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Reoccupation of late Quaternary relative sea level indicators in a tectonically quasi-stable coastal area in Southern Italy (Cilento headland): Insights into the Last Interglacial stillstands
No full textA geomorphological-stratigraphical study, integrated with a modelling approach, has been employed to constrain the age of relative sea-level indicators (RSLi) along the quasi-stable Mt. Bulgheria coast in the southern Apennines, located on the eastern margin of the Tyrrhenian Sea. Focusing on the geological evidence of late Quaternary sea-level fluctuations within the 0 to 12 m above sea level (a.s.l.) elevation range, we describe RSLi along ca. 8 km of coastline and constrain their elevation, including those of previously undated RSLi in the same area. The reassessment of field data was needed to address the phenomenon of the reoccupation of older RSLi by younger ones. The approach employs the synchronous correlation method, integrating highstand peak elevations from global sea-level curves and a calibrated uplift rate value, derived from the correlation of RSLi-2 (currently at 8 ± 1 m a.s.l.) with Marine Isotope Stage (MIS) 9c, as suggested by recent findings. Overall, four RSLi are identified in the investigated coastal zone: RSLi-1 (11 ± 1 m a.s.l.), correlated with MIS 11; RSLi-2 (8 ± 1 m a.s.l.), correlated with MIS 9c and reoccupied during the first MIS 5e peak; RSLi-3 (4 ± 0.5 m a.s.l.) formed during an earlier, undefined stage and reoccupied during MIS 5e; RSLi-4 (2.5 ± 0.5 m a.s.l.) also assigned to MIS 5e. Notably, two cases of reoccupation of older RSLi by younger ones are here reported. By testing multiple global sea-level curves, we derived a range of possible uplift rates for the chronologically constrained RSLi-2. Consequently, assuming a constant uplift rate throughout the final part of the Middle Pleistocene, we sought the optimal match between all observed RSLi and predicted elevation of palaeo sea levels during past highstands. The preferred best fit was obtained using a composite eustatic curve from Waelbroeck et al. (2002) and Kopp et al. (2013, for within the MIS5e), and a constant uplift rate of 0.009 mm/yr. Our modelling of MIS 5e (Last Interglacial) identifies three sea-level stillstands and a rapid drop in sea level following the first and highest stillstand. Our results emphasize the importance of the reoccupation problem in sea-level reconstruction studies, especially for RSLi located in regions that are tectonically stable or with relatively low rates of crustal vertical movements. In such contexts, the sea level during younger interglacials may reach or exceed the elevations of older interglacials, reusing or modifying existing RSLi and complicating the identification of which sea-level stand created a specific shoreline feature. The calibrated model supports scenarios where MIS 5e, MIS 9c and MIS 11 had higher peaks than the Holocene (so far). Finally, this work challenges the assumption that RSL indicators ranging between 5 and 8 m a.s.l. in stable regions were exclusively formed during MIS 5e, emphasising the need for precise age constraints in these interpretations.PublishedJCR Journa
The unprecedented Md = 4.4, 2024, Campi Flegrei earthquake highlights the fluids contribution to the ongoing unrest
No full textThe Campi Flegrei caldera has been experiencing volcanic unrest since 2005, rising concern in the
population and in local and national authorities. On May 20, 2024, the largest local earthquake ever
instrumentally recorded up to that time produced substantial damage, forcing the evacuation of tens of
buildings west of the epicenter. At Campi Flegrei, M > 4 earthquakes are rare and their analysis is
crucial to understand the unrest dynamics and the relation between rupture and ground shaking
pattern, which is essential to mitigate the damage of future earthquakes. We analyse seismic
waveforms at local to regional distances to reconstruct the source geometry and kinematics. We
estimate millimetric to submillimetric coseismic surface subsidence– below the sensitivity of any
standard geodetic technique– which, compared to the general uplift, highlights the crucial role of deep
pressurized uids in earthquakes’ generation. Our results also indicate that rupture directivity and local
ampli cation determined the damage distribution.PublishedJCR Journa
Decoding Barva volcano: 26,700 years of eruptions and hazard implications
No full textBarva is an andesitic shield volcano located 23 km north of San Jos´ e (the capital of Costa Rica) and is the only
eruptive center near the capital that until now, has no record of historical eruptions. Recent mapping around the
summit indicates that at least eight explosive events (VEI 0–3) have occurred in the last 13 kyr. In the last 25 kyr,
eruption of several summit and flank lava flows, and cones with basaltic andesite to andesitic composition were
interspersed with prolonged dormancy periods. The most important and well-known lava field (12.8 km2)
erupted from the basaltic andesitic Monte de la Cruz cinder cone about 17 kyr on the South-southwest flank. The
explosive deposits confined to the summit area (within a radius of 10 km around the highest cones at 2906 m a.s.
l.) range from a lower tephra fall deposit layer dated at ~13,300 yr BP (from Guararí cone) to the most recent
strombolian event around ~250 yr BP (ca. 1700 CE) from Ur´ as cone. During the Holocene, the volcano has
experienced at least one subplinian (≥6 ×106 m3 DRE) and one strombolian eruption (~3 ×106 m3 DRE), with
frequent eruptions whose deposits are consistent with the vulcanian style (between ~2 ×106 and ~3.1 ×106 m3
DRE) originating from several small cones and craters at the summit. Periods of dormancy vary between ~750
and ~3820 yr, with approximately 325 yr of quiescence since the last small-volume eruption for which there are
no written records due the low population density during the middle of the seventeenth century and its normal
cloudy conditions. Results of our radiometric and field data analysis indicate that if explosions similar to those
that happened in the past 13 kyr occur in the coming centuries, there could be an impact on the towns near the
volcano (about 1200 people), mainly due to pyroclastic flows, ashfall and gas dispersion, while at the country
level, the main impact would be due to the dispersion and ashfall.PublishedOSV2: Complessità dei processi vulcanici: approcci multidisciplinari e multiparametriciJCR Journa
Scenario-based tsunami hazard assessment at Kolumbo submarine volcano
No full textPublishedJCR Journa
Forecasting the evolution of the 2021 Tajogaite eruption, La Palma, with TROPOMI/PlumeTraj-derived SO2 emission rates
No full textPublishedOSV2: Complessità dei processi vulcanici: approcci multidisciplinari e multiparametriciJCR Journa
Two phases of aseismic afterslip following the March 2021 Damasi, Greece, normal faulting earthquakes retrieved from InSAR measurements
No full textWe investigated the post-seismic period of the March 2021 Damasi-Tyrnavos (Thessaly, Greece) normal fault earthquakes by applying the multi-temporal interferometric Small Baseline Subset method. We processed 68 ascending Sentinel-1 acquisitions between 2020/03/15 and 2022/09/12. Our results identified three areas on the hanging wall of the ruptured faults showing non-linear deformation trends (systematic motion away from the satellite), and another area, on the footwall (systematic motion towards the satellite), interpreted as due to a post-seismic effect. Inversion of the InSAR data indicated the occurrence of afterslip co-planar to the sequence's two largest fault planes (M 6.3 and M 6.0, respectively). Most of the afterslip, with a peak of about 0.2 m, occurred on the fault corresponding to the 4 March 2021 event, at a depth of 7.5 km, while the fault corresponding to the M 6.3 event only showed very shallow adjustments and minor features at the border of the coseismic pattern. The transient uplift affected the footwall of the 3 March 2021 event and may indicate that the rupture nearly reached the surface towards the SW of the epicenter. The afterslip showed a fast phase lasting between March and August 2021 (5 months) and a second phase from March 2022 up to September 2022. A correlation between afterslip and relocated hypocenters indicates that most of the afterslip was aseismic. The moment release of the afterslip (fast phase) is about 7% that of the mainshocks.PublishedJCR Journa
Geodetic model of the 2024 January 22 Mw 7.0 Wushi (northwestern China) earthquake and Mw 5.7 aftershock from inversion of InSAR data
No full textOn 2024 January 22, an MW 7.0 earthquake struck the southern sector of the Tian Shan Mountains in Wushi County, northwestern China, causing damage and casualties. In this study, using Interferometric Synthetic Aperture Radar measurements (Sentinel-1 satellites), we constrained the geometry of the fault segment responsible for the seismic event, the coseismic slip distribution, and the source of the subsequent MW 5.7 aftershock deformation. Finally, we evaluated the potential state of stress of the unruptured portions of the causative fault as well as of adjacent fault segments, using the Coulomb stress failure function variations. Our findings indicate rupture along a transpressive left-lateral NNW dipping high-angle fault, associated with the Southern Tian Shan Fault alignment, likely the Maidan fault, with slip up to 3.5 m only occurring between 10 and 20 km depth. The position of the hypocentre with respect to our estimated slip distribution supports the evidence of a marked bilateral ENE–WSW rupture directivity during the mainshock. The modelling of the post-seismic deformation that includes the MW 5.7 aftershock occurred on 2024 January 29, and that is located about 15 km to the south of the mainshock, indicates a main patch with up to 90 cm of slip that may have occurred on a shallow back-thrust segment, in agreement with the observed surface breaks. We propose a potential structural and/or lithological influence on the coseismic rupture extent, consistent with observations from other intracontinental earthquakes. Finally, based on the Coulomb stress distribution computation, we find that the MW 5.7 aftershock was likely triggered by the preceding mainshock and that the Wushi earthquake also increased the stress level at both terminations of the modelled fault plane, particularly along the southwestwards continuation of the Maidan fault. In addition, we also find that a wide up-dip fault patch remained unruptured, and considering that these areas have been dynamically loaded it could represent potential further aseismic deformation and/or future significant ruptures, posing a continuing seismic hazard to Wushi County and surroundings areas.PublishedJCR Journa
Multi-Temporal Relative Sea Level Rise Scenarios up to 2150 for the Venice Lagoon (Italy)
No full textThis article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) licensePublishedJCR Journa
Radially Anisotropic 3D Velocity Model of the Central Apennines Lithosphere: The CI 23 Model
No full textWe present the first application of Full-Waveform Inversion (FWI) for a radially anisotropic 3D velocity model of the lithosphere beneath central Italy. The retrieved model CI 23 constrains P-wave (V PV , V PH) and S-wave velocities (V SV , V SH) in the period range 8-50 s. CI 23 model correlates well with regional lithological formations and highlights a negative radial anisotropy anomaly (V SH V SV) is observed in the area affected by the 2009 L'Aquila (AQ) seismic sequence. We interpret the velocity anomalies in terms of local tectonic structures, particularly the Olevano-Antrodoco-Sibillini (OAS) thrust-Gran Sasso Thrust (GST) systems, while also considering possible evidence of overpressured fluids and fluid migration. Additionally, the observed anomalies may reflect transient velocity variations induced by the ANV and AQ seismic sequences. Plain Language Summary Full-Waveform Inversion (FWI) retrieves accurate Earth models using complete waveform data. Here we implement this imaging technique to retrieve the first radially anisotropic 3D velocity model of the lithosphere beneath central Italy, one of the region with highest seismic hazard in Italy. The model highlights spatial variations of velocities that likely reflect local tectonics and fluid processes. Since the inverted data set mainly encompasses the two major sequences affecting the region (the 2016-2017 Amatrice-Visso-Norcia and the 2009 L'Aquila seismic sequences), we cannot exclude that the observed anomalies reflect transient variations of elastic properties induced by large seismic events along with their aftershocks.PublishedJCR Journa
Nuovi dati mineralogici e l'enigma della misenite
No full textLa Grotta dello zolfo è una zona di notevole interesse naturalistico e mineralogico situato nell'area dei Campi Flegrei, sul versante nord del cratere di Bacoli, in prossimità dei vulcani di Porto Miseno e di Miseno. E' una cavità naturale le cui pareti sono ricoperte da minerali di neoformazione, tra i quali soprattutto solfati idrati...PublishedN/A or not JC