Unravelling the moisture sources of the Alpine Glaciers using tunnel valleys as constraints

A lack of archives has impeded reconstructions of moisture pathways for past glaciations in the European Alps. Here, we focus on the confluence area of two palaeoglaciers in the Swiss Plateau that were sourced on the northern (Aare glacier) and southern sides (Valais glacier) of the European Alps. We mapped tunnel valleys in the region using a drilling database, based on which we inferred the relative extent of each glacier c. 270 ka ago when the valleys were formed. We then compared this situation with that of the LGM. We found that, while the Valais glacier expanded farther into the foreland than the Aare glacier during the LGM, the opposite was the case c. 270 ka ago. We also found that LGM glaciers were non-erosive in the distal foreland. These contrasts in extents and erosional efficiencies imply differences in moisture pathways between the LGM and the time when the tunnel valleys were formed.

Olive growing in the arid valleys of Northwest Argentina (provinces of Catamarca, La Rioja and San Juan)

En este artículo se describe la situación del olivar en las provincias argentinas de Catamarca, La Rioja y San Juan.

Structure of Alluvial Valleys from 3-D Gravity Inversion: The Low Andarax Valley (Almería, Spain) Test Case

This paper presents a gravimetric study (based on 382 gravimetric stations in an area about 32 km2) of a nearly flat basin: the Low Andarax valley. This alluvial basin, close to its river mouth, is located in the extreme south of the province of Almería and coincides with one of the existing depressions in the Betic Cordillera. The paper presents new methodological work to adapt a published inversion approach (GROWTH method) to the case of an alluvial valley (sedimentary stratification, with density increase downward). The adjusted 3D density model reveals several features in the topography of the discontinuity layers between the calcareous basement (2,700 kg/m3) and two sedimentary layers (2,400 and 2,250 kg/m3). We interpret several low density alignments as corresponding to SE faults striking about N140?145°E. Some detected basement elevations (such as the one, previously known by boreholes, in Viator village) are apparently connected with the fault pattern. The outcomes of this work are: (1) new gravimetric data, (2) new methodological options, and (3) the resulting structural conclusions.

An analysis of installation of submarine pipelines

There are different methods of construction of outfall pipelines, all of them have to solve the problem of placing a tube over a known location in sea bed. This process has sometimes to be done in difficult conditions as waves, current or depths greater than 30 metres, where a diver cannot go safely beyond. Also the placement of the pipeline must be carried out without any damage to the tube, therefore a close control of the deflections and stresses in the structure must be performed. The importance of this control should be not diminished because a damage during the construction would imply a very difficult and expensive repair, that should be avoided with a proper design of the construction process. This paper is focused in the analysis of the tube during its placement according to a very well known construction method consisting in placing the tube from a boat, where all the connections between consecutive tube segments are performed, and also the whole process is controlled. This method is used for outfall as well as offshore pipelines, and it will be described in Section 2

(Table 1) Soil density and concentration of 10Beryllium and 26Aluminium in samples from two ash deposits in the McMurdo Dry Valleys

The McMurdo Dry Valleys, Antarctica (MDV) are among the oldest landscapes on Earth, and some landforms there present an intriguing apparent contradiction such that millions of years old surface deposits maintain their meter-scale morphology despite the fact that measured erosion rates are 0.1-4 m/Ma. We analyzed the concentration of cosmic ray-produced 10Be and 26Al in quartz sands from regolith directly above and below two well-documented ash deposits in the MDV, the Arena Valley ash (40Ar/39Ar age of 4.33 Ma) and the Hart ash (K-Ar age of 3.9 Ma). Measured concentrations of 10Be and 26Al are significantly less than expected given the age of the in situ air fall ashes and are best interpreted as reflecting the degradation rate of the overlying sediments. The erosion rate of the material above the Arena Valley ash that best explains the observed isotope profiles is 3.5 ± 0.41 x 10**-5 g/cm**2/yr (~0.19 m/Ma) for the past ~4 Ma. For the Hart ash, the erosion rate is 4.8 ± 0.21 x 10**-4 g/cm**2/yr (~2.6 m/Ma) for the past ~1 Ma. The concentration profiles do not show signs of mixing, creep, or deflation caused by sublimation of ground ice. These results indicate that the slow, steady lowering of the surface without vertical mixing may allow landforms to maintain their meter-scale morphology even though they are actively eroding.

(Table 8.2, Page 178) Annotated record of the detailed examination of Mn deposits from submarine photographs acquired by the R/V Vityaz in the Pacific Ocean

Prof. H. H. W. Menard has brought together nearly all that was known of the Pacific geology in the early 1960s. His book contains a particular chapter on manganese nodules giving a stimulating review of the features and processes known to govern their distribution and chemical composition.

Worldwide submarine challenges /

Mode of access: Internet.

Meeting the submarine challenge : a short history of the Naval Underwater Systems Center /

Shipping list no.: 97-0340-P.

Status of the Trident submarine and missile programs, Department of the Navy : report to the Congress /

Publication date stamped on cover.