Panarea NatLab (IT1.3)

Panarea is a natural laboratory where thermo-magmatic CO2 is leaking at substantial rates from the seafloor at water depths ranging from 5 to 30 m. The majority of this CO2 is released in an area between two islets located 3 km to the east of Panarea (Lisca Bianca and Bottaro). This natural CO2-release field (c. 3 km2 ) has been active for centuries, with gas emanating from a series of NW-SE and NE-SW trending fractures (Fig.1).

This natural laboratory provides the opportunity to study gas migration in different structural and geological settings. It can be used to study the ascent of CO2 through sedimentary strata, to decipher the dynamics of gas bubble and droplet plumes, to understand the impact of CO2 on benthic organisms and marine ecosystems, and to test and improve CO2 monitoring techniques. Due to the unique characteristics of this site, the Italian Ministry of University and Research (MIUR) financed the setting up of a permanent laboratory, which offers logistical and scientific support to the researchers utilising the site.

The infrastructure is organized in two floors and included wet and dry laboratories equipped with scientific instrumentations for multidisciplinary studies in the field of physical, chemical, biological and geological sciences. In detail, at the moment, the laboratories are equipped with all the scientific instrumentations needed to assess changes in the carbonate system (spectrophotometer, pHmeter, titrator) along the water column, but also to observe impacts on the living communities and their structures (inverted, epifluorescence, Scanning Electron microscopes and stereomicroscope, Fig. 2).  

The meteorological station provides real-time data on weather and atmospheric CO2 concentration. For field observations and measurements, among the others, Benthic chamber and CISME (Community In Situ MEtabolism) to measure dissolved benthic fluxes and metabolism in situ and a BOOMER for geophysical acquisitions are also available.

OGS is the responsible of this infrastructure and in collaboration with other research institutes and universities (such as the University of Rome, La Sapienza), manages the permanent laboratory, making available the longterm series of multidisciplinary data collected at Panarea and offering logistical and scientific support to the researchers utilising the site. The on land installation (Fig.2) is close to the loading wharf and contains about 90 mq of laboratory space, which are fitted out for general-purpose and dedicated use, and several outside open spaces that can accommodate a variety of shifting needs and equipment. Scientists also have access to a well-equipped computer and electronics lab. The on land installation will also be equipped to maintain, calibrate and real time connect the permanent sensor network, which will be installed in correspondence of the natural CO2 leakages.

From the beginning of 2020, thanks to the PON infrastructure project IPANEMA, the laboratory is being implemented with new and highly technological instrumentations. On-land tools will improve the quality, quantity and type of the analyses that could be carried out in the laboratory, focusing on chemical and microbiological data, strongly important to understand the effects of CO2 leakage on the whole marine ecosystem. Moreover, the acquired off-shore instrumentations will provide new insight into the geological and geochemical dynamics, but also in physiological responses of the marine organisms. Three types of highly innovative instruments, aimed at the integrated and high-tech monitoring of gaseous emissions, extremely versatile and functional for multidisciplinary research will be also acquired: an AUV (Autonomous Underwater Vehicle) for the characterization of water and sediment; a ROV (Remotely Operated Vehicle) for background inspection and analysis, including sampling; a UAV (Unmanned Aerial Vehicle), or drone, for the characterization of the coastal area and of surface gas emissions. In addition, the sensors at sea will be implemented by setting up a new submarine observatory that will host multidisciplinary sensors (chemical, physical, oceanographic and geophysical) for the acquisition of measurements in continuous and synchronized mode or referenced over time according to a single time signal. 

In the early 1980’s researchers began to conduct gas geochemistry surveys of the area showing that the system was relatively stable in both gas chemistry (e.g. 98% CO2, 1.7% H2S plus other trace gases) and flux rates (7-9 x 106 l/d). On November 2 and 3, 2002, a gas outburst event increased the total gas flow rate by about 2 orders of magnitude (4 x 108 l/d), with large volumes of gas reaching the water surface. Flux rates began to decrease towards pre-outburst conditions about 3 months after the event. The majority of fluid release points are gas only, although various points also release water of different origin, ranging from geothermal to seawater endmembers that are mixed to variable degrees. Based on the range of depths and relatively high and persistent gas flow rates, the occurrence of both gas only and gas-water seepage, and its close proximity to shore, Panarea represents an exceptional location to study natural processes and impacts related to shallow seabed CO2 leakage. This site has been studied in the framework of several European projects with an integrated physical chemical, biological approach for a more complete (and realistic) understanding of the possible consequences of a leak from a CO2 storage site into the overlying water column.