ALBERT

Description: Author Posting. © American Geophysical Union, 2022. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Journal of Geophysical Research: Oceans 127(7), (2022): e2021JC018333, https://doi.org/10.1029/2021JC018333.

Description: As part of a project focused on the coastal fisheries of Isla Natividad, an island on the Pacific coast of Baja California, Mexico, we conducted a 2-1/2 year study of flows at two sites within the island's kelp forests. At one site (Punta Prieta), currents are tidal, whereas at the other site (Morro Prieto), currents are weaker and may be more strongly influenced by wind forcing. Satellite estimates of the biomass of the giant kelp (Macrocystis pyrifera) for this period varied between 0 (no kelp) and 3 kg/m2 (dense kelp forest), including a period in which kelp entirely was absent as a result of the 2014–2015 “Warm Blob” in the Eastern Pacific. During this natural “deforestation experiment”, alongshore velocities at both sites when kelp was present were substantially weaker than when kelp was absent, with low-frequency alongshore currents attenuated more than higher frequency ones, behavior that was the same at both sites despite differences in forcing. The attenuation of cross-shore flows by kelp was less than alongshore flows; thus, residence times for water inside the kelp forest, which are primarily determined by cross-shore velocities, were only weakly affected by the presence or absence of kelp. The flow changes we observed in response to changes in kelp density are important to the biogeochemical functioning of the kelp forest in that slower flows imply longer residence times, and, are also ecologically relevant in that reduced tidal excursions may lead to more localized recruitment of planktonic larvae.

Description: The work we describe here was supported by NSF grants DEB 1212124, OCE 1416934, OCE 1736830, and OCE 2022927, by an equipment grant from the Kuwait Foundation for the Advancement of Sciences, and through grants from the Marisla Foundation, Packard Foundation, and Walton Family Foundation.

Description: 2022-12-24

Description: Author Posting. © American Geophysical Union, 2022. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Geophysical Research Letters 49(12), (2022): e2021GL097598, https://doi.org/10.1029/2021GL097598.

Description: The ocean is inhomogeneous in hydrographic properties with diverse water masses. Yet, how this inhomogeneity has evolved in a rapidly changing climate has not been investigated. Using multiple observational and reanalysis datasets, we show that the spatial standard deviation (SSD) of the global ocean has increased by 1.4 ± 0.1% in temperature and 1.5 ± 0.1% in salinity since 1960. A newly defined thermohaline inhomogeneity index, a holistic measure of both temperature and salinity changes, has increased by 2.4 ± 0.1%. Climate model simulations suggest that the observed ocean inhomogeneity increase is dominated by anthropogenic forcing and projected to accelerate by 200%–300% during 2015–2100. Geographically, the rapid upper-ocean warming at mid-to-low latitudes dominates the temperature inhomogeneity increase, while the increasing salinity inhomogeneity is mainly due to the amplified salinity contrast between the subtropical and subpolar latitudes.

Description: This work is supported by the Strategic Priority Research Program of Chinese Academy of Sciences (grant XDB42000000 and XDB40000000), the National Key R&D Program of China (2017YFA0603200), and the Shandong Provincial Natural Science Foundation (ZR2020JQ17), and the U.S. National Science Foundation Physical Oceanography Program (OCE- 2048336).

Description: 2022-12-23

Description: We present here the results of a five-years-long earthquake educational project aiming to commemorate the hundredth anniversaries of five large Northern Apennines earthquakes occurred between 1916 and 1920 in the areas of: Rimini (1916, Mw 6.1), Valtiberina (1917, Mw 5.9), Romagna Apennines (1918, Mw 5.9), Mugello (1919, Mw 6.3) and Garfagnana (1920, Mw 6.5) earthquakes. We saw these anniversaries as the occasion for leading the Northern Apennines people to rediscover their past, in a positive way, and to improve their awareness of the earthquake as a natural feature of the regions in which they live. The activities that we planned for schools students encouraged them to go hunting for traces of the earthquakes of one hundred years ago in their home towns and to rediscover the memories and traditions of their communities. Together with their teachers, we also led the teenagers to find creative ways to involve the grownups in the process of discovery and knowledge. The Project had to cope with two emergencies: the great Central Italy earthquake of 2016-2017 and the Covid-19 epidemic. However, these stumbling blocks did not deter teachers and students from taking part in the process actively and even enthusiastically. Their families and communities were actively involved too. This experience taught us some valuable lessons. First of all, we learned to adapt the project, as we had conceived it at the start, to a wide gamma of social and cultural contexts. Not all the involved communities were equally aware of the level of seismic risk they are exposed to. On the affluent Adriatic coast, where tourism is the main source of income, past earthquakes are something best forgotten, by citizens and administrators alike. On the contrary, in the poorer inland mountain areas (Forlivese Apennines, Mugello, Garfagnana and Lunigiana) a more down-to-earth attitude prevails: earthquakes are looked upon as something that can and does happen and people are quick to grasp how important it is to contribute to initiatives whose aim is reducing seismic risk. Thus, we had to adapt our approach to the different contexts, modifying each time the activities we proposed to the schools with the aim of obtain the best possible results from each situation. Presentiamo i risultati di un progetto di educazione al rischio sismico attivato in occasione dei centenari di cinque terremoti storici che hanno colpito l’Appennino settentrionale tra gli anni 1916 e 1920 e precisamente i terremoti di Rimini 1916 (Mw 6.1), Valtiberina 1917 (Mw 5.9), Appennino romagnolo 1918 (Mw 5.9), Mugello 1919 (Mw 6.3) e Garfagnana 1920 (Mw 6.5). Abbiamo pensato di utilizzare questi anniversari come punto di partenza per accompagnare i cittadini a riappropriarsi del loro passato in modo positivo, facendo crescere la loro consapevolezza del terremoto come un carattere del loro ambiente naturale. A tal fine, nelle attività realizzate con le scuole, abbiamo incoraggiato gli studenti a cercare le tracce dei terremoti di un secolo fa nell’ambiente urbanizzato e a indagare le memorie e le tradizioni ancora presenti nelle comunità. Insieme ai loro insegnanti abbiamo spinto i ragazzi a trovare modi creativi per coinvolgere gli adulti in questo processo di scoperta e conoscenza. Il progetto è stato messo alla prova dal forte terremoto dell’Italia centrale (2016­2017) e dall’epidemia di Covid­19, ma nonostante queste difficoltà insegnanti e studenti hanno partecipato con grande interesse a questo percorso e hanno coinvolto nelle attività del progetto le famiglie e le comunità locali. Anche noi abbiamo imparato nuove lezioni. Un aspetto importante che abbiamo appreso è il bisogno di adattare il progetto a contesti sociali e culturali che si sono rivelati molto diversi. Le comunità coinvolte non condividono lo stesso livello di consapevolezza del rischio: sulla costa adriatica, a vocazione turistica, i terremoti sono qualcosa che è meglio dimenticare, sia da parte dei cittadini che dalle amministrazioni. Al contrario, nell’Appennino forlivese, nel Mugello, in Garfagnana e Lunigiana, i terremoti sono una presenza costante e le persone si sono sentite subito coinvolte in un processo attivo di riduzione del rischio e di attenzione quotidiana. Questo ci ha spinto ad adattare ogni volta l’approccio ai diversi contesti, modificando le proposte di attività che abbiamo realizzato nelle scuole.

Description: Lavoro realizzato nell’ambito della Convenzione fra INGV e Dipartimento della Protezione Civile, Allegato A, tematica “M”.

Description: Published

Description: 1-40

Description: 5SR TERREMOTI - Convenzioni derivanti dall'Accordo Quadro decennale INGV-DPC

Description: JCR Journal

Description: Author Posting. © American Geophysical Union, 2021. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Journal of Geophysical Research: Oceans 126(4), (2021): e2020JC016757, https://doi.org/10.1029/2020JC016757.

Description: The along-shelf circulation in the Northwest Atlantic (NWA) Ocean is characterized by an equatorward flow from Greenland's south coast to Cape Hatters. The mean flow is considered to be primarily forced by freshwater discharges from rivers and glaciers while its variability is driven by both freshwater fluxes and wind stress. In this study, we hypothesize and test that the wind stress is important for the mean along-shelf flow. A two-layer model with realistic topography when forced by wind stress alone simulates a circulation system on the NWA shelves that is broadly consistent with that derived from observations, including an equatorward flow from Greenland coast to the Mid-Atlantic Bight (MAB). The along-shelf sea-level gradient is close to a previous estimate based on observations. The along-shelf flows exhibit strong seasonal variations with along-shelf transports being strong in fall/winter and weak in spring/summer, consistent with available observations. It is found that the NWA shelf circulation is affected by both wind-driven gyres through their western boundary currents and wind-stress forcing on the shelf especially along the coasts of Newfoundland and Labrador. The local wind stress forcing has more direct impacts on flows in shallower waters along the coast while the open-ocean gyres tend to affect the circulations along the outer shelf. Our conclusion is that wind stress is an important forcing of the main along-shelf flows in the NWA. One objective of this study is to motivate further examination of whether wind stress is as important as freshwater forcing for the mean flow.

Description: Both Yang and Chen are also supported by NOAA Climate Program Office's Climate Variability and Prediction Program under grant NA20OAR4310398. JY is supported by Woods Hole Oceanographic Institution (WHOI) W. V. A. Clark Chair for Excellence in Oceanography and NSF Ocean Science Division under grant OCE1634886. Chen is supported by WHOI Independent Research and Development award.

Description: 2021-09-30

Description: Author Posting. © American Geophysical Union, 2022. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Geophysical Research Letters 49(12), (2022): e2022GL098087, https://doi.org/10.1029/2022GL098087.

Description: Radium isotopes are powerful proxies in oceanography and hydrology. Radium mass balance models, including assessments of submarine groundwater discharge (SGD), often overlook particle scavenging (PS) as a pathway for dissolved radium removal from the world ocean. Here, we build a global ocean 226Ra mass balance model and reevaluate the potential importance of PS. We find that PS is the major 226Ra sink for the upper ocean, removing about 96% of the total input from various sources. Aside from vertical exchange with the lower ocean, SGD is the largest 226Ra source into the upper ocean. The biological pump transfers particles to the deep ocean, resulting in a major but often overlooked impact on the global 226Ra marine budget. Our findings suggest that radium mass balance models should consider PS in systems with high siliceous algae production and export fluxes and long water residence times to prevent underestimation of large-scale SGD fluxes.

Description: The authors are grateful to the many researchers and funding agencies responsible for the collection of data and quality control. The authors are very grateful to Jesus Gomez-Velez of Vanderbilt University for suggesting the statistical approach for distribution expansion and helping with the coding. The authors from Ocean University of China were funded by the Natural Science Foundation of China 41876075, 42130410, and 91958214, and Fundamental Research Funds for the Central Universities China 201962003 and 202072001. Funding for M.A.C. was provided by U.S. National Science Foundation OCE-1736277 and a WHOI-OUC Cooperative Research Initiative award. Valentí Rodellas acknowledges financial support from the Beatriu de Pinós postdoctoral programme of the Catalan Government (2019-BP-00241).

Description: 2022-12-10

Description: Author Posting. © American Geophysical Union, 2022. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Geophysical Research Letters 49(12), (2022): e2022GL097779, https://doi.org/10.1029/2022GL097779.

Description: Outer-rise faults are predominantly concentrated near ocean trenches due to subducted plate bending. These faults play crucial roles in the hydration of subducted plates and the consequent subducting processes. However, it has not yet been possible to develop high-resolution structures of outer-rise faults due to the lack of near-field observations. In this study we deployed an ocean bottom seismometer (OBS) network near the Challenger Deep in the Southernmost Mariana Trench, between December 2016 and June 2017, covering both the overriding and subducting plates. We applied a machine-learning phase detector (EQTransformer) to the OBS data and found more than 1,975 earthquakes. An identified outer-rise event cluster revealed an outer-rise fault penetrating to depths of 50 km, which was inferred as a normal fault based on the extensional depth from tomographic images in the region, shedding new lights on water input at the southmost Mariana subduction zone.

Description: This study is supported by National Natural Science Foundation of China (Nos. 91858207, 92158205, 41890813), Hong Kong Research Grant Council Grants (No. 14304820), Award from CORE (a joint research center for ocean research between QNLM and HKUST), Chinese Academy of Sciences (Nos. Y4SL021001, QYZDY-SSW-DQC005), and Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou) (No. GML2019ZD0205), Faculty of Science at CUHK.

Description: 2022-12-06

Description: Author Posting. © American Geophysical Union, 2021. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Geophysical Research Letters 48(17), (2021): e2021GL094128, https://doi.org/10.1029/2021GL094128.

Description: Ocean warming is causing declines of coral reefs globally, raising critical questions about the potential for corals to adapt. In the central equatorial Pacific, reefs persisting through recurrent El Niño heatwaves hold important clues. Using an 18-year record of coral cover spanning three major bleaching events, we show that the impact of thermal stress on coral mortality within the Phoenix Islands Protected Area (PIPA) has lessened over time. Disproportionate survival of extreme thermal stress during the 2009–2010 and 2015–2016 heatwaves, relative to that in 2002–2003, suggests that selective mortality through successive heatwaves may help shape coral community responses to future warming. Identifying and facilitating the conditions under which coral survival and recovery can keep pace with rates of warming are essential first steps toward successful stewardship of coral reefs under 21st century climate change.

Description: Support was provided by the US National Science Foundation (NSF) 1737311 to A. L. Cohen; The Atlantic Donor Advised Fund to A. L. Cohen; a Woods Hole Oceanographic Institution post-doctoral scholarship to M. D. Fox; the Robertson Foundation, The Prince Albert Foundation, the New England Aquarium, and the Akiko Shiraki Dynner Fund.

Description: Author Posting. © American Geophysical Union, 2022. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Geophysical Research Letters 49(11), (2022): e2021GL097618, https://doi.org/10.1029/2021GL097618.

Description: Krypton-81 dating provides new insights into the timing, mechanisms, and extent of meteoric flushing versus retention of saline fluids in the subsurface in response to changes in geologic and/or climatic forcings over 50 ka to 1.2 Ma year timescales. Remnant Paleozoic seawater-derived brines associated with evaporites in the Paradox Basin, Colorado Plateau, are beyond the 81Kr dating range (〉1.2 Ma) and have likely been preserved due to negative fluid buoyancy and low permeability. 81Kr dating of formation waters above the evaporites indicates topographically-driven meteoric recharge and salt dissolution since the Late Pleistocene (0.03–0.8 Ma). Formation waters below the evaporites (up to 3 km depth), in basal aquifers, contain relatively young meteoric water components (0.4–1.1 Ma based on 81Kr) that partially flushed remnant brines and dissolved evaporites. We demonstrate that recent, rapid denudation of the Colorado Plateau (〈4–10 Ma) activated deep, basinal-scale flow systems as recorded in 81Kr groundwater age distributions.

Description: Funding for this research was provided by the W.M. Keck Foundation, CIFAR Earth 4D Subsurface Science and Exploration program, NSF EAR (#2120733), National Key Research and Development Program of China (Grant No. 2016YFA0302200), and National Natural Science Foundation of China (Grants No. 41727901). McIntosh and Ballentine are fellows of the CIFAR Earth4D Subsurface Science and Exploration program.

Description: The Global Navigation Satellite System (GNSS) represents a primary data source in Solid Earth Sciences. In order to investigate the Earth’s crustal deformation, time series of the estimated daily positions of the stations are routinely analyzed at the Istituto Nazionale di Geofisica e Vulcanologia (INGV) to investigate the deformation of the Earth’s surface caused by tectonic and non-tectonic processes. The GNSS observations of the stations are processed using the three main scientific software: GAMIT/GLOBK, BERNESE, and GIPSY OASIS II. The accuracy and the strength of geodetic solutions often depend on the geometry and spatial density of the network, and the availability and quality of GNSS data. In many circumstances, GNSS networks are deployed for topographic purposes by private or public institutions, and a significant number of GNSS stations in large regions acquire continuous observations. It may happen that such networks do not collect and distribute data according to IGS standards, so it could be difficult to analyze this data using automated data-processing tools. For that reason, this data is often ignored or partially used by the scientific community, despite their potential usefulness in geodynamic studies. We have attempted troubleshooting this problem by establishing a centralized storage facility in order to collect all available GNSS data and standardize both formats and metadata information. Here we describe the processes and functions that manage this unified repository, called MGA (Mediterranean GNSS Archive), which regularly collects GNSS RINEX files from alarge number of CORS (Continuously Operating Reference Station) located across a wide region of mainly the European and African plates. RINEX observation data and metadata information are provided to the analysts through an FTP server and dedicated web-services. The complete data set is stored in a PostgreSQL database in order to easily retrieve pieces of information and efficiently manage the archive content. The system implements many high-level services that include scripts to download files from remote archives and to detect new available data, web applications such as API (Application Program Interface) to interact with the system, and background services that interact with the database. During the development of this product, particular attention was paid to what has already been achieved by EPOS TCS WP10, whose objective was: "[...] to develop an open source platform with programmatic and web interfaces to store and disseminate raw data and metadata from GNSS stations operating in Europe''. Many ideas and tools presented here were inspired by that project.

Description: Published

Description: 1-18

Description: 2T. Deformazione crostale attiva

Description: 1IT. Reti di monitoraggio e sorveglianza

Description: 4IT. Banche dati

Description: N/A or not JCR

Description: SISMIKO è uno dei Gruppi Operativi di emergenza sismica dell’Istituto Nazionale di Geofisica e Vulcanologia (INGV) con la principale missione di installare, nel più breve tempo possibile, una rete sismica temporanea in tempo reale ad integrazione di quella permanente nell’area colpita da un forte terremoto e/o da una sequenza sismica [Moretti et al., 2012; 2016]. SISMIKO nasce formalmente nel 2015 ed è il frutto della convergenza di reti sismiche mobili gestite da diversi gruppi all’interno delle singole Sezioni e sedi dell’Ente. Ognuna di queste reti risente della propria storia, risponde ad esigenze territoriali diverse ed è caratterizzata da vari gradi di coinvolgimento nella gestione della Rete Sismica Nazionale (RSN) [Michelini et al., 2016; Margheriti et al., 2020]. Questa eterogeneità si riflette anche in differenze nel sistema di acquisizione dati delle stazioni gestite dal GO. Grazie ad una attenta predisposizione e configurazione della propria strumentazione, oggi SISMIKO ha la possibilità e le competenze per integrare in poche ore una rete temporanea trasmessa in tempo reale nel sistema di acquisizione dati sismologici attivo presso la sede INGV di Roma, contribuendo in maniera significativa al servizio di monitoraggio e sorveglianza sismica del territorio colpito dall’emergenza [Margheriti et al., 2020]. Nel corso del 2020, facendo seguito al piano di rinnovo e omogeneizzazione del parco strumentale dedicato GO avviato nel 2019 (co­finanziato nell’ambito della Convenzione tra INGV e il Dipartimento di Protezione Civile vigente), è stato deciso di sviluppare un sistema di acquisizione dati in tempo reale unificato per tutte le stazioni di SISMIKO, indipendente dalle singole sedi di appartenenza. Questa nuova logica ha diversi vantaggi, e in primis quello di rendere possibile il completo interscambio del personale presso le varie sedi INGV nella gestione dell’acquisizione dati, aspetto fondamentale durante una emergenza.

Description: Published

Description: 1-26

Description: 2SR TERREMOTI - Gestione delle emergenze sismiche e da maremoto

Description: N/A or not JCR