Catchment characteristics and soil and water chemistry of the San Francisco basin and subbasins, Ecuador

In this study, the Mean Transit Time and Mixing Model Analysis methods are combined to unravel the runoff generation process of the San Francisco River basin (73.5 km**2) situated on the Amazonian side of the Cordillera Real in the southernmost Andes of Ecuador. The montane basin is covered with cloud forest, sub-páramo, pasture and ferns. Nested sampling was applied for the collection of streamwater samples and discharge measurements in the main tributaries and outlet of the basin, and for the collection of soil and rock water samples. Weekly to biweekly water grab samples were taken at all stations in the period April 2007-November 2008. Hydrometric data, Mean Transit Time and Mixing Model Analysis allowed preliminary evaluation of the processes controlling the runoff in the San Francisco River basin. Results suggest that flow during dry conditions mainly consists of lateral flow through the C-horizon and cracks in the top weathered bedrock layer, and that all subcatchments have an important contribution of this deep water to runoff, no matter whether pristine or deforested. During normal to low precipitation intensities, when antecedent soil moisture conditions favour water infiltration, vertical flow paths to deeper soil horizons with subsequent lateral subsurface flow contribute most to streamflow. Under wet conditions in forested catchments, streamflow is controlled by near surface lateral flow through the organic horizon. Exceptionally, saturation excess overland flow occurs. By absence of the litter layer in pasture, streamflow under wet conditions originates from the A horizon, and overland flow.

Undergrowth removal in Salgesch: Soil volumetric water content and temperature time series, hourly time resolution, 2010-2015

In the Salgesch forest in the Canton of Valais in Switzerland, the understory has been removed to test whether effects on pine tree vitality. The data set published here compromises 120 time series of 60 soil temperature and 60 volumetric water content (VWC) sensors (EC-TM and 5-TM) (Decagon Devices, WA, USA) at three soil depth levels (5, 30, 60 cm) employed in the direct vicinity of six control trees and six trees with the undergrowth removed. At the levels 5 and 60 cm, three replications were made whereas 4 replications were made at level 30 cm. Six loggers recorded hourly data since 2010 with 18% gaps or 11% when not considering winter months December, January and February. The figure attached to this repository shows the average VWC and temperature of all measurements within the same depth and treatment specific setting aggregated in a defined time interval and period. In addition to that, the standard deviations are plotted as transparent polygons. In case of insufficient values for calculating standard deviations, the setting specific mean standard deviation of the considered time period are inserted.

Geochemical parameters of sediments and water of the Black Sea, data of Cruise 8 of R/V Vityaz-2

The book presents results of comprehensive geological investigations carried out during Cruise 8 of R/V "Vityaz-2" to the western part of the Black Sea in 1984. Systematic studies in the Black Sea during about hundred years have not weakened interest in the sea. Lithological and geochemical studies of sediments in estuarine areas of the Danube and the Kyzyl-Irmak rivers, as well as in adjacent parts of the deep sea and some other areas were the main aims of the cruise. Data on morphological structures of river fans, lithologic and chemical compositions of sediments in the fans and their areal distribution, forms of occurrence of chemical elements, role of organic matter and gases in sedimentation and diagenesis are given and discussed in the book.

Hydrographic measurements from C.S.S. Hudson Cruise 82-002, Canadian Technical Report of Hydrography and Ocean Sciences No. 118, 112 pp (digital version)

This archive consists of the hydrographic data collected on Cruise 82-002 of C.S.S. Hudson, April 11 to May 2, 1982. 78 stations were occupied on a line running near 48°N from the mouth of the English Channel to the Grand Banks of Newfoundland. Pressure, temperature and salinity were measured by a Guildline digital CTP system. Salinity, dissolved oxygen, silicate, nitrate and phosphate were measured from water samples collected on the CTP upcasts. CTP and discrete bottle data and associated derived parameters are tabulated at standard levels. This is the digital version of the printed report (of 1989, see further details), published in 2006 with the information system Pangaea.

H, O, Sr, and Nd isotope ratios and water, Rb, Sr, Sm, and Nd content of ODP Hole 116-717C and 116-718C samples (Table 2)

Mineralogical and H, O, Sr, and Nd isotope compositions have been analyzed on a set of representative samples from the 17-m.y. section in ODP Leg 116 Holes 717C and 718C. Based on the mineralogical composition of the fraction <2 µm together with the lithogenic-biogenic composition of the fraction >63 µm, the whole section can be subdivided into three major periods of sedimentation. Between 17.1 and 6 m.y., and between 0.8 m.y. to present, the sediments are characterized by sandy and silty turbiditic inputs with a high proportion of minerals derived from a gneissic source without alteration. In the fraction <2 µm, illite and chlorite are dominant over smectite and kaolinite. The granulometric fraction >63 µm contains quartz, muscovite, biotite, chlorite, and feldspars. The 6-to 0.8-m.y. period is represented by an alternation of sandy/silty horizons, muds, and calcareous muds rich in smectite, and kaolinite (50% to 85% of the fraction <2 µm) and bioclastic material. The presence of smectite and kaolinite, as well as the 18O/16O and the 87Sr/86Sr ratios of the fraction <2 µm, imply an evolution in a soil environment and exchanges with meteoric ground water. The ranges of isotopic compositions are limited throughout the section: d18O quartz = 11.7 to 13.3 per mil, 87Sr/86Sr = 0.733 to 0.760 and epsilon-Nd (0) = -17.4 to -13.8. These values are within those of the High Himalaya Crystalline series, and they are considered to reflect this source region. The data imply that, since 17 Ma, this formation has supplied the major part of the eroded material.

Pore water chemistry of sediment core GeoB15101-7 and water chemistry of CTD casts GeoB15101-1 and GeoB15101-6

Submarine brine lakes feature sharp and persistent concentration gradients between seawater and brine, though these should be smoothed out by free diffusion in open ocean settings. The anoxic Urania basin of the Eastern Mediterranean contains an ultra sulfidic, hypersaline brine of Messinian origin above a thick layer of suspended sediments. With a dual modeling approach we reconstruct its contemporary stratification by geochemical solute transport fundamentals, and show that thermal convection is required to maintain mixing in the brine and mud layer. The origin of the Urania basin stratification was dated to 1650 years before present, which may be linked to a major earthquake in the region. The persistence of the chemoclines may be key to the development of diverse and specialized microbial communities. Ongoing thermal convection in the fluid mud layer may have important, yet unresolved consequences for sedimentological and geochemical processes, also in similar environments.