Experimental evidence for an ascending microflow of geogas in the ground

A microflow of free ascending gas has been observed in 26 out of 30 tested boreholes at three different sites. The flow rates vary between 60 × 10⁻⁴ and 4 cm³/min m² horizontally projected borehole area. Sampling has been made in ground boreholes as well as in holes drilled downwards from the lowest levels in two mines. The composition of the gas varies considerably. The main components of the gas are nitrogen, argon, oxygen and methane. Traces of heavier hydrocarbons are observed. At the site of the ground holes, only traces of methane are observed. In all sampled holes the existence of free oxygen is observed. The nitrogen/argon quotient is close to the atmospheric quotient in all sampled holes, indicating a partly atmospheric origin of the gas. The existence of methane and traces of heavier hydrocarbons indicates the existence of a second source.     

Grand canyon—a quantitative approach to the erosion and weathering of a stratified bedrock

A new method is proposed for solving a differential equation arising from weathering-limited development of a valley. Allowance is made for horizontal stratification and overhang can be allowed to develop. The model is applied to the Grand Canyon and comments are included on its relevance.     

Composition of low energy cosmic radiation from silicon to nickel

The charge composition of the cosmic radiation for the elements withZ14 has been studied in a stack of nuclear emulsions exposed at Fort Churchill in July 1967. Particles stopping in the stack have been measured with a nuclear track photometer to determine the charge. Relative abundances are given for the elements silicon to nickel and comparison is made with other investigations.     

Lateglacial ice dynamics of the Cordilleran Ice Sheet in northern British Columbia and southern Yukon Territory: retreat pattern of the Liard Lobe reconstructed from the glacial landform record

The Liard Lobe formed a part of the north‐eastern sector of the Cordilleran Ice Sheet and drained ice from accumulation areas in the Selwyn, Pelly, Cassiar and Skeena mountains. This study reconstructs the ice retreat pattern of the Liard Lobe during the last deglaciation from the glacial landform record that comprises glacial lineations and landforms of the meltwater system such as eskers, meltwater channels, perched deltas and outwash fans. The spatial distribution of these landforms defines the successive configurations of the ice sheet during the deglaciation. The Liard Lobe retreated to the west and south‐west across the Hyland Highland from its local Last Glacial Maximum position in the south‐eastern Mackenzie Mountains where it coalesced with the Laurentide Ice Sheet. Retreat across the Liard Lowland is evidenced by large esker complexes that stretch across the Liard Lowland cutting across the contemporary drainage network. Ice margin positions from the late stage of deglaciation are reconstructed locally at the foot of the Cassiar Mountains and further up‐valley in an eastern‐facing valley of the Cassiar Mountains. The presented landform record indicates that the deglaciation of the Liard Lobe was accomplished mainly by active ice retreat and that ice stagnation played a minor role in the deglaciation of this region. Copyright © 2013 John Wiley & Sons, Ltd.     

A possible mechanism for the injection of particles into a cosmic ray acceleration region

The composition of the nucleonic component of the primary cosmic radiation has been compared with the natural abundance of the elements. A normalized quotient between the abundance of an element in the radiation and in nature was found to be approximately equal toZ , whereZ is the atomic number and is a constant approximately equal to one. The observed excess of the heavy elements can be expected in the radiation if the selection of the cosmic ray particles is performed by ionization through fast electron or proton impacts on neutral matter having normal composition. Such a selection mechanism may act in regions in space where fast moving thin plasma clouds collide with clouds of neutral matter. A source model in which the plasma clouds originate in Type II supernova explosions is discussed.     

Further evidence for a cosmic ray selection mechanism

A comparison has been made between the overabundance of heavy elements in the primordial cosmic radiation and the cross-section for ionization by charged particle impacts. It is found that there is evidence that this type of ionization is important for the selection of cosmic ray particles.     

Inequalities, institutions, and forest commons

This paper contributes to a growing literature on the commons that examines the relationship between inequality and commons outcomes. Our analysis of evidence on forest commons outcomes in 228 cases from South Asia (India and Nepal), East Africa (Kenya and Uganda) and Latin America (Mexico and Bolivia) suggests that local governance and collective action matter in shaping how socioeconomic inequalities affect forest conditions. In particular, we find that both inter-group and intra-group economic inequalities have consistently negative effects on forest outcomes, but that effectively functioning local institutions for collective action dampen the negative effect of inter-group inequality on forest outcomes.     

Boron substitution in diopside evaluated through 11B nuclear reaction analysis

 Nuclear reaction analyses on boron in flux-grown Me³⁺- and Na⁺-doped diopside crystals utilising the ¹¹B(p,2α)⁴He reaction in conjunction with EMP analyses for major elements and optical absorption spectroscopy for determination of Me-valence state distributions show that appreciable amounts of B may enter the diopside lattice in crystals produced in Na₂B₄O₇ fluxes. The results indicate that the substitution ^[6]Me^3+[4]B^3+[6]Mg²⁺ ₋₁ ^[4]Si⁴⁺ ₋₁ operates in the present diopside samples in addition to the coupled substitution ^[6]Me^3+[8]Na^+[6]Mg²⁺ ₋₁ ^[8]Ca²⁺ ₋₁. The specific NRA technique applied allows for quantitative, high resolution (ca. 5 μm) B analyses at ppm level as well as high-resolution and high-contrast imaging of B-concentration patterns in minerals. The estimated detection limit and relative error of the B analyses are 10 ppm and 5–10%, respectively. Received: 20 September 1999 / Accepted: 6 June 2000     

Isotopic composition of primary cosmic-ray nitrogen and oxygen with consequences for source models

An experimental investigation of the isotopic composition of cosmic-ray nitrogen and oxygen is reported. The detector is a stack of nuclear emulsions exposed at about 3 g cm^–2 atmospheric depth. The mass determinations are based on photometric track width measurements on stopping nuclei. The standard deviation of the mass measurements is 0.46 AMU for nitrogen and 0.50 AMU for oxygen. The energy of the measured nuclei falls in the interval 220–450 MeV nucleon^–1 at the top of the atmosphere.The measured isotopic quotients have been extrapolated to near interstellar space with standard methods. The extrapolated quotients are¹⁵N/N=0.34±0.10,¹⁷O/O=0.02±0.03,¹⁸O/O=0.07±0.03. The nitrogen quotient extrapolated to the cosmic-ray source shows that the nitrogenoxygen abundance ratio is approximately the same in the source as in the solar system. The result has been compared with different hypotheses about the source composition and is found to be in best agreement with a hypothesis which states that source matter has approximately the composition of the solar system and that a selection mechanism, which depends on the atomic properties of the elements, is working in the source.