Water chemistry and trophic evaluation of Lake Albano (Central Italy): a four year water monitoring study

The crater lake Lake Albano is an increasingly diminishing water resource in terms of volume, the lake level has dropped more than four meters since the 1960s, and water quality resulting from elevated levels of nitrogen and phosphorus. The area of the lake, and the volcano as a whole, is also considered to be geologically hazardous due to continual shallow seismic activity, gaseous emissions and hydrothermal activity. Therefore, most research has been focussed on the geological aspects of the Albano lake system, whilst long-term limnological studies have been lacking. A meromictic classification was given to the lake, but this was based on one year studies of the surface water only. Presented and discussed are the results of a water chemistry and biological study of the full depth profile of Lake Albano from 2004 to 2008. During winter 2005-2006 the lake underwent a complete overturn, resulting in an influx of nutrient rich hypolimnetic water into the upper productive layers and oxygenated epilimnetic water into the deepest water layers. The effect of full overturn on the phytoplankton community is described and compared with those of meromictic years. The interplay between natural and anthropological processes on water quality and water usages is also discussed

Carta geologica del Comune di Roma alla scala 1:10.000, parte 1, 18 sezioni

Sezioni cartografiche del foglio Roma, completate nel corso dei rilevamenti previsti dal Progetto CARG. E' il primo rilievo geologico di un'area urbana italiana.Le carte sono state prodotte singolarmente a seguito di uno specifico accordo tra il Servizio Gelogico Nazionale (APAT), l'Ufficio Extradipartimentale per la Protezione Civile del Comune di Roma e il Dipartimento di Scienze Geologiche di Roma Tr

Modalities of flank collapse of volcanic edifices through analogue models.

Volcanic edifices are commonly subject to the collapse of their flanks. In order to better understand the modalities of flank collapse of volcanoes, as well as the possible triggering factors, we used analogue models. The length ratio between model and nature (˜10-4) requires, according to the scaling procedure, the combined use of dry quartz sand (87%) and flour (13%) to adequately simulate the behaviour of the volcanic edifice. Several modalities of sector collapses have been tested on circular and elongated cones: a) the basal failure of a cone, simulating the effect of an active extensional structure at the base of a volcano; b) the lateral removal of material from a cone, simulating the lack of lateral confinement of a volcano; c) the addition of material on the top of a cone, simulating the increase of mass on the summit of a volcano during repeated effusive eruptions; d) the injection of Newtonian silicone within the cone, simulating flank instabilities during the inflation of a volcano; e) the effect of a layer of silicone at the base of a cone, to simulate the effect of the basal spreading of a volcano over a weak substratum. The most important features controlling the modalities of flank collapse, as well as the similarities with the 2002 collapses at Stromboli and Etna, are highlighted

What controls soft and hard linkages within rift zones? Insights from analogue models.

Structures within rift zones exhibit two types of interaction: relay ramps or accommodation zones (soft linkages) and transfer faults (hard linkages). Analogue experiments have been performed to understand the conditions leading to these types of interaction. Sand (brittle crust analogue) overlies two adjacent silicone (ductile crust analogue) layers with different viscosity, in order to simulate crustal portions with differential percentage of extension De. The experiments show a distinct behaviour as a function of De. For De 21%, the interaction occurs by means of transfer faults subparallel to the extension direction, that is hard linkages. A comparison with rift zones shows a consistent behaviour. Soft linkages characterize narrow rifts and oceanic ridges, where the mean percentage of extension is low (e 39%), where the rift can locally achieve differential extension De > 21%

The seven hills of Rome - A geological tour of the Eternal City

A tourist's Introduction to the Geology of Rome. Center of the Western World - The Capitoline. Palaces and Gardens - The Palatine Hill. The Aventine Hill. The Tiber Floodplain, Commerce, and Tragedy. The Tiber's Tributarie in Rome - Clogged with Humankind's Debris. The Western Heights - Ianiculum, Vatican and Monte Mario. The Celian Hill. Largest of the Seven Hill - The Esquiline. Upper class - The Viminal and Quirinal Hill. Field Trips in and around Rom

Quaternary tectonic evolution of the central sector of Picentini Mountains (Southern Apennines) revealed by paleomagnetic and magnetic fabric analyses.

We present new paleomagnetic, Anisotropy of Magnetic Susceptibility (AMS), and structural data from the Acerno and Tizzano Quaternary intermontane basins, in the central sector of the Picentini Mts (Southern Apennines, Italy). The stratigraphic succession of these basins is related to fluvial-lacustrine depositional environments. The two basin outcrop at 750m and 900m a.s.l. respectively, and are well exposed because of the deep gorges excavated for hundred meters by the Tusciano river. The Acerno basin sedimentary sequence has been attributed to the Middle Pleistocene on the basis of radiometric ages obtained from volcanoclastic deposits. Conversely, the age of the Tizzano basin is essentially unknown, even if the basin has been considered older than the Acerno basin, on the basis of geomorphological evidences. We sampled 20 sites for paleomagnetic and AMS studies, in order to better constrain the age and the tectonic evolution of such basins. All the sites from the Acerno basin show a normal polarity, which confirm a Middle Pleistocene age for this sequence, according with radiometric age data. Conversely, paleomagnetic results from the Tizzano basin show an inverse polarity in the lower part of the stratigraphic section, and a normal polarity in the upper part. We interpret this reversal as the Brunhes-Matuyama boundary. AMS data show a well defined magnetic foliation parallel to the bedding planes, and a well defined magnetic lineation, with a shape of ellipsoids typically of weakly deformed sediments. The magnetic lineations obtained from the Tizzano basin cluster around a NNE-SSW trend, which is almost orthogonal to the NW-SE oriented normal faults which have been recognized in the field. The overall data set evidences that extensional tectonics in the Picentini Mts. was already active during the lower Pleistocene, along NW-SE normal faults

Processi di subsidenza nei depositi alluvionali olocenici nella Città di Roma. Caratteristiche stratigrafiche e geotecniche

The City of Rome is located in an area where long human activity and continuous transformation of the original terrain are tangible. The hydrographic networks of the Tiber's right and left banks have been modified more than once during historical times. Sometimes it has even been obliterated by urban growth (Capelli, G.,1999), so that today it is very hard, at least in the historical centre's area, to recognize the original terrain. Many of Rome’s streets run along the ancient courses of the Tiber's tributaries and many buildings lie upon alluvial deposits now buried by anthropogenic debris. Many structures overlying alluvium and debris have been damaged by subsidence and effects are visible in the buildings' uniform or differential settlement.In past, the alluvial deposits were considered as continuous bodies made of clayey-silty, sometimes sandy sediments. Instead, the formations are mainly heterogeneous and, as it will be made clear in this paper, consist of many facies (Kiersch, G.A,,1995). The geotechnical characterization of those units is mandatory for evaluating the geological environment's intrinsic hazard in urban areas, where the risk can reach very high values. This study has been carried out through the analysis of borehole and geotechnical data from three left-bank tributaries of the Tiber River the “Fosso del Velabro”, “Marrana della Caffarella”, “Fosso di Grotta Perfetta” and three right-bank tributaries (“Valle dell’Inferno”, a tributary stream of the “Fosso dei Tiradiavoli”, and the “Fosso della Maglianella”). Data about the Tiber’s alluvial deposit from various parts of the city were also included. Based on the geotechnical analysis, we created, for each deposit, a subdivision into lithotechnical units to make correlations and comparisons among the different deposits. The same level of detail has not been possible for all the stream valleys, since it is not always possible to obtain geotechnical data. Nonetheless, it is always been possible to define a stratigraphic series that would represent the examined deposit by subdividing it into units after stratigraphical and sedimentological observations