Flow dynamics at the continental scale: Streamflow correlation and hydrological similarity     

Andrea Betterle  Mario Schirmer  Gianluca Botter 《水文研究》2019,33(4):627-646

Streamflow variability in space and time critically affects anthropic water uses and ecosystem services. Unfortunately, spatiotemporal patterns of flow regimes are often unknown, as discharge measurements are usually recorded at a limited number of hydrometric stations unevenly distributed along river networks. Advances in understanding the physical processes that control the spatial patterns of river flows are therefore necessary to predict water availability at ungauged locations or to extrapolate pointwise streamflow observations. This work explores the use of the spatial correlation of river flows as a metric to quantify the similarity between hydrological responses of two catchments. Following a stochastic framework, 340,000 cross‐correlations between pairs of daily streamflows time series are predicted at a seasonal timescale across the contiguous United States using 413 catchments of the MOPEX dataset. Model predictions of streamflow correlation obtained in absence of run‐off information are successfully used to identify catchment outlets sharing similar discharge dynamics and flow regimes across a broad range of geomorphoclimatic conditions, without relying on calibration. The selection of reference streamgauges based on predicted streamflow correlation generally outperforms the selection based on spatial proximity, especially as the density of available gauged sections decreases. Interestingly, correlated outlets share a broad spectrum of hydrological signatures (mean discharge, flow variability, and recession properties), suggesting that catchments forced by analogous frequency and intensity of effective rainfall events might exhibit common geomorphoecological traits leading to similar hydrological responses. The proposed framework provides a physical basis to assist the regionalization of flow dynamics and to interpret the spatial variability of flow regimes along stream networks.  相似文献   

Earth's spin and volcanic eruptions: evidence for mutual cause‐and‐effect interactions?     

Danilo M. Palladino  Gianluca Sottili 《地学学报》2014,26(1):78-84

The angular velocity of Earth's rotation shows decadal oscillations due to the lunisolar gravitational torque, as well as inter‐ or intra‐annual changes arising from the angular momentum exchange between the atmosphere and the solid Earth. The energies involved in the Length of Day (LOD) variations may affect the crustal deformation rate and seismic energy release on a global scale. We found significant correlation between the occurrences of major volcanic eruptions and the LOD pattern since AD 1750. On a multiyear scale, eruption frequency worldwide increases with LOD changes. Moreover, the injection of sulphur gases into the atmosphere during major eruptions is accompanied by significant inter‐annual LOD variations. This provides evidence of complex mutual cause‐and‐effect interactions: stress changes induced by multiyear variations in Earth's spin may affect climactic volcanic activity; also, the atmosphere's dynamic response to volcanic plumes may result in global changes of wind circulation and climate, with consequent LOD variations.  相似文献   

Central Mediterranean tephrochronology between 313 and 366 ka: New insights from the Fucino palaeolake sediment succession     

Niklas Leicher  Biagio Giaccio  Alison Pereira  Sebastien Nomade  Lorenzo Monaco  Giorgio Mannella  Paolo Galli  Edoardo Peronance  Danilo Mauro Palladino  Gianluca Sottili  Giovanni Zanchetta  Bernd Wagner 《Boreas: An International Journal of Quaternary Research》2023,52(2):240-271

Thirty-two tephra layers were identified in the time-interval 313–366 ka (Marine Isotope Stages 9–10) of the Quaternary lacustrine succession of the Fucino Basin, central Italy. Twenty-seven of these tephra layers yielded suitable geochemical material to explore their volcanic origins. Investigations also included the acquisition of geochemical data of some relevant, chronologically compatible proximal units from Italian volcanoes. The record contains tephra from some well-known eruptions and eruptive sequences of Roman and Roccamonfina volcanoes, such as the Magliano Romano Plinian Fall, the Orvieto–Bagnoregio Ignimbrite, the Lower White Trachytic Tuff and the Brown Leucitic Tuff. In addition, the record documents eruptions currently undescribed in proximal (i.e. near-vent) sections, suggesting a more complex history of the major eruptions of the Colli Albani, Sabatini, Vulsini and Roccamonfina volcanoes between 313 and 366 ka. Six of the investigated tephra layers were directly dated by single-crystal-fusion ⁴⁰Ar/³⁹Ar dating, providing the basis for a Bayesian age–depth model and a reassessment of the chronologies for both already known and dated eruptive units and for so far undated eruptions. The results provide a significant contribution for improving knowledge on the peri-Tyrrhenian explosive activity as well as for extending the Mediterranean tephrostratigraphical framework, which was previously based on limited proximal and distal archives for that time interval.  相似文献   

Improving the Monitoring of the Status of the Environment Through Web Geo‐services: The Example of Large Structures Supervision     

Maria A. Brovelli  Gianluca Giori  Mauro Mussin  Marco Negretti 《Transactions in GIS》2011,15(2):173-188

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Reconstruction of the eruptive activity on the NE sector of Stromboli volcano: timing of flank eruptions since 15 ka   总被引：1，自引：0，他引：1  

Sonia Calvari  Stefano Branca  Rosa Anna Corsaro  Emanuela De Beni  Lucia Miraglia  Gianluca Norini  Jan Wijbrans  Enzo Boschi 《Bulletin of Volcanology》2011,73(1):101-112

A multidisciplinary geological and compositional investigation allowed us to reconstruct the occurrence of flank eruptions on the lower NE flank of Stromboli volcano since 15 ka. The oldest flank eruption recognised is Roisa, which occurred at ~15 ka during the Vancori period, and has transitional compositional characteristics between the Vancori and Neostromboli phases. Roisa was followed by the San Vincenzo eruption that took place at ~12 ka during the early stage of Neostromboli period. The eruptive fissure of San Vincenzo gave rise to a large scoria cone located below the village of Stromboli, and generated a lava flow, most of which lies below sea level. Most of the flank eruptions outside the barren Sciara del Fuoco occurred in a short time, between ~9 and 7 ka during the Neostromboli period, when six eruptive events produced scoria cones, spatter ramparts and lava flows. The Neostromboli products belong to a potassic series (KS), and cluster in two differently evolved groups. After an eruptive pause of ~5,000 years, the most recent flank eruption involving the NE sector of the island occurred during the Recent Stromboli period with the formation of the large, highly K calc-alkaline lava flow field, named San Bartolo. The trend of eruptive fissures since 15 ka ranges from N30°E to N55°E, and corresponds to the magma intrusions radiating from the main feeding system of the volcano.  相似文献   

New results of ⁴⁰Ar/³⁹Ar dating constrain the timing of transition from fissure-type to central volcanism at Mount Etna (Italy)     

Emanuela De Beni  Jan R. Wijbrans  Stefano Branca  Mauro Coltelli  Gianluca Groppelli 《地学学报》2005,17(3):292-298

Recent geological studies performed at Etna allow reassessing the stratigraphic frame of the volcano where distinct evolutionary phases are defined. This stratigraphic reconstruction was chronologically constrained on the basis of a limited number of U–Th and K–Ar age determinations whose uncertainty margins are sometimes too wide. For this reason, we successfully adopted at Etna the ⁴⁰Ar/³⁹Ar technique that allowed obtaining more precise age determinations. The incremental heating technique also gives information on sample homogeneity, and potential problems of trapped argon. Five samples were collected from stratigraphically well-controlled volcanic units in order to chronologically define the transition between the fissure-type volcanism of the Timpe phase to the central volcanism of the Valle del Bove Centers. Isotopic ages with an uncertainty margin of 2–4% have been obtained emphasizing that this transition occurred (130–126 ka) without significant temporal hiatus.  相似文献   

Middle Pleistocene to Holocene activity of the Gondola Fault Zone (Southern Adriatic Foreland): Deformation of a regional shear zone and seismotectonic implications     

Domenico Ridente  Umberto Fracassi  Daniela Di Bucci  Fabio Trincardi  Gianluca Valensise 《Tectonophysics》2008,453(1-4):110

Recent seismicity in and around the Gargano Promontory, an uplifted portion of the Southern Adriatic Foreland domain, indicates active E–W strike-slip faulting in a region that has also been struck by large historical earthquakes, particularly along the Mattinata Fault. Seismic profiles published in the past two decades show that the pattern of tectonic deformation along the E–W-trending segment of the Gondola Fault Zone, the offshore counterpart of the Mattinata Fault, is strikingly similar to that observed onshore during the Eocene–Pliocene interval. Based on the lack of instrumental seismicity in the south Adriatic offshore, however, and on standard seismic reflection data showing an undisturbed Quaternary succession above the Gondola Fault Zone, this fault zone has been interpreted as essentially inactive since the Pliocene. Nevertheless, many investigators emphasised the genetic relationships and physical continuity between the Mattinata Fault, a positively active tectonic feature, and the Gondola Fault Zone. The seismotectonic potential of the system formed by these two faults has never been investigated in detail. Recent investigations of Quaternary sedimentary successions on the Adriatic shelf, by means of very high-resolution seismic–stratigraphic data, have led to the identification of fold growth and fault propagation in Middle–Upper Pleistocene and Holocene units. The inferred pattern of gentle folding and shallow faulting indicates that sediments deposited during the past ca. 450 ka were recurrently deformed along the E–W branch of the Gondola Fault Zone.We performed a detailed reconstruction and kinematic interpretation of the most recent deformation observed along the Gondola Fault Zone and interpret it in the broader context of the seismotectonic setting of the Southern Apennines-foreland region. We hypothesise that the entire 180 km-long Molise–Gondola Shear Zone is presently active and speculate that also its offshore portion, the Gondola Fault Zone, has a seismogenic behaviour.  相似文献   

A mechanistic approach reveals non linear effects of climate warming on mussels throughout the Mediterranean sea     

Valeria Montalto  Brian Helmuth  Paolo M Ruti  Alessandro Dell’Aquila  Alessandro Rinaldi  Gianluca Sarà 《Climatic change》2016,139(2):293-306

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Towards a better understanding of the evolution of the flood risk in Mediterranean urban areas: the case of Barcelona     

Maria Cortès  Maria Carmen Llasat  Joan Gilabert  Montserrat Llasat-Botija  Marco Turco  Raül Marcos  Juan Pedro Martín Vide  Lluís Falcón 《Natural Hazards》2018,93(1):39-60

This contribution explores the evolution of the flood risk in the Metropolitan Area of Barcelona (MAB; Northeast Spain) from 1981 to 2015, and how it has been affected by changes in land use, population and precipitation. To complete this study, we analysed PRESSGAMA and INUNGAMA databases to look for all the information related to the floods and flash floods that have affected the chosen region. The “Consorcio de Compensación de Seguros”, a state insurance company for extraordinary risks, provided data on economic damage. The extreme precipitation trend was analysed by the Fabra Observatory and El Prat-Airport Observatory, and daily precipitation data were provided by the State Meteorological Agency of Spain (AEMET) and the Meteorological Service of Catalonia (SMC). Population data were obtained from the Statistical Institute of Catalonia (IDESCAT). Changes in land use were estimated from the land use maps for Catalonia corresponding to 1956, 1993, 2000, 2005 and 2009. Prevention measures like rainwater tanks and improvements to the drainage system were also been considered. The specific case of Barcelona is presented, a city recognised by United Nations International Strategy for Disaster Reduction as a model city for urban resilience to floods. The evolution of flood events in the MAB does not show any significant trend for this period. We argue that the evolution in floods can be explained, at least in part, by the lack of trend in extreme precipitation indices, and also by the improvements in flood prevention measures.  相似文献   

Early and middle Holocene in the Aegean Sea: interplay between high and low latitude climate variability     

Gianluca Marino  Eelco J. Rohling  Francesca Sangiorgi  Angela Hayes  James L. Casford  André F. Lotter  Michal Kucera  Henk Brinkhuis 《Quaternary Science Reviews》2009,28(27-28):3246-3262

Changes in the orbital parameters, solar output, and ocean circulation are widely considered as main drivers of the Holocene climate. Yet, the interaction between these forcings and the role that they play to produce the pattern of changes observed in different domains of the climate system remain debated. Here, we present new early to middle Holocene season-specific sea surface temperature (SST) and δ¹⁸O_seawater results, based on organic-walled dinoflagellate cyst and planktonic foraminiferal data from two sediment cores located in the central (SL21) and south-eastern (LC21) Aegean Sea (eastern Mediterranean). Today, this region is affected by high to mid latitude climate in winter and tropical/subtropical climate in summer. The reconstructed δ¹⁸O_seawater from LC21 displays a marked (～1.3%) negative shift between 10.7 and 9.7 ka BP, which represents the regional expression of the orbitally driven African monsoon intensification and attendant freshwater flooding into the eastern Mediterranean. A virtually contemporaneous shift, of the same sign and magnitude, is apparent in the δ¹⁸O_speleothem record from Soreq Cave (Northern Israel), an important part of which may therefore reflect a change in the isotopic composition of the moisture source region (Aegean and Levantine Seas). Our SST reconstructions show that Aegean winter SSTs decreased in concert with intensifications of the Siberian High, as reflected in the GISP2 nss [K⁺] record. Specifically, three distinct sea surface cooling events at 10.5, 9.5–9.03 and 8.8–7.8 ka BP in the central Aegean Sea match increases in GISP2 nss [K⁺]. These events also coincide with dry interludes in Indian monsoon, hinting at large (hemispheric) scale teleconnections during the early Holocene on centennial timescales. A prominent short-lived (～150 years) cooling event in core SL21 – centred on 8.2 ka BP – is coeval to the ‘8.2 ka BP event’ in the Greenland δ¹⁸O_ice, which is commonly linked to a melt-water related perturbation of the Atlantic Meridional Overturning Circulation and associated ocean heat transport. By deciphering the phasing between a recently published record of reduced overflow from the Nordic Seas into the northern North Atlantic, the Greenland δ¹⁸O_ice ‘8.2 ka BP event’ anomaly, and the short-lived cooling in SL21, we demonstrate severe far-field impacts of this North Atlantic event in the Aegean Sea. The Aegean is isolated from the North Atlantic oceanic circulation, so that signal transmission must have been of an atmospheric nature.  相似文献