ALBERT

Description: To date, the origin of the Campi Flegrei caldera is still under debate and may be related to (1) a single caldera collapse associated with the Neapolitan Yellow Tuff (NYT) eruption, (2) two subsequent caldera collapses associated with the NYT and the preceding Campanian Ignimbrite (CI) eruptions forming a nested-caldera complex, or (3) not related to a caldera collapse after all. Here, we study the submerged portion of the caldera, which has favored a marine depositional setting and, thus, represents an ideal location for the reconstruction of its formation history, utilizing multichannel seismic data. Volcanic deposits and edifices were seismically distinguished from sedimentary successions, and the stratigraphy could be refined and extended back to the Campanian Ignimbrite eruption at ~39 ka. High-resolution multichannel reflection seismic data revealed the existence of a nested-caldera complex formed during the CI eruption at ~39 ka and the more recent NYT eruption at ~15 ka. A ring-fault bounding an inner caldera collapse structure was clearly imaged. It appears that this inner ring-fault was initially activated during the CI caldera collapse and later reactivated during the NYT caldera collapse with different amounts of subsidence. The NYT caldera probably formed during an asymmetrical collapse with a maximum subsidence of ~75 m in the offshore portion. The vertical displacement related to the CI caldera collapse may be significantly larger. The submerged caldera depression accommodates post-eruption sediments. Within this high-resolution archive, two major unconformities developed at ~8.6 ka and 5 ka, when resurgence-related uplift exceeded the rate of sea-level rise concurrent with the emersion of the La Starza terrace. A previously unknown post-collapse submarine volcanic mound located between Nisida Island and Nisida Bank probably formed between 4.8 and 3.7 ka. Also, the Penta Palummo Bank appears to be constructed of at least two monogenetic volcanic edifices, the Penta Palummo volcano formed at ~100 ka and a younger mushroom-shaped unit formed between 39 and 15 ka. The main outcome of this study is a conceptual evolutionary model, providing novel insights on the formation of the Campi Flegrei nested caldera in the course of two large-scale eruptions (CI and NYT) with associated caldera collapses along mutual (i.e. reactivated) faults and subsequent caldera resurgence. As both the genesis and subsurface architecture of the Campi Flegrei caldera are still hotly debated topics in literature, our discoveries can be regarded as a substantial advancement in the understanding of the Campi Flegrei volcanic area.

Description: The Coroglio tuff cliff, having an approximative surface of 35*10^3 m^2 (140m high and 250m wide), represents a unique geophysical field laboratory. The Coroglio coastal cliff, located in Naples, prevalently faces the Pozzuoli Bay (Tyrrhenian Sea) with a SW orientation and it is subject to very variable weather condition. The cliff surface is characterized by the presence of several fractured welded tuff and rock blocks. In order to monitor the dynamic behaviour of the site, a tri-axial velocimeter has been installed on the Coroglio tuff cliff since 2015. It was located on the cliff free surface at a height of 90.0 meters. The scope is to record vibrations propagating in the medium and to analyse a possible correlation with natural events and/or anthropic activities occurring in the area. This would provide, in principle, the possibility of detecting a typical frequency response for the cliff. The seismic sensor has been set to record minimum and maximum values, recorded every 60 seconds on each component. Here we present the maximum absolute velocity values recorded in a 3-years period (July 2015 - July 2018), resulting in 4320 values each day.

Description: Opening of fractures and deformation of rock blocks can lead to potentially hazardous rock failures on coastal cliffs. Here we present a time series of ground deformation measurements within selected tuff blocks located at the Coroglio coastal cliff (Naples) in Italy, over a 4-year period (Dec 2014-Oct 2018). The Coroglio cliff is 140 m high and 250 m wide, and is exposed towards the SW, facing the Pozzuoli Bay (Tyrrhenian Sea). The cliff rockface is represented by fractured welded tuff (Neapolitan Yellow Tuff fm.), and includes several rock fronts exceeding 50 m in height. Measurements were acquired along fractures and stratal discontinuities bounding the selected unstable tuff blocks, in order to assess the pattern and magnitude of block deformations (fracture opening and block rotational and/or traslative movements) and their evolution through time. The monitoring system is composed of 8 crackmeters and 2 tiltmeters equipped with internal thermometers, that have been set with a sampling rate of one measurement each 30 minutes, resulting in 48 measurements per day.

Description: Weather data monitoring is ongoing since 2013 in a network of three sites located in the Campi Flegrei volcanic area, near Naples (Italy) in the framework of the MONICA (Innovative Monitoring of Coastal and Marine Environment) Project. The aim of this activity is to acquire time series to analyze the influence of meteorological factors on geomorphological coastal processes, such as cliff retreat, landslides and beach erosion. The uploaded dataset includes data (temperature, relative humidity, wind, barometric pressure and rain) acquired at the Bacoli automatic weather station(model: DAVIS Vantage Pro2 wireless) during the period Dec. 2013 - Oct. 2018. Automatic data transfer from the weather station to the ISMAR-CNRprocessing center of Naples is performed by an internet LAN connection.

Description: Weather data monitoring is ongoing since 2013 in a network of three sites located in the Campi Flegrei volcanic area, near Naples (Italy) in the framework of the MONICA (Innovative Monitoring of Coastal and Marine Environment) Project. The aim of this activity is to acquire time series to analyze the influence of meteorological factors on geomorphological coastal processes, such as cliff retreat, landslides and beach erosion. The uploaded dataset includes data (temperature, rain, wind, barometric pressure and humidity) acquired at the Capo Posillipo automatic weather station (model DAVIS Vantage Pro2 wireless) during the period Dec. 2013 - Oct. 2018. The station is located in the western sector of the urban area of Naples (Italy). Automatic data transfer from the weather station to the ISMAR-CNR processing center, located in the Naples harbor, is routinely performed via an Internet LAN connection.

Description: Weather data monitoring is ongoing since 2013 in a network of three sites located in the Campi Flegrei volcanic area, near Naples (Italy) in the framework of the MONICA (Innovative Monitoring of Coastal and Marine Environment) Project. The aim of this activity is to acquire time series to analyze the influence of meteorological factors on geomorphological coastal processes, such as cliff retreat, landslides and beach erosion. The uploaded dataset includes data (temperature, rain, wind, barometric pressure and relative humidity) acquired at the Denza automatic weather station (model DAVIS Vantage Pro2 wireless) during the period Jan. 2019 - Dec. 2019. Automatic data transfer from the weather station to the ISMAR-CNR processing center of Naples is performed by an internet LAN connection.