Resolving the enigma of early coastal settlement in the Hawaiian Islands: The stratigraphic sequence of the Wainiha Beach Site in Kaua'i

Archaeological excavation has documented stratified cultural deposits at the Wainiha Beach Site in Kaua'i (Hawaiian Islands), beginning with the occupation of a residential structure dated around A.D. 1030–1400. After about A.D. 1400, the excavated area contains abundant evidence of widespread repeated temporary activities ending in the post‐Contact era (post‐A.D. 1778). The presence of an early permanent residence followed by a later period of temporary activities opposes conventional understanding of a trend from temporary to permanent occupation in similar sites in the Hawaiian Islands. The complete stratigraphic sequence is disclosed here, with reference to formation processes and depositional context of eight major strata documented in a controlled excavation 0.95 m deep. Various human activities (such as digging pits, trampling, etc.) and periodic natural high‐energy events (such as tsunami) appear to have altered the upper portions of underlying deposits. Large sections of the earliest human occupation layer were obliterated, and successive episodes of short‐lived activities created numerous inconsistencies in the stratigraphy. These results have important implications for interpreting the cultural sequence not only at Wainiha but also at other rather enigmatic beach sites in the Hawaiian Islands and elsewhere. © 2004 Wiley Periodicals, Inc.     

Constraints on Jupiters from observations of Galactic bulge microlensing events during 2000

We present observations of eight Galactic bulge microlensing events taken with the 1.0-m Jacobus Kapteyn Telescope (JKT) on La Palma during 2000 June and July. The JKT observing schedule was optimized using a prioritizing algorithm to automatically update the target list. For most of these events we have sampled the light curves at times where no information was available from the OGLE alert team. We assume a point-source point-lens (PSPL) model and perform a maximum likelihood fit to both our data and the OGLE data to constrain the event parameters of the fit. We then refit the data assuming a binary lens and proceed to calculate the probability of detecting planets with mass ratio   q = 10⁻³  . We have seen no clear signatures of planetary deviations on any of the eight events and we quantify constraints on the presence of planetary companions to the lensing stars. For two well-observed events, 2000BUL31 and 2000BUL33, our detection probabilities peak at ∼30 and ∼20 per cent respectively for   q = 10⁻³  and   a ∼ R _E  for a  Δχ²  threshold value of 60.     

Timing of the progress granite,Larsemann hills: Additional evidence for early Palaeozoic orogenesis within the east Antarctic Shield and implications for Gondwana assembly

The Progress Granite is one of numerous S‐type granitoid plutons exposed in the Larsemann Hills region, southwest Prydz Bay, east Antarctica. The granite was emplaced into a migmatitised pelitic to felsic paragneiss sequence during a regional high‐grade transpressional event (D₂) that pre‐dates high‐grade extension (D₃). SHRIMP (II) U‐Pb dating for two occurrences of the Progress Granite from D₂ and D₃ structural domains gives ²⁰⁶Pb/²³⁸U ages of 516.2 ± 6.8 Ma and 514.3 ± 6.7 Ma, respectively. These ages are interpreted as crystallisation ages for the Progress Granite and confirm Early Palaeozoic orogenesis in the Larsemann Hills region. This orogen appears to have evolved during continental convergence and is probably responsible for widespread radiogenic isotopic resetting and the near‐complete exhumation of the adjacent northern Prince Charles Mountains which evolved during a ca 1000 Ma event. The identification of a major Early Palaeozoic orogen in Prydz Bay allows tentative correlation of other domains of Early Palaeozoic tectonism both within the east Antarctic Shield and other, once contiguous, Gondwana fragments and illustrates the potential complexity inherent within intercratonic mobile belts. One such possibility, tentatively offered here, suggests a continuous belt of Early Palaeozoic tectonism from Prydz Bay eastward to the West Denman Glacier region and into the Leeuwin complex of Western Australia.     

Hydrologic modeling of flood conveyance and impacts of historic overbank sedimentation on West Fork Black's Fork, Uinta Mountains, northeastern Utah, USA

This study assesses historic overbank alluvial sedimentation along a low-gradient reach of West Fork Black's Fork in the northern Uinta Mountains, Utah. In this previously glaciated setting, an alluvial floodplain that is approximately 400 m wide by 1500 m long has been modified by the combined effects of valley morphometry and the recent history of clear-cut logging during the late 19th and early 20th Centuries. To quantify the effects on sedimentation and flow conveyance, three natural streambank exposures were sampled and analyzed for nuclear bomb fallout ¹³⁷Cs. The distribution of ¹³⁷Cs within the three profiles suggests that a remnant outwash terrace exerts a first-order control over the deposition of overbank alluvium. Upstream from a constriction in the floodplain caused by the terrace remnant, as much as 40 cm of overbank alluvium has been deposited since the beginning of clear-cut logging. Immediately downstream of that constriction, no evidence exists for any overbank sedimentation during that same period. Vibracore samples and Oakfield soil probe sampling throughout the study reach quantified the geographic extent and thicknesses of the historic alluvial package. Flood conveyance through the study area was modeled using the U.S. Army Corps of Engineers HEC-RAS modeling program. Model simulations were run for modern conditions (using surveyed topography) and for prehistoric conditions (using the modern topography less the historic alluvial package determined by ¹³⁷Cs analyses). Model results indicate that the floodplain constriction caused a significant impediment to flood conveyance at even modest discharges during prehistoric conditions. This promoted ponding of floodwaters upstream of the constriction and deposition of alluvium. This has increased bank heights upstream of the constriction, to the point that under modern conditions 1- to 5-year recurrence interval floods are largely confined within the channel. These results confirm the validity of this new approach of combining ¹³⁷Cs dating of alluvial sediments with HEC-RAS flow modeling to compare flood conveyance along a single stream reach prior to and since an abrupt change in alluvial sedimentation patterns.     

GIS DATA CAPTURE FROM AERIAL PHOTOGRAPHS: A CASE STUDY

A case study at the Norwegian Institute of Land Inventory (NIJOS) demonstrates that photogrammetry is an effective method for collecting data for geographical information systems (GIS). The process of establishing a photogrammetric data capture system is explained with special attention devoted to financial and personnel considerations. It is argued that photogrammetric data capture is viable provided that a stereodigitiser is used in conjunction with a modular solution GIS.     

IMPROVING INTERIOR ORIENTATION FOR ASMALL STANDARD CAMERA

Interior orientation (the initial step in comparator-based photogrammetry) requires a set of known photo co-ordinates to act as reference points. Fiducials serve this purpose on large format, metric cameras, as do réseau targets on small format, semi-metric cameras. Most small format cameras, however, have neither fiducials nor a réseau plate. The aim of this study was to establish fiducials in a small standard camera (Pentax 645) so that its imagery could be used for photogrammetric computations. This paper describes two methods of establishing fiducials, followed by a comparison of their stability and suitability for photogrammetric purposes.     

The pulsation of Delta-Scuti stars

Evolution, linear pulsation, and nonlinear pulsation codes were combined to produce nonlinear models of Delta-Scuti stars in an instability region extending over 3.8T _e<3.95 and 0.6L/L <2.0. The linear analysis upheld the consensus that they are normal Population I stars of about 2M , in stages of evolution corresponding to central hydrogen burning and shell hydrogen burning. The growth rates were very slow; driving was due to an opacity mechanism in the second helium ionization region; periods and period ratios of the lowest modes of the models were in the same range as those observed. A wide range of nonlinear models was investigated. When eigenfunctions from the linear analysis were used as initial velocity profiles, it was found that the dominant peak in the periodogram of the light curve corresponded to the mode initiated. For a small subset of models, limiting amplitudes were identified, and were found to be in close agreement with observed light amplitudes.