ALBERT

Description: The Mediterranean region is expected to be highly impacted by global warming. To better understand and predict shifts in its current climate system, climate time series covering seasonal-to-century scale climate variability are needed. Here we provide a dataset containing a high-resolution reconstruction of autumn precipitation variability for the Central Pyrenees that spans the 1500-2002 CE period. This dataset is based on calcite sublayer width of varved sediments of lake Montcortès. Sediment cores MON12-3A-1G and MON12-2A-1G were retrieved from the deepest basin of the lake. Large-scale thin sections of sediment (120 mm X 35 mm) were extracted and calcite varve sublaminae counted and characterised. The age-depth model was built by combining varve counting and radiometric dating (210Pb, 137Cs and 14C). Long-term trend of the raw calcite width series was removed with a low pass filter by fitting a cubic smoothing spline of 67% of the series length. To find out how well the smoothed calcite series and instrumental regional precipitation match up with each other, correlation and cross correlation methods were applied. Highest correlation values were obtained with autumn precipitation anomalies for the entire calibration period (1900-2002) and for the two halve subperiods (1910–1956 and 1957–2002). The applied statistical tests yield highly significant results. The obtained regression model explained 15.5% (R2-value for the full calibration period) of the September to November precipitation variability. The obtained transfer function allowed inferring past autumn precipitation from calcium carbonate sublayer thickness at annual resolution. The reconstructed series (PPT-SON) provides the first estimations of regional autumn precipitation shifts in the Central Pyrenees since 1500 CE.

Description: Phytoplankton community composition was assessed using chemotaxonomic pigments (including all chlorophyll types, accessory and photoprotective pigments) measured with high performance liquid chromatography (HPLC). Water samples from 7 depths spanning the euphotic zone were collected using a CTD-rosette during the five Lagrangian experimental cycles conducted during Salp Particle expOrt and Ocean Production (SalpPOOP), from October to November 2018 in the vicinity of the Chatham Rise (New Zealand). Depths varied according to experimental cycle, as it was adjusted based on PAR profiles to span the depth to 0.1% of surface irradiance. Chemotaxonomic pigments of phytoplankton in the water column were filtered onto GF/F filters (2L), then immediately flash-frozen in liquid nitrogen, and shipped frozen to Instituto Español de Oceanografía, Centro Oceanográfico de Gijón, where they were extracted for High-performance liquid chromatography (HPLC) analyses following established protocols (doi:10.4319/lom.2014.12.46). For this study, 2 profiles from each experimental cycle were analyzed, and vertically integrated to obtain areal estimates for each cycle. Pigment contributions were normalized by total chlorophyll a (Chl a) to account for potential losses and low yield, and are thus presented as integrated percentages per cycle. These proportions do not always sum to 100 because ancillary pigments/other compounds that cannot be positively identified are not included.

Description: Water samples from 7 depths spanning the euphotic zone were collected using a CTD-rosette during the five Lagrangian experimental cycles conducted during Salp Particle expOrt and Ocean Production (SalpPOOP), from October to November 2018 in the vicinity of the Chatham Rise (New Zealand). Depths varied according to experimental cycle, as it was adjusted based on photosynthetically active radiation (PAR) profiles to span the depth to 0.1% of surface irradiance. The physiology of the phytoplankton community was evaluated using the Mini-Fire fast repetition rate fluorometer (FRRF), using approximately 5ml per depth. Fv/Fm and reoxidation of Qa-, the first quinone acceptor of PSII, were evaluated using the Mini-Fire FRRF, which provided indications of phytoplankton stress most likely caused by iron-limitation following the procedure outlined in Gorbunov and Falkowski (2020 doi:10.1002/lno.11581).

Description: In the Campeche Knolls, in the southern Gulf of Mexico, lava-like flows of solidified asphalt cover more than 1 square kilometer of the rim of a dissected salt dome at a depth of 3000 meters below sea level. Chemosynthetic tubeworms and bivalves colonize the sea floor near the asphalt, which chilled and contracted after discharge. The site also includes oil seeps, gas hydrate deposits, locally anoxic sediments, and slabs of authigenic carbonate. Asphalt volcanism creates a habitat for chemosynthetic life that may be widespread at great depth in the Gulf of Mexico.

Description: The grain-size distribution of 223 unconsolidated sediment samples from four DSDP sites at the mouth of the Gulf of California was determined using sieve and pipette techniques. Shepard's (1954) and Inman's (1952) classification schemes were used for all samples. Most of the sediments are hemipelagic with minor turbidites of terrigenous origin. Sediment texture ranges from silty sand to silty clay. On the basis of grain-size parameters, the sediments can be divided into the following groups: (1) poorly to very poorly sorted coarse and medium sand; and (2) poorly to very poorly sorted fine to very fine sand and clay.

Description: Grain size of 139 unconsolidated sediment samples from seven DSDP sites in the Guaymas Basin and the southeastern tip of the Baja California Peninsula was determined by sieve and pipette techniques. Shepard (1954) classification and Inman (1952) parameters correlation were used for all samples. Sediment texture ranged from sand to silty clay. On the basis of grain-size parameter, the sediments can be divided into three broad groups: (1) very fine sands and coarse silts; (2) medium- to very fine silts; and (3) clays and coarse silts.

Description: The physical properties of 138 unconsolidated hemipelagic silty clays and turbidites from the mouth of the Gulf of California were analyzed in order to determine their grain size, shear strength, compressional wave velocity, porosity, specific gravity, wet-bulk density, water content, void ratio, and degree of saturation. As at other Deep Sea Drilling Project (DSDP) sites, the wet-bulk density, sonic velocity, and shear strength tended to increase with depth while the porosity and water content decreased in response to increasing compaction. The grain size and clay fraction varied irregularly with depth. The wet-bulk density ranged from 1.34 to 2.58 g/cm**3, while, the shear strength and compressional wave velocity ranged from 0.03 to 1.05 tons/ft.**2 and 1.47 to 4.25 km/s, respectively. The porosity varied between 8 and 79%, while the water content ranged from 28.0 to 175.6%; most samples were effectively 100% saturated. The specific gravity ranged from 1.71 to 3.24 and showed a tendency to be directly related to the wet-bulk density and thus inversely related to porosity. The physical properties of the hemipelagic sediments and turbidites are noticeably different, and the properties of both were modified by diagenesis near the basement.