Papers by gabriella ruggieri
Uncertainty of GIA models across the Greenland
EGU General Assembly Conference Abstracts, Apr 1, 2013
Uncertainty of GIA models across the Greenland
Quaternary International, 2012
The main goals of this Ph.D. study are to investigate the regional and global geophysical compone... more The main goals of this Ph.D. study are to investigate the regional and global geophysical components related to present polar ice melting and to provide independent cross validation checks of GIA models using both geophysical data detected by satellite mission, and geological observations from far field sites, in order to determine a lower and upper bound of uncertainty of GIA effect. The subject of this Thesis is the sea level change from decades to millennia scale. Within ice2sea collaboration, we developed a Fortran numerical code to analyze the local short-term sea level change and vertical deformation resulting from the loss of ice mass. This method is used to investigate polar regions: Greenland and Antarctica. We have used mass balance based on ICESat data for Greenland ice sheet and a plausible mass balance for Antarctic ice sheet. We have determined the regional and global fingerprint of sea level variations, vertical deformations of the solid surface of the Earth and varia...
Bulletin of Earthquake Engineering, Dec 6, 2019
The 2012 Emilia-Romagna earthquake, that mainly struck the homonymous Italian region provoking 28... more The 2012 Emilia-Romagna earthquake, that mainly struck the homonymous Italian region provoking 28 casualties and damage to thousands of structures and infrastructures, is an exceptional source of information to question, investigate, and challenge the validity of seismic fragility functions and loss curves from an empirical standpoint. Among the most recent seismic events taking place in Europe, that of Emilia-Romagna is quite likely one of the best documented, not only in terms of experienced damages, but also for what concerns occurred losses and necessary reconstruction costs. In fact, in order to manage the compensations in a fair way both to citizens and business owners, soon after the seismic sequence, the regional administrative authority started (1) collecting damage and consequence-related data, (2) evaluating information sources and (3) taking care of the crosschecking of various reports. A specific database-so-called Sistema Informativo Gestione Europa (SFINGE)-was devoted to damaged business activities. As a result, 7 years after the seismic events, scientists can rely on a one-of-a-kind, vast and consistent database, containing information about (among other things): (1) buildings' location and dimensions, (2) occurred structural damages, (3) experienced direct economic losses and (4) related reconstruction costs. The present work is focused on a specific data subset of SFINGE, whose elements are Long-Span-Beam buildings (mostly precast) deployed for business activities in industry, trade or agriculture. With the available set of data, empirical fragility functions, cost and loss ratio curves are elaborated, that may be included within existing Performance Based Earthquake Engineering assessment toolkits.
Earthquake Spectra, Nov 1, 2019
This preprint is a PDF of a manuscript that has been accepted for publication in Earthquake Spect... more This preprint is a PDF of a manuscript that has been accepted for publication in Earthquake Spectra. It is the final version that was uploaded and approved by the author(s). While the paper has been through the usual rigorous peer review process for the Journal, it has not been copyedited, nor have the figures and tables been modified for final publication. Please also note that the paper may refer to online Appendices that are not yet available. We have posted this preliminary version of the manuscript online in the interest of making the scientific findings available for distribution and citation as quickly as possible following acceptance. However, readers should be aware that the final, published version will look different from this version and may also have some differences in content.
Bulletin of Earthquake Engineering, 2019
The 2012 Emilia-Romagna earthquake, that mainly struck the homonymous Italian region provoking 28... more The 2012 Emilia-Romagna earthquake, that mainly struck the homonymous Italian region provoking 28 casualties and damage to thousands of structures and infrastructures, is an exceptional source of information to question, investigate, and challenge the validity of seismic fragility functions and loss curves from an empirical standpoint. Among the most recent seismic events taking place in Europe, that of Emilia-Romagna is quite likely one of the best documented, not only in terms of experienced damages, but also for what concerns occurred losses and necessary reconstruction costs. In fact, in order to manage the compensations in a fair way both to citizens and business owners, soon after the seismic sequence, the regional administrative authority started (1) collecting damage and consequence-related data, (2) evaluating information sources and (3) taking care of the cross-checking of various reports. A specific database—so-calledSistema Informativo Gestione Europa(SFINGE)—was devoted...
Earthquake Spectra, 2019
The seismic events that struck the Italian region Emilia-Romagna in 2012 provoked not only numero... more The seismic events that struck the Italian region Emilia-Romagna in 2012 provoked not only numerous injuries and casualties but also vast damage to thousands of buildings, infrastructures, and production sites. In particular, unlike other Italian sequences, that of 2012 was notable for the high value of losses in the industrial sector. Soon after the earthquakes, plans were set up in order to provide financial help to both citizens and enterprises, and to this aim the regional authority gathered and classified damage and loss reports. Information was collected in a database called SFINGE. This study is an empirical data analysis of a consistent subset of SFINGE, whose elements are long-span-beam buildings used as production sites. Results are in terms of direct economic losses and cost of reconstruction. This work is a precious source of seismic economic consequence assessment tools for the considered building typology, within the framework of Performance-Based Earthquake Engineering.
Schema idrogeologico della Piana di Sulmona (AQ)
Constraining Quaternary sea level using U-Th ages of Phreatic Overgrowths on Speleothems from coastal caves. A critical review
Geophysical Journal International, Apr 5, 2012
We study the implications of a recently published mass balance of the Greenland ice sheet (GrIS),... more We study the implications of a recently published mass balance of the Greenland ice sheet (GrIS), derived from repeated surface elevation measurements from NASA's ice cloud and land elevation satellite (ICESat) for the time period between 2003 and 2008. To characterize the effects of this new, high-resolution GrIS mass balance, we study the time-variations of various geophysical quantities in response to the current mass loss. They include vertical uplift and subsidence, geoid height variations, global patterns of sea level change (or fingerprints), and regional sea level variations along the coasts of Greenland. Long-wavelength uplifts and gravity variations in response to current or past ice thickness variations are obtained solving the sea level equation, which accounts for both the elastic and the viscoelastic components of deformation. To capture the short-wavelength components of vertical uplift in response to current ice mass loss, which is not resolved by satellite gravity observations, we have specifically developed a high-resolution regional elastic rebound (ER) model. The elastic component of vertical uplift is combined with estimates of the viscoelastic displacement fields associated with the process of glacial-isostatic adjustment (GIA), according to a set of published ice chronologies and associated mantle rheological profiles. We compare the sensitivity of global positioning system (GPS) observations along the coasts of Greenland to the ongoing ER and GIA. In notable contrast with past reports, we show that vertical velocities obtained by GPS data from five stations with sufficiently long records and from one tide gauge at the GrIS margins can be reconciled with model predictions based on the ICE-5G deglaciation model and the ER associated with the new ICESat-derived mass balance.
Quaternary Science Reviews, May 1, 2015
The contribution of the Antarctic ice sheet (AIS) to deglacial sea-level rise is poorly constrain... more The contribution of the Antarctic ice sheet (AIS) to deglacial sea-level rise is poorly constrained. This shortfall gives rise to concerns because incorrect AIS estimates impact significantly on our ability to predict sea-level change in the course of global warming. Given the scarcity of geological data and the complexity of the Antarctic response to glacio-isostatic adjustment processes, there is a need for accurate data to constrain the timing of the ice-sheet retreat. Here, we provide such data on the Holocene Antarctic melting through an isolated geographic site on the northern hemisphere, which we show is sensitive to the Antarctic signal. Using both our site, and other mid-latitudinal relative sea-level sites, our model provides a consensus estimate that the AIS released water corresponding to 5 m equivalent sea level at 8 ka and ceased melting at 6 ka. This is different to most AIS models, which release an equal amount of water at 11 ka or after 6 ka. Our findings change model assumptions about the terminal AIS melting and show that future Holocene sea-level research should focus on broad shelves and large coast embayments in the mid latitudes.
Constraining Quaternary sea level using U-Th ages of Phreatic Overgrowths on Speleothems from coastal caves. A critical review
Geophysical implications of presen-day and late Pleistocene ice melting across New Zealand
According to the estimation given by Chinn (2001) in total a 53 km3 of ice volume was accumulated... more According to the estimation given by Chinn (2001) in total a 53 km3 of ice volume was accumulated over New Zealand during the Pleistocene covering an area of about 1160 km2 concentrated mainly along the South Island between 42 and 46 arc-deg of southern latitudes. Most recently a new mass balance monitoring program has been established with on-site support by the World Glaciers Monitoring Service (WGMS). Chinn (1996) suggests an increase retreating of glaciers with a net ice volume loss between 1977 and 2005 of about 11% (Unep, 2008). In this study we investigate the sensitivity of New Zealand's coastal regions to decadal glaciers melting (estimated by Chinn 1996) by means of sea level change and bedrock deformations. A regional present-day ice melting model, composed by disc loads with fixed positions spaced in order to minimize the overlaps, is developed and applied. We provide an estimate of the global patterns of sea level (fingerprints) associated with the melting of New Ze...
Quaternary Science Reviews, 2015
The contribution of the Antarctic ice sheet (AIS) to deglacial sea-level rise is poorly constrain... more The contribution of the Antarctic ice sheet (AIS) to deglacial sea-level rise is poorly constrained. This shortfall gives rise to concerns because incorrect AIS estimates impact significantly on our ability to predict sea-level change in the course of global warming. Given the scarcity of geological data and the complexity of the Antarctic response to glacio-isostatic adjustment processes, there is a need for accurate data to constrain the timing of the ice-sheet retreat. Here, we provide such data on the Holocene Antarctic melting through an isolated geographic site on the northern hemisphere, which we show is sensitive to the Antarctic signal. Using both our site, and other mid-latitudinal relative sea-level sites, our model provides a consensus estimate that the AIS released water corresponding to 5 m equivalent sea level at 8 ka and ceased melting at 6 ka. This is different to most AIS models, which release an equal amount of water at 11 ka or after 6 ka. Our findings change model assumptions about the terminal AIS melting and show that future Holocene sea-level research should focus on broad shelves and large coast embayments in the mid latitudes.
Tectonophysics, 2011
On time scales from decades to centuries, continental cryospheric forcing in response to climate ... more On time scales from decades to centuries, continental cryospheric forcing in response to climate change constitutes a major source of isostatic disequilibrium that may influence future regional sea level variations. Current vertical displacements and gravity field variations are often estimated neglecting rheological effects and thus assuming a fully elastic response of the Earth. In this study, we adopt a more general point of view, aiming at describing ongoing surface movements resulting from recent glacial instabilities, also taking into account the effects associated with shallow upper mantle and crustal rheologies. Our computations are based on the Post-Widder Laplace inversion formula, which permits the straightforward computation of loaddeformation coefficients for steady state and transient rheologies up to very high harmonic degrees. Using a surface load with a simple geometry and time history, we compare the classical elastic solutions to those obtained considering the rheological response of the shallow upper mantle. While at the center of the ice sheet rheology only magnifies the elastic response, the pattern and time history of vertical displacement at the ice sheet margins show a greater complexity, mainly due to the development of lateral forebulges whose shape and amplitude are particularly sensitive to the rheology of the shallow upper mantle. In this region, assuming an elastic rheology is generally appropriate on a century time scale, but significant deviations from a purely elastic response (both sign and amplitude) are observed at longer time scales or when a low viscosity zone with Maxwell rheology is taken into account.
Middle-Holocene highstand in southeast Tunisia
Geophysical Journal International, 2012
We study the implications of a recently published mass balance of the Greenland ice sheet (GrIS),... more We study the implications of a recently published mass balance of the Greenland ice sheet (GrIS), derived from repeated surface elevation measurements from NASA's ice cloud and land elevation satellite (ICESat) for the time period between 2003 and 2008. To characterize the effects of this new, high-resolution GrIS mass balance, we study the time-variations of various geophysical quantities in response to the current mass loss. They include vertical uplift and subsidence, geoid height variations, global patterns of sea level change (or fingerprints), and regional sea level variations along the coasts of Greenland. Long-wavelength uplifts and gravity variations in response to current or past ice thickness variations are obtained solving the sea level equation, which accounts for both the elastic and the viscoelastic components of deformation. To capture the short-wavelength components of vertical uplift in response to current ice mass loss, which is not resolved by satellite gravity observations, we have specifically developed a high-resolution regional elastic rebound (ER) model. The elastic component of vertical uplift is combined with estimates of the viscoelastic displacement fields associated with the process of glacial-isostatic adjustment (GIA), according to a set of published ice chronologies and associated mantle rheological profiles. We compare the sensitivity of global positioning system (GPS) observations along the coasts of Greenland to the ongoing ER and GIA. In notable contrast with past reports, we show that vertical velocities obtained by GPS data from five stations with sufficiently long records and from one tide gauge at the GrIS margins can be reconciled with model predictions based on the ICE-5G deglaciation model and the ER associated with the new ICESat-derived mass balance.
Late Holocene Sea Level Reconstructions Based on Observations of Roman Fish Tanks, Tyrrhenian Coast of Italy
Geoarchaeology, 2012
We present estimates for late Holocene relative sea level change along the Tyrrhenian coast of It... more We present estimates for late Holocene relative sea level change along the Tyrrhenian coast of Italy based on morphological characteristics of eight submerged Roman fish tanks (piscinae) constructed between the 1st century B.C. and the 2nd century A.D. Underwater geomorphological features and archaeological remains related to past sea level have been measured and corrected using recorded tidal values. We conclude that local sea level during the Roman period did not exceed 58 ± 5 cm below the present sea level. These results broadly agree with previous observations in the region but contrast with recent analysis that suggests a significantly larger sea level rise during the last 2000 years. Using a glacial isostatic adjustment model, we explain how regional sea level change departs from the eustatic component. Our calculation of relative sea level during the Roman period provides a reference for isolating the long‐wavelength contribution to sea level change from secular sea level ris...
Uploads
Papers by gabriella ruggieri