world from environmental catastrophe. This is the behavior of an ethical scientist.

We couple short-term (i.e. the co-seismic) and long-term (i.e. the inter-seismic) phase of an earthquake, in order to investigate how induced static stress changes during the co-seismic phase of an earthquake cycle influence the dynamics of strain accumulation during the inter-seismic phase. We perform dynamic rupture simulations on complex strike slip faults in 2D, incorporating off-fault plastic failure and strong dynamic weakening on the fault governed by the slip weakening law. Our strike slip fault has a self-similar fractal profile with RMS height taken from observational studies. Our dynamic rupture simulation results show that the stresses in the region surrounding the fault are highly complex and heterogeneous. This heterogeneity in stresses is mainly related to roughness of fault profile and at distances where fault roughness effects are not dominant, the stresses are mostly uniform. We extract these complex stresses together with the plastic deformation from the dynamic model and use them as the input to run the long-term tectonic model (LTM). This provides us insight into the dynamics of off-fault plastic deformation in the loading phase of an earthquake. Our LTM results show that most of the shear zones (i.e. new features e.g. fractures and faults) develop and grow at oblique angles to the main fault while considerable amount of damage keeps accumulating along the immediate sides of the fault profile. The development and growth of these new features occurs in the locations where geometrical bends in the fault profile has caused the deformation in the dynamic phase to be localized. This localized deformation due to fault roughness acts as a seed for the development of new features. We conclude that the complex damage pattern in the fault damage zones (observed in observational studies) is mainly due to the fault surface roughness effects. During the co-seismic phase, the stresses concentrate near the fault bends due to rough fault profile. During the inter-seismic phase, these locations are favored for the development of new features during the inter-seismic phase the earthquake.

We present preliminary results from an electrokinetic laboratory rock characterization approach, which uses electroosmosis and streaming potential to estimate permeability. The device has two modes. In its first mode it measures differential pressure across a sample while applying electric current or acoustic pressure, while in its second mode it measures voltage across the sample when applying electric current or acoustic pressure. The two modes result in estimates of the electrokinetic coupling coefficients, which can jointly be used to estimate the permeability of the sample. Our collaboration includes analytical and numerical approaches simulating aspects of the experiments being carried out in the laboratory at Sandia. Sandia National Laboratories is a multimission laboratory managed and operated by National Technology & Engineering Solutions of Sandia, LLC, a wholly owned subsidiary of Honeywell International Inc., for the U.S. Department of Energy’s National Nuclear Security Administration under contract DE-NA0003525.

Accurate and seamless coastal water level observations are crucial for monitoring climate change, mean sea level, and storm surge. Although the water level changes have been measured using local measurement instruments at coastal sites for centuries, the spatial distribution of these sites is typically limited to locations with infrastructure. For example, Alaska has significant gaps in the spatially varying tidal information so that more supports are needed for coastal mapping and storm surge preparedness. GNSS-Reflectometry (GNSS-R) is being investigated as tool for water level monitoring. By calculating the phase delay of the GNSS radio signals reflected by the water surface, the temporal variation of the water level can be observed. The advantage of this system is twofold: 1) It is non-contact and measures water levels as it is based on remote sensing technique. 2) resulting water level measurements are tied directly to a global reference frame that it significantly contributes to the consistent vertical datum. In this study, we processed data from three Continuously Operating Reference Stations in California (CACC), Louisiana (CALC), and Alaska (AT01), which are operated by NGS and UNAVCO. The resulting water levels were compared with observations from stations in the NOAA’s National Water Level Observation Network (NWLON). The CALC station was selected specifically for performance evaluation during hurricane Harvey. The GNSS-R results show a strong agreement with the published observations and datums from the NWLON stations. The peak storm surge induced by hurricane Harvey is clearly observed in the data from CALC. Tidal datums computed from CALC data are within 6cm of published. Data from the AT01, located in St. Michael Alaska, show tidal characteristics not represented in the published predictions, which are based on data collected between 1891 and 1899. The AC01 results are very encouraging considering the expected challenges due to limited GNSS observations and strong ionospheric activities in high latitudes. The results from this study show many promising applications for GNSS-R derived water levels, such as tidal datum determination, predictions and validation of vertical datum separation models.

Thousands of exoplanets have been discovered in last two decades, including a sample of rocky worlds in the habitable zones of their host stars. Assessing their habitability will rely on the observation and characterization of atmospheres of these distant worlds. Laboratory simulations can provide critical information for atmospheric observations of exoplanets. Thus, we conducted a series of laboratory experiments that simulated a broad range of atmospheres in cooler (<800 K), smaller (<0.3× Jupiter’s mass) exoplanets. We investigated three types of atmospheric metallicities, 100× solar (H2-dominated), 1,000× (H2O-dominated), and 10,000× (CO2-dominated) at three temperatures, 300, 400, and 600 K using the PHAZER (Planetary Haze Research) chamber at Johns Hopkins University (He et al. 2017) with one of two energy sources (AC glow plasma and UV photons). We find that all simulated atmospheres resulted in haze formation with both energy sources, but the production rates vary a lot with different conditions (He et al. 2018a, 2018b; Hörst et al. 2018). The resulting haze particles can affect the atmospheric and surface temperature of the exoplanets, and their potential habitability. We monitored the gas phase compositional changes with a quadrupole mass spectrometry during the experiments and characterized the resulted haze particles. We find that the organic molecules are produced in both gas and solid phases, which could provide a source of organic material to the surface for life to arise. We identified potential precursors (C2H2, HCN, CH2NH, HCHO, etc.) for haze formation, among which HCHO and HCN are also important prebiotic precursors for products of biological significance (sugars, amino acids, and nucleobases). The laboratory results increase our understanding the habitability of exoplanets and can help guide and interpret current and future atmospheric observations of exoplanets. Ref: He, C., Hörst, S. M., et al. 2017, APJL, 841, L31 He, C., Hörst, S. M., Lewis, N. K., et al. 2018, ApJL, 856, L3 He, C., Hörst, S. M., Lewis, N. K., et al. 2018, AJ, 156, 38 Hörst, S. M., He, C., Lewis, N. K., et al. 2018, Nat. Astron., 2, 303

For youth with limited role models in the STEM fields, and restricted summer research opportunities resulting from a lack of financial resources and academic connections, the opportunity to participate in academically connected, community based science research programs can be incredibly empowering. Providing these opportunities is critically important but it takes purposeful work, persistent outreach and strong community networks. We note that while providing these opportunities is incredibly rewarding, but there is a lot of work both up front and ongoing. This work is itself rewarding when networks are humming and enthusiasm for involvement is high, but it can be challenging when ceilings are hit and walls seem to arise unexpectedly. “Early Engagement in Research: Broadening participation through engagement in authentic science research” builds a regional network of summer research experiences for high school students underrepresented in STEM, starting from a successful model that has provided high school summer field research opportunities for New York City youth for over a decade (Secondary School Field Research Program). The program is developed around regional partnerships between various combinations of academic institutions and research centers, community environmental and education centers, state cooperative extensions, high schools and school networks, state and local park systems and land management groups. Each location has a unique approach, but all include some similar attributes. Each tackles an authentic science research issue that affects the local community such as microbiology in the local streams and microplastics in the local bays and biology, and each includes peer and near peer mentoring for the students along with a scientist mentor. Encouraging professional development of each student is central to the program. Technical instruction includes the use of scientific instruments and equipment, data recording and interpretation. Professional discussions include how to successfully read and dissect a science journal article, how to create and present a science poster and most importantly how build a network for themselves in STEM, and how to help us work with them to support the diversity that is needed for all of science to be inclusive and ultimately meet the needs of our future.

We perform numerical simulations of the TRAPPIST-1 system of seven exoplanets orbiting a nearby M dwarf, starting with a previously suggested stable configuration. The long-term stability of this configuration is confirmed, but the motion of planets is found to be chaotic. The eccentricity values are found to vary within finite ranges. The rates of tidal dissipation and tidal evolution of orbits are estimated, assuming an Earth-like rheology for the planets. We find that under this assumption, the planets b, d, and e were captured in the 3:2 or higher spin–orbit resonances during the initial spin-down, but slipped further down into the 1:1 resonance. Depending on its rheology, the innermost planet b may be captured in a stable pseudosynchronous rotation. Nonsynchronous rotation ensures higher levels of tidal dissipation and internal heating. The positive feedback between the viscosity and the dissipation rate—and the ensuing runaway heating—are terminated by a few self-regulation processes. When the temperature is high and the viscosity is low enough, the planet spontaneously leaves the 3:2 resonance. Further heating is stopped either by passing the peak dissipation or by the emergence of partial melt in the mantle. In the post-solidus state, the tidal dissipation is limited to the levels supported by the heat transfer efficiency. The tides on the host star are unlikely to have had a significant dynamical impact. The tides on the synchronized inner planets tend to reduce these planets’ orbital eccentricity, possibly contributing thereby to the system’s stability.

According to the concept of the seismic cycle, earthquakes result from the strain accumulation over a variable decade to millennial period, i.e., the interseismic stage, followed by a sudden stress release, i.e., the coseismic stage, eventually evolving in the postseismic stage. Common analytical and numerical approaches simulate interseismic, coseismic and postseismic stages independently. Often, coseismic models constrain the slip of single or multiple planar sources to fit the available geodetic and InSAR measurements to reproduce fault geometry, slip and regional deformation, regardless the origin of the interseismic forces. We developed a numerical model linking the ongoing interseismic viscous deformation at depth with the coseismic brittle episodic behavior of the upper crust. Our model assumes a brittle upper crust where the fault is locked, and a ductile lower crust, where the fault is steadily shearing. This approach is developed to model typical extensional and compressional earthquakes in Italy including the forces acting during the interseismic period, i.e., the lithostatic load and the horizontal stress field. We adjusted the setup of our model to simulate the interseismic, coseismic and postseismic phases of three seismic events in Italy, two extensional (2009 L’Aquila Mw 6.1 and 2016 Amatrice-Norcia Mw 6.5) and one contractional (2012 Emilia Mw 6). The results of our analysis, compared with the available geodetic and InSAR data, show that the proposed numerical model can reproduce the seismic cycle associated with the investigated events. The modeling provides evidence of interseismic dilatancy above the brittle-ductile transition at the bottom of the locked fault plane in the extensional tectonic setting; coseismic fault motion is triggered by the hangingwall gravitational collapse that recovers most of the interseismic dilatancy formed almost orthogonal to the fault. Vice versa, in contractional tectonic settings, the interseismic horizontal stress accumulates elastic energy in the crustal volume above the bottom of the locked fault; coseismic deformation recovers the elastic energy stored in the hangingwall. The two different settings generate a deformation in favor of gravity in extensional tectonic environments and against gravity in contractional tectonic environments.

Groundwater resources of the Southern High Plains/Ogallala Aquifer in Texas and New Mexico are being depleted due to groundwater mining for irrigation. Inevitably, resource depletion leads to calls for water conservation in agriculture. Conservation can take two forms: a reduction in irrigation depth, and a reduction in irrigated area, which in economics are termed the “intensive margin” and “extensive margin” of agricultural water use. In the Southern High Plains, we find different effects on water table elevation arising from these two approaches. This research presents a coupled model of landscape and groundwater hydrology. Model results indicate that a 50% reduction in irrigation water application would limit loss in irrigable area to about 1% of existing irrigable land per year. This is approximately half the rate of depletion from a ‘business as usual’ scenario. Relative benefits of each conservation approach varied: areas with a high density of irrigated land experienced greater benefits from a reduction in irrigation depth, whereas reducing irrigated acreage maintained water tables more in areas with a low density of irrigated land. This project demonstrates that strategies for irrigation water management can support conservation goals. However, model results also demonstrated that even a 50% reduction in irrigation water use –which would be politically and economically unfeasible in Texas and New Mexico – would still result in overall depletion of the regional aquifer.

On September 10, 2017, Hurricane Irma made landfall in the Florida Keys as a category 3 storm. Storm surge inundation heights in the lower Keys were in excess of 2m. In this study, we investigate the effect of the Hurricane Irma storm surge on the freshwater lens of Big Pine Key, FL using Electrical Resistivity Tomography (ERT) on three transect lines of 222 m, 250 m and 278 m length. Two transects, B1 and B3, were situated near the shoreline and crossed the lateral boundary of the previously mapped freshwater lens whereas, the third transect, B2, was inland in the interior of the lens. All transects experienced storm surge flooding from Irma. In this paper, we compare ERT imaging results of baseline data collected 6 years before Irma (November 2011) with data collected 3-4 months (November, 2017/January, 2018) and 8 months (May 2018) after the storm. The data were inverted using a difference inversion algorithm which uses the previous inversion results as a starting model. The resistivity models were then converted to salinity by applying an electrical formation factor. For the November 2017/January 2018 data, all profiles showed low resistivity/high salinity zones in the upper 2 m corresponding to saline water emplaced on top of the freshwater lens by the storm surge. The increase in salinity is most pronounced in the low elevation portions of the transects. On transects B1 and B2, the high salinity zones are mostly continuous. However, on the higher elevation sections of transect line B3, the high salinity zone is broken up and appears to be moving downward through the freshwater lens. The nearshore transects, B1 and B3 also show a greater amount of saltwater intrusion adjacent to the shoreline at depths below 5m. The May 2018 data were collected at the end of the climatological dry season but were collected immediately after 2 weeks of intense precipitation. These data show some limited recovery of the freshwater lens. This recovery is most pronounced in the lower elevation portions of the transects where standing water was observed during data collection. This suggests that both the impact of storm surge and the freshwater recovery due to precipitation are most pronounced in low elevation regions where both saline and fresh water can collect at the surface.