• Western Mediterranean
• Sulmona Basin
• stable isotopes
• MIS 11
• lacustrine succession
• paleoclimate

Earth’s climate during the Quaternary period (~ 2.6 MA to present) has been characterized by fluctuations at different time scales, globally expressed as alternating cold and warm stages.
In the 1941, Milutin Milankovich supposed that variations in Earth’s orbital parameters (eccentricity, axial tilt and precession of the equinoxes) resulted in seasonal and latitudinal distribution changes of the solar radiation reaching the Earth, making the global climate to oscillate between cold and warm stages (called glacial and interglacial respectively).
Nowadays we are experiencing an interglacial period, the Holocene (ca. 11.6 ka to present) whose later part is interested by anthropogenic greenhouse gas (GHG) emissions, that can influence the future evolution of climate.
In recent years, the main challenge that the scientists have to deal with is the so-called “global warming”.
The study of past interglacial periods is important to understand our present and future climate, because they represent natural reference intervals for evaluating timing and progression of the present warm stage.
Currently, researchers are focusing their attention on interglacials which took place under orbital configuration similar to that of the Holocene, such as those corresponding to Marine Isotope Stage (MIS) 11 and MIS 19, because enhancing knowledge about their duration and internal dynamics could be useful to better understand the background of natural climate variability during warm intervals, and can help to predict how the anthropogenic factors will impact in the natural sequence of events (Tzedakis et al., 2009).
Within this framework, and in order to improve the existing knowledge on interglacial processes and future climate evolution, this thesis aims to reconstruct at high temporal resolution the hydrological and environmental changes occurred in central Italy during the warm interval corresponding to the interglacial portion of Marine Isotope Stage 11(about 420-370 ka)
To achieve this purpose, two scientific campaigns were carried out in the Sulmona Basin, Abruzzo, in which has developed a lacustrine succession.
During the first campaign (March 2018) two sediment cores were retrieved, whereas the second (April 2018) consisted of sampling of several outcropping contiguous sections, anchored to each other using volcanic ash layers (tephra) interbedded within the lacustrine sediment as correlation markers.
In this way, a continuous sediment succession spanning the lacustrine interval deposited during the MIS 11 was obtained.
To reconstruct the climate and environmental changes of MIS 11, a multiproxy approach was employed by investigating sediment properties like the stable isotope composition of lacustrine carbonates (δ18O and δ13C) by means of Isotope Ratio Mass Spectrometry (IRMS), mineralogical composition through X-Ray Diffraction (XRD), major and minor elements composition through X-Ray Fluorescence analyses (XRF), total organic and inorganic carbon content (TOC and TIC), total sulfur (TS), total nitrogen (TN), grain size analyses.

The interpretation of the results obtained through these anlyses allowed the identification of several hydrological and environmental changes, whose significance is ensured by their simultaneous occurrence in all the investigated proxies.
The hydrological fluctuations recognised by the analysis of the δ18O record, which is principally driven by the “amount effect”, seems to control the other environmental variations interesting the lake system and its catchment. On the basis of these precipitation changes, we subdivide our record into four main intervals:
 424-421 ka  Termination V, i.e the transition between the cold and dry climate occurred during MIS 12 and the interglacial conditions established in the following MIS 11. This period was characterised by the highest amplitude variations of all the proxies, coherently indicating enhanced precipitation and productivity, higher lake level and reduced catchment erosion.
 421-414,5 ka  the warmest and wettest interval detected along our succession, which represents the most favourable climatic conditions taking place in the Sulmona Basin during the peak interglacial of MIS 11.
During this phase of higher precipitation, the level and the area of the lake increased, leading to the deposition of finer particles. The clastic input to the lake was lower because of a considerable expansion of arboreal vegetation, which hampered the soil erosion. The intense activity of this last one and the re-activation of the karst system led to a larger nutrients supply to the lake, that, in association with higher temperatures, favoured the primary productivity and the calcite precipitation.
This interval was however characterised by the occurrence of a first drier event (SUL-DE1) between ca. 418,5 and 417,8 ka.
 414,5-407 ka  following a significant transition toward higher δ18O values, probably pointing at reduced seasonality, this interval represents a stable phase, because it was not interested by remarkable changes. Nevertheless, the primary productivity was characterised by a decreasing trend between 411 and 407 ka, which could be indicative of a lowering in water temperature.
 407-395 ka  the last interval of our succession is marked by the occurrence of two events, named SUL-DE2 and SUL-DE3 (407-404 ka and 403-401,5 ka, respectively), which were characterised by a prominent return to drier conditions.
During these two phases, the lower amount of precipitation led to a scarce development of arboreal vegetation and a consequent enhanced soil erosion, which caused an increased transport of clastic material to the lake. Furthermore, the lake level and area diminished, as witnessed by coarser grains deposited within the lake and by the occurrence of several “Dreissena polymorpha” layers. Finally, because of lower temperatures and deteriorated nutrients supply, the primary productivity of the lake was lower.

The general agreement between our record and that from Lake Ohrid (Southern Balkans, Kousis et al., 2018) provides evidences of the significance of the hydrological and environmental changes detected at Sulmona Basin in the framework of Mediterranean climate. Indeed, the variations in the amount of precipitation identified in the δ18O time-series are in good agreement with the vegetation dynamics at Lake Ohrid, given its dependence on temperature and water availability. Particularly, the drier events recorded in our record (SUL-DE2 and SUL-DE3) matches two prominent forest contractions occurred at Lake Ohrid (LO-11-1 and LO-11-2).
Although a different timing of the events (probably related to our preliminary age model), the strict similarity between the Sulmona hydrological variability and the vegetation changes detected at Site U1385 (Iberian margin, Oliveira et al., 2016) allows us to identify the strong teleconnection between central Mediterranean hydrology and North Atlantic conditions. This explains the occurrence of SUL-DE2 and SUL-DE3 as principally driven by cooler conditions in the North Atlantic, which led to decreased evaporation and consequent diminished moisture advection toward the Mediterraean.
Finally, the potential coincidence of SUL-DE2 with a reduced primary productivity at Lake El’Gygytgyn (Melles et al., 2012) and with the expansion of cold-tolerant species at Lake Baikal (Prokopenko et al., 2010), could indicate the relation between the hydrological deficiency at Sulmona Basin and a regional cooling, extended beyond the North Atlantic.