Browsing by Author "Esparza, Cesar"

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    Analysis of Climate-Related Risks for Chile's Coastal Settlements in the ARClim Web Platform
    (2022) Winckler, Patricio; Contreras-Lopez, Manuel; Garreaud, Rene; Meza, Francisco; Larraguibel, Cristian; Esparza, Cesar; Gelcich, Stefan; Falvey, Mark; Mora, Javiera
    The web-based tool ARClim provides an atlas of climate change-related risk assessments spanning over 50 environmental and productive sectors in Chile. This paper illustrates the implementation of ARClim on two coastal sectors, operational downtime in fishing coves and flooding in coastal settlements, aiming to provide a tool to visualize comparative estimates of risk, which may enable decision makers and stakeholders to prioritize adaptation measures. The risk is calculated as a function of the hazard, exposure, and sensitivity. Exposure and sensitivity are characterized using present day information. To assess the hazard, wave climate for a historical period (1985-2004) and a projection (2026-2045) were modeled with six general circulation models (GCMs) for an RCP8.5 scenario. Similarly, sea-level rise was computed from 21 GCMs. Results show that the flooding hazard is mostly dependent on sea-level rise, with waves playing a minor role. However, the flooding risk is highly variable along the coast, due to differences in the exposure, which strongly depends on the population of each settlement. The analysis of increased operational downtime in fishing coves also shows risk, which is dependent of the size of each site. Lastly, limitations of the analysis and opportunities for improvement are discussed.
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    Climate projections of oceanographic variables in the Exclusive Economic Zone of Ecuador: A 21st century perspective to inform impact and adaptation assessment
    (2024) Winckler, Patricio; Farias, Laura; Vicuna, Sebastian; Esparza, Cesar; Mora, Javiera; Chubretovic, Rosario; Cabrera, Francisco; Zambrano-Sanchez, Nicolas; Caza, Pablo; Gonzalez, Rosa Ana
    Climate projections of ocean variables are essential to inform adaptation strategies and plans involving open and coastal oceanic regions. Assessment of baseline and projections of sea surface temperature (SST), pH, dissolved oxygen (DO), mean sea level (MSL), waves coastal flooding within Ecuador's Exclusive Economic Zone, including Galapagos Islands are reported herein. With different magnitudes of change, both near-future (2021-2050) and far-future projections (2051-2080) show a statistically robust increase in SST, MSL rise and a reduction in pH, a proxy for acidification. In contrast, DO decrease is only observed in surface (0-100 m) but not in subsurface waters (100-400 m). The likelihood of extreme sea level events in the coastal cities of La Libertad, Manta and Esmeraldas would remain almost unchanged for near-future projections (2026-2045) whereas, for end-ofcentury projections (2081-2100), historical 1 in a 100-year extreme flooding events would become yearly occurrences. The generated data product offers a state-of-the-art research and management tool for the 21st century under the combined stressors of global climate change. Since the eastern Tropical Pacific Ocean is one of the most productive and biodiverse worldwide due to the equatorial upwelling system, possible impacts on marine biodiversity, social, and economic systems are discussed.
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    Decadal coastal evolution spanning the 2010 Maule earthquake at Isla Santa Maria, Chile: Framing Darwin's accounts of uplift over a seismic cycle
    (2023) Aedo, Diego; Cisternas, Marco; Melnick, Daniel; Esparza, Cesar; Winckler, Patricio; Saldana, Bladimir
    Charles Darwin and Robert FitzRoy documented coseismic coastal uplift associated with the great 1835 Chile earthquake (M > 8.5) at Isla Santa Maria. In 2010, another similar earthquake (Mw 8.8) uplifted the island, ending the seismic cycle. The 2-m uplift in 2010 caused major geomorphic and sedimentologic changes to the island's sandy beaches. Understanding the processes governing these changes requires pre- and post-earthquake measurements to differentiate the effects of abrupt coseismic uplift from seasonal, annual, and decadal-scale signals. Here, we combine spatial analysis of aerial imagery, field geophysics, wind and wave models to quantify geomorphic changes between 1941 and 2021 along the main beach. During the late interseismic phase (1941-2010), a ridge-runnel system was formed and then buried by a frontal dune. Because of uplift in 2010, the shoreline prograded similar to 20 m, the uplifted berm was abandoned, and a new seaward berm was built. In the following decade, the abandoned berm was eroded by widening of the backshore as the shoreline and dune advanced seaward. Over the surveyed eight decades, the shoreline prograded continuously, increasing from <1 m/year to up to 3-5 m/year after the earthquake. We infer that these changes were caused by a sedimentary disequilibrium driven by variations in relative sea level, moving formerly passive sands from eroding cliffs and marine depths into the coastal sedimentary system, thus promoting long and cross-shore sediment transport and, utterly, accretion. Our results have implications for studying beach evolution along tectonically-active coasts associated with drastic changes in relative sea level.