A 20‐ka climate record from Central Himalayan loess deposits

The southwest monsoon that dominated Central Himalaya has preserved loessic silt deposits preserved in patches that are proximal to periglacial areas. The occurrence of such silts suggests contemporary prevalence of cold and dry northwesterly winds. Field stratigraphy, geochemistry, mineral magnetism, infrared stimulated luminescence (IRSL) and radiocarbon dating has enabled reconstruction of an event chronology during the past 20 ka. Three events of loess accretion could be identified. The first two events of loess deposition occurred betweem 20 and 9 ka and were separated by a phase of moderate weathering. Pedogenesis at the end of this event gave rise to a well‐developed soil that was bracketed around 9 to > 4 ka. This was followed by the third phase of loess accretion that occurred around 4 to > 1 ka. Episodes of loess deposition and soil formation are interpreted in terms of changes in the strength of the Indian southwest monsoon. Copyright © 2005 John Wiley & Sons, Ltd.     

Fundamental reference systems; Past,present, and future

The present fundamental reference system is defined by the FK5 Fundamental Reference Catalog and the associated IAU Resolutions of 1976 through 1982. The past is defined to be what preceded the present fundamental reference system and future is defined to be what ever will come after it. The resulting characteristics of the different fundamental reference systems are considered from the aspects of the observational data, the computational methods, and the underlying theories. Having developed an understanding of these operational fundamental reference systems, the desired properties of the ideal fundamental reference system are presented. Finally, some questions concerning the future fundamental reference system are presented.     

Muon flux at the geographical South Pole

The muon flux at the South Pole was measured for five zenith angles, 0°, 15°, 35°, 82.13° and 85.15° with a scintillator muon telescope incorporating ice Cherenkov tank detectors as the absorber. We compare the measurements with other data and with calculations.     

Red-violet asymmetry in pearl satellites' birth

A high resolution numerical sonagram of Pc-1 magnetic record has shown that single narrow lines of Pc-1 spectra produce lower frequency (“red-shifted”) satellite lines more than twice as often as their higher frequency (“violet”) counterparts. The violet satellites usually emerge only when at least two ancestor lines are present simultaneously.     

Is IRAS 03134 + 5958 a Herbig-Haro object?

The source IRAS 03134 + 5958 identified by Iyengar & Verma (1984) on the Palomar Observatory Sky Survey (POSS) prints with a nonstellar optical object with [P – R]≃ 5.3 ± 1.5 is near the edge of Lynds dark cloud No. 1384 and is either embedded in or behind the cloud. The galactic latitude of this source (b ^II = 2‡.3), its positionvis-a-vis the Lynds dark cloud, its nonstellar appearance, high [P – R] colour and its far-infrared spectrum, all suggest the possibility of its being a Herbig-Haro (HH) object. To test this possibility we undertook measurements of its proper motion and variability (two of the characteristic properties of HH objects). These yield μ_a = (3.6 ± 2.3) arcsec/century and μ_δ= (−1.2 ± 2.0) arcsec/century for its proper motion. The source reveals large variation in brightness between 1950 and 1954. Optical line studies of the source are required to confirm its classification as an HH object.     

A model for the constant-head pumping test conducted in vertically fractured media

An analytical model for the constant-head pumping test is developed for a partially penetrating well that has a finite thickness skin, and intersects a single vertical fracture. In the model, the fracture is fully confined and flow occurs only in the fracture. The model is developed using Laplace transform and finite Fourier transform methods. The model is to be used for analysing well test data from vertically fractured media and for verifying numerical models. Dimensionless curves are used to study the effects of a finite thickness skin and a partially penetrating wellbore. In the presence of a finite thickness skin, or a partially penetrating wellbore, a typical flow response for the constant-head pumping test has three distinct periods of flow corresponding to small-, intermediate- and large-time. Small- and large-time approximations are presented for the model. For tests where the wellbore is fully penetrating, or the partial penetration ratio is known, these approximations can be used to analyse field data.     

Drumlin formation in Southern Anglesey and Arvon,Northwest Wales

This is a study of Late Devensian drumlins formed in southern Anglesey and Arvon, northwest Wales. This area was affected by ice sheet coalescence when the Welsh ice sheet met with the lrish Sea ice sheet, and drumlins were formed once the two had coalesced. It is suggested that the drumlins were the result of net subglacial soft-bed erosion, and that they represent more resistant cores within the subglacial deforming layer. The drumlins have either gravel or till cores, and where the core was deformable, large-scale compressive glaciotectonic structures were seen (e.g. Dinas Dinlle) with local subglacial compression of –59%. Where the cores were more resistant (e.g. Lleiniog) these were not deformed but remained as more competent masses within the deforming layer. It is suggested that the less competent material flowed around the cores, some remaining as a thin carapace, but most of the material being removed down glacier, leaving the drumlins as erosional remnants. In northwest Wales there is a multi-till sequence that traditionally has been interpreted as having been deposited as the result of separate ice-sheet advances and retreats. However, in this study, it is suggested that the different tills were deposited as the result of ice-sheet coalescence, and that sites such as Dinas Dinlle do not show evidence of a major readvance in the retreat of the Devensian ice, but are indicative of continuously changing conditions within the subglacial deforming bed.     

The Relationship of Green-Line Transients to White-Light Coronal Mass Ejections

We report observations by the Large Angle Spectrometric Coronagraph (LASCO) on the SOHO spacecraft of three coronal green-line transients that could be clearly associated with coronal mass ejections (CMEs) detected in Thomson-scattered white light. Two of these events, with speeds >25 km s^-1, may be classified as ‘whip-like’ transients. They are associated with the core of the white-light CMEs, identified with erupting prominence material, rather than with the leading edge of the CMEs. The third green-line transient has a markedly different appearance and is more gradual than the other two, with a projected outward speed <10 km s^-1. This event corresponds to the leading edge of a ‘streamer blowout’ type of CME. A dark void is left behind in the emission-line corona following each of the fast eruptions. Both fast emission-line transients start off as a loop structure rising up from close to the solar surface. We suggest that the driving mechanism for these events may be the emergence of new bipolar magnetic regions on the surface of the Sun, which destabilize the ambient corona and cause an eruption. The possible relationship of these events to recent X-ray observations of CMEs is briefly discussed. Supplementary material to this paper is available in electronic form at http://dx.doi.org/10.1023/A:1004981125702