Distance Inland Research Articles

Monsoonal influences on evapotranspiration of savanna vegetation of northern Australia.

Data from savannas of northern Australia are presented for net radiation, latent and sensible heat, ecosystem surface conductance (G s) and stand water use for sites covering a latitudinal range of 5° or 700km. Measurements were made at three locations of increasing distance from the northern coastline and represent high- (1,750mm), medium- (890mm) and low- (520mm) rainfall sites. This rainfall gradient arises from the weakened monsoonal influence with distance inland. Data were coupled to seasonal estimates of leaf area index (LAI) for the tree and understorey strata. All parameters were measured at the seasonal extremes of late wet and dry seasons. During the wet season, daily rates of evapotranspiration were 3.1-3.6mm day-1 and were similar for all sites along the rainfall gradient and did not reflect site differences in annual rainfall. During the dry season, site differences were very apparent with evapotranspiration 2-18 times lower than wet season rates, the seasonal differences increasing with distance from coast and reduced annual rainfall. Due to low overstorey LAI, more than 80% of water vapour flux was attributed to the understorey. Seasonal differences in evapotranspiration were mostly due to reductions in understorey leaf area during the dry season. Water use of individual trees did not differ between the wet and dry seasons at any of the sites and stand water use was a simple function of tree density. G s declined markedly during the dry season at all sites, and we conclude that the savanna water (and carbon) balance is largely determined by G s and its response to atmospheric and soil water content and by seasonal adjustments to canopy leaf area.

Status, distribution and conservation of crocodiles in Sri Lanka

Two species of crocodile occur in Sri Lanka, namely the marsh crocodile ( Crocodylus palustris) and the estuarine crocodile ( Crocodylus porosus), confined largely to the low-country in the first peneplain. Both species have declined in range and number since the turn of the century, mainly through over-hunting for hide and meat in the past, and conversion of their habitat to other land-uses by man at present. They have been completely extirpated from the Jaffna peninsula in the north. The study on the status and distribution of crocodiles was carried out from 1991 to 1996 during which crocodiles were recorded from 113 localities, 105 of which were inhabited by the marsh crocodile ( C. palustris), while 33 localities harboured the estuarine crocodile ( C. porosus). The two species were sympatric in 25 localities. Of the 105 localities from which C. palustris were recorded, it was considered rare in 62, common in 35, abundant in five, and perhaps extinct recently in three. Of the 41 large river systems, 32 were found to support crocodiles. Both species of crocodile are particularly abundant and secure in the country's two premier conservation areas: the Ruhuna National Park in the south-east and the Wilpattu National Park in the north-west. It is estimated that there could be at least 1220 marsh crocodiles, and perhaps no more than 300 estuarine crocodiles in Sri Lanka. Crocodiles are being threatened by indiscriminate destruction of the island's mangroves and marsh vegetation for human habitation and prawn farming. In Sri Lanka, the marsh crocodile is known to tolerate concentrations of salt higher than that in sea water for a long time. The estuarine crocodile is known to move a considerable distance in land from the coast. The strong territorial behaviour among the male estuarine crocodiles may perhaps help space the individuals. Crocodiles have a poor image in Sri Lanka. Most rural people consider them a serious and potentially dangerous pest and so do not regret their disappearance from their neighbourhood. Marsh crocodiles can be ranched, but the concept of sustainable utilization of wildlife in general is still anathema to a large segment of the population in Sri Lanka. On the other hand, if crocodiles could benefit people, they are not likely to become extinct.

NESTING DENSITY AND REPRODUCTIVE SUCCESS IN A COLONIAL SEABIRD, THE MAGELLANIC PENGUIN

A central tenet of density-dependent habitat selection theory, that individual fitness generally declines with increasing population density, has led to the hypothesis that, for colonial species, living at high density produces advantages that outweigh the costs. Seabirds have provided evidence for this hypothesis, and positive effects of high density have been offered as explanations for coloniality in this overwhelmingly colonial group. We investigated effects of nesting density on reproductive success of a colonial seabird that nests at variable densities, the Magellanic Penguin (Spheniscus magellanicus). Using breeding success data collected from 1984 to 1991 as part of a long-term study of this species at a large colony at Punta Tombo, Argentina, and experiments that included manipulation of nesting density, we addressed effects of nesting density at two spatial scales: the within-colony area scale (hundreds to thousands of square meters) and the very small scale of a penguin's immediate surroundings (distance to nearest neighbor). Nest density at the colony averaged 8.7 active nests/100 m2 and ranged from <1 to >50 active nests/100 m2 (n = 873 plots). In 100-m2 plots sampled from 1987 to 1990 over large areas of the colony of similar average nest quality and distance inland, the number of fledglings per active nest was inversely correlated with nest density. Experienced breeders using high-quality nests in a high-density study area (>20 nests/100 m2) had 0.25 fewer fledglings per active nest than similar birds nesting in a low-density area (<6 nests/100 m2). Penguin fights (during which eggs and chicks may be lost), nonbreeding “prospectors” (who can start fights and kill chicks), and nest predation were all significantly more prevalent in the high-density area. Within a low-density area, birds nesting within touching distance of neighbors (≤80 cm) had significantly lower success than those with more distant neighbors. Nests where fighting occurred were significantly closer to their neighbors than were nests where no evidence of fighting was observed. We found no association between predation and distance to nearest neighbor. Experimental data were consistent with correlative results. In a plot with reduced density, fledging success was higher (P < 0.10) and fewer agonistic behaviors and predators were observed than in higher density plots. Chicken eggs placed in vacant nests remained untouched by predators longer in low-density areas of the colony than in high-density areas. All results indicated that yearly fledging success declines with increasing density at both the local and area scale, and that rates of predation and intraspecific aggression increase with density. The consistently negative effect of increased density begs the question of why Magellanic Penguins are colonial. Possible explanations include benefits to lifetime reproductive success not reflected in yearly fledging success (e.g., mate and nest acquisition or retention) and benefits of aggregation at spatial scales larger than those investigated in this study.

Paul in Pamphylia (Acts 13.13–14a; 14.24b–26): A Critical Note

Acts states in 13.13–14a that Paul sailed on his outward journey from Paphos in Cyprus to Pergê in Pamphylia (Περγη), proceeding then to Pisidian Antioch – literally, Antioch-towards-Pisidia. (Pamphylia is the westernmost of two alluvial coastal shelves on the south coast of present-day Turkey; a relatively self-contained geographical area.) Acts states that John-Mark left for Jerusalem from this point after a disagreement, and also does not mention the coastal port of Attaleia (‘Ατταλεια), present-day Antalya. On the return journey, however, noted in 14.24–26a, the remaining missionaries are said to preach in Pergê and then proceed to Attaleia, from which point they sail on to Syrian Antioch, presumably actually disembarking at Seleucia. Now this all looks a little odd at first glance, especially since Pergê is some distance inland for any arrival on the first leg of this journey, and most interpreters have reacted accordingly. I want to suggest here, however, that the author's comments about these two traverses through Pamphylia, although brief and initially a little puzzling, are deliberately asymmetrical, and it is this that betrays their almost certain accuracy in historical terms.

Space and time variation of δ18O andδD in precipitation: Can paleotemperature be estimated from ice cores?

A one‐dimensional model of meridional water vapor transport is used to evaluate the factors that control the spatial and temporal variations of oxygen (δ18O) and hydrogen (δD) isotopic ratios in global precipitation. The model extends Rayleigh descriptions of isotopes in precipitation by including (1) effects of recharge to air masses by evaporation and (2) horizontal transport by both eddy fluxes and advection. Globally, spatial variations in precipitation δ18O and δD depend on the ratio of evaporation to the product of horizontal moisture flux and horizontal temperature gradient. At low latitudes, where this ratio is large, precipitation δ18O and δD are closely tied to the isotopic ratios of oceanic evaporation. At high latitudes the ratio is small, and δ18O and δD are controlled by the ratio of advective transport to eddy transport. Transport by eddy fluxes induces less fractionation than transport by advection, resulting in a smaller gradient of isotopic ratios with temperature. The model‐predicted temporal relationships between δ18O (or δD) of Antarctic precipitation and temperature do not necessarily coincide with the modern spatial relationship and depend strongly on the proximity of the precipitation site to the ocean evaporation source. Sensitivity of δ18O to temporal changes in local surface temperature is low at coastal sites and increases with distance inland. These results suggest a possible explanation of the apparent discrepancy between borehole temperature inversion estimates of glacial temperatures and temperatures inferred from the modern spatial δ18O—surface temperature relationship.

Environmental Indicators of Habitat Quality in a Migratory Freshwater Fish Fauna.

/ In general, diadromous (and particularly amphidromous and catadromous) freshwater fishes decline in frequency of occurrence, change age/size structure, and probably also decline in abundance with increasing elevation and distance upstream from the sea. In freshwater fish faunas with a high proportion of migratory species, as in New Zealand, these changes in occurrence and abundance result in a breakdown of the relationship between fish abundance and habitat quality, making application of the index of biotic integrity (IBI) as a measure of habitat quality problematical since the index depends on the relationship between population metrics and habitat quality. An alternative approach applicable to assessing temporal changes in habitat quality and that uses a large database on fish distributions, involves analysis of the distribution of species across their natural distributions. In this paper we generate curves of occurrence of species across ranges of altitude and distance inland and show, through comparisons of data subsets, that the curves are consistent estimators of species' occurrence and therefore useful as indicators of habitat quality.

Spatial variability of Antarctic surface snow glaciochemistry: implications for palaeoatmospheric circulation reconstructions

Ice core glaciochemical records provide detailed information on past changes in atmospheric chemical composition and circulation, which is essential for understanding the timing and phasing of climatic change in different regions. Atmospheric circulation reconstructions based on these records require knowledge of modern chemical concentration controls (chemical source, transport pathway and strength) and spatial variability. To gain insight into these processes, glaciochemical data collected during reconnaissance drilling in West Antarctica combined with all other existing Antarctic surface snow glaciochemical records are examined for trends in chemical concentration vs distance inland, elevation, and accumulation rate. Snowpit data from inland West Antarctica displays significant spatial variability, suggesting complex patterns of atmospheric circulation and moisture transport in the region. Siple Dome sea-salt and methanesulphonic acid (MSA) concentrations are similar to coastal sites, suggesting enhanced advection of marine air masses to the site. Statistical analysis of a 110-year high-resolution Siple Dome ice core record confirms that strong lower tropospheric circulation dominates the region, which is most likely related to the strength of the Amundsen Sea low pressure system. An atmospheric circulation reconstruction based on the ice core glaciochemical data displays significant interannual and decadal-scale variability, but there is no overall trend in atmospheric circulation strength at Siple Dome in the past 110 years.

Spatial variations of wet deposition rates in an extended region of complex topography deduced from measurements of 210Pb soil inventories

The radionuclide 210Pb derived from gaseous 222Rn present in the atmosphere becomes attached to the same aerosols as the bulk of the main pollutants sulphur and nitrogen. When scavenged from the atmosphere by precipitation, the 210Pb is readily attached to organic matter in the surface horizons of the soil. Inventories of 210Pb in soil can thus be used to measure the spatial variations in wet (or cloud) deposition due to orography averaged over many precipitation events (half-life of 210Pb is 22·3 year). Measurements of soil 210Pb inventories were made along a transect through complex terrain in the Scottish Highlands to quantify the orographic enhancement of wet deposition near the summits of the three mountains Ben Cruachan, Beinn Dorain and Ben Lawers, which, respectively, lie at distances of approximately 30, 55 and 80 km from the coast in the direction of the prevailing wind. The inventory of 210Pb on the wind-facing slopes of Ben Cruachan shows an increase with altitude that rises faster than the precipitation rate, which is indicative of seeder-feeder scavenging of orographic cloud occurring around the summit. Results for Beinn Dorain show a smaller rise with altitude whereas those for Ben Lawers give no indication of a rise. It is concluded that the seeder–feeder mechanism in regions of complex topology decreases in effectiveness as a function of distance inland along the direction of the prevailing wind.

Regional isotope effects and application to hydrologic investigations in southwestern California

Stable isotopic compositions of locally derived and imported surface and groundwaters in southwestern California provide a quantitative background for assessment of a variety of hydrologie and meteorologie questions. Geographically controlled meteoric water isotope‐ratio variations in the maritime climate zone of southwestern California show best fit δD dependence on latitude (−2.0‰ per degree), distance inland (−21‰ per 100 km), and elevation (−10‰ per kilometer). Meteoric and evaporative fractionations provide distinctive isotopic signatures that permit tracing of transported waters, as well as identification of watersheds for those precipitated locally. This regional framework of evaporative and meteoric isotope fractionation trends permits interpretation of local recharge and subsurface hydrology in the San Jacinto region. Similar techniques may be applied to other regions in southwestern California where differing source watersheds, surface or subsurface transport, and mixing provide significant variations in groundwater isotopic composition.

MOSQUE ARCHITECTURE IN BUGANDA, UGANDA

Writing this short paper was prompted, first, by the alarming pace at which the destruction of earlier mosques is proceeding in Buganda, as they are replaced by new mosques built out of concrete in what is best termed the Oriental style; and, second, by the general absence of published material on the Islamic religious architecture of Uganda or, indeed, of East-Central Africa as a whole.' The kingdom of Buganda lies within the present-day Republic of Uganda.2 Encompassing Kampala, the capital of Uganda, it stretches along the northern shore of Lake Victoria for 200 miles, and for some distance inland (fig. 1). Buganda3 was possibly the

Controls on dune colour in the Namib sand sea: preliminary results

The red colouration observed in many sand seas is a consequence of fine grained haematite and clay coatings surrounding quartz grains and a number of hypotheses have been proposed to account for this. The marked increase in dune redness with increasing distance inland in the northern area of the Namib sand sea is investigated using satellite imagery and mineral magnetic measurements. These results suggest that source materials exert at least a partial control on dune colour in this field setting, but that evidence for the influence of other factors (e.g. climatic gradient and/or abrasion of coating during transport) is also present.

Rainfall variability and agriculture in the semi-arid tropics—the Northern Territory, Australia

Recent interest in climatic change raises particular questions of scale and impact on cropping in the monsoonal regional of the Northern Territory, Australia. This paper opens by considering these three issues briefly. In this context it then follows with analyses of historical rainfall records for four sites, three of particular interest for local agriculture and the fourth of more meteorological interest in a wider, global context, for up to 103 seasons, 1888–1889 to 1990–1991. Differences in seasonal rainfall and raindays are identified over this period. But, the higher variabilities that occur for relevant fortnightly periods within seasons prevent the identification of any trends or differences for these shorter time spans. The most recent seasons, those within living memory since the mid 1960s, have generally been wetter than earlier seasons. Selection of seven core fortnights within seasons allows calculation of simple and binomial probabilities of key threshold amounts of rainfall for cropping. Generally, these probabilities decline with increased distance inland, with increases in the threshold and vary amongst the fortnightly periods. Local fieldwork suggests two criteria for sowing and another rainfall criterion for damage to crops at harvest. Analyses of their occurrences emphasise the variability within seasons, although differences could not be detected between periods of record. The analyses also show the relative scarcity of these sowing rainfall criteria during key periods within seasons. Conversely, rainfall events that could have an adverse impact on crop quality at harvest time occur at all sites in the majority of seasons. Thus, regardless of further climatic change the records provide evidence of considerable variability in rainfall and hence in conditions for agriculture in the region. Producers need to respond quickly to the occurrence of appropriate conditions and these analyses underline difficulties in doing this.

Study of airborne radioactivity near to the high water mark at Drigg Point

Measurements are reported on radionuclides collected at Drigg Point using muslin screen aerosol collectors arranged along two transects leading inland from the high water mark for ~300m. The results of seven long-term exposures, taken over periods of 1.0–8.2 weeks, and three short-term exposures, taken over 1.5–2.2 h at different states of the tide, are presented. A determination of γ-ray emitting radionuclides collected by the screens was used to determine the relative concentrations of radioisotopes in the air as a function of distance inland. Average wind speeds were calculated for each exposure using data obtained from the nearby Eskmeals weather station. Reductions in the radionuclide concentrations vs distance inland calculated using the SALT model of Nelis et al. ( Atmos. Environ. 1994, 28, 3213–23) are shown to reproduce the data reasonably well. It is concluded that the results are useful for testing models of the radionuclide dispersion and deposition.

Geology of the Ahuas Area in the Mosquitia Basin of Honduras: Preliminary Report

Following a 36-fold seismic survey that covered 460 km, two exploratory wells were drilled between July 1991 and August 1993 in the Ahuas area, on the Patuca tectonic belt, in the Mosquitia savannah in northeastern Honduras. The Embarcadero 1 well encountered only dense, barren, gray and red siliciclastics and some phyllite at total depth. The Raiti-Tara 1 well also drilled mostly barren, but less dense, red beds that included some Upper Cretaceous limestone conglomerate in the lower section. We did not find source or reservoir rocks in either well, nor did we find hydrocarbon shows. The absence of Lower Cretaceous limestone in both wells is significant because more than 1500 m of limestone are exposed 35-50 km southwest in the Colon Mountains. The lithology of the clastics in the Embarcadero well is similar to Middle and Upper Jurassic formations in central Honduras. The lithology of the softer red beds in the Raiti-Tara well suggests they are Tertiary fill in a pull-apart basin. The Mosquitia basin, including the Ahuas area, probably was on the seaward side of the Chortis block (once part of Mexico) and received only Jurassic sediments until it was elevated by arc magmatism in the Early Cretaceous. However, thick Lower Cretaceous platform carbonates were deposited some distance inland. Lateral forces in the early Late Cretaceous caused the outer edge of Chortis to break up, carrying the Colon carbonate block up to 50 km northwest by sinistral fault movement. Later, antithetic dextral displacement offset the various blocks and created pull-apart basins that filled with Tertiary sediments. In the early Paleocene, compression from a spreading center to the southeast ruptured the Jurassic rocks, creating a decollement and later thrusting. No complete petroleum system seems to exist along the axis of the uplifted Patuca tectonic belt largely because of the lack of organic-rich source rocks and the presence of complicated young structures.

Tidal Water Level Fluctuations in Water Wells on San Salvador Island, Bahamas

Water level fluctuations were measured in fifteen water wells near the Cockburn Town airport, in Grahams Harbor lagoon and in Riding Rock marina using custom-built electrical-capacitance tide gages. Results indicate prominent tidal cycles in all wells with tidal ranges between approximately 20 cm and 110 cm. Observed well tides show a similar mixed tidal pattern as predicted ocean tides with tidal lag times ranging from near 0 to 60 min and semidiurnal tide attenuation of 5 percent to 80 percent. Measured marine tides in the Riding Rock marina occur at the predicted times but are higher than predicted. Marine tides recorded in Graham9s Harbor correlate poorly with tide table predictions, have about half the predicted range and occur approximately one hour later than predicted. Lag times and tidal attenuations in wells show no clear correlation with distance from the coast and are largely incompatible with the tidal attenuation model of Ferris (1951). Well water salinities are inversely correlated with relative tidal ranges. Diurnal tide components in most wells are enhanced with respect to predicted ocean tides. Aquifer transmissivities calculated from observed semidiurnal tidal lag times, tidal range attenuations, and inland distances are surprisingly high and indicate great aquifer thickness. These results may be largely attributable to a highly cavernous, inhomogeneous subsurface to a depth of several kilometers, major tidal conduits near several wells, irregular coastlines, atmospheric pressure fluctuations, evapotranspiration cycles and unmodeled precipitation events.

Chaotic deposition by a giant wave, Molokai, Hawaii

Research Article| July 01, 1994 Chaotic deposition by a giant wave, Molokai, Hawaii JAMES G. MOORE; JAMES G. MOORE 1U.S. Geological Survey, Menlo Park, California 94025 Search for other works by this author on: GSW Google Scholar WILFRED B. BRYAN; WILFRED B. BRYAN 2Woods Hole Oceanographic Institution, Woods Hole, Massachusetts 02543 Search for other works by this author on: GSW Google Scholar KENNETH R. LUDWIG KENNETH R. LUDWIG 3U.S. Geological Survey, Denver, Colorado 80225 Search for other works by this author on: GSW Google Scholar GSA Bulletin (1994) 106 (7): 962–967. https://doi.org/10.1130/0016-7606(1994)106<0962:CDBAGW>2.3.CO;2 Article history first online: 01 Jun 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation JAMES G. MOORE, WILFRED B. BRYAN, KENNETH R. LUDWIG; Chaotic deposition by a giant wave, Molokai, Hawaii. GSA Bulletin 1994;; 106 (7): 962–967. doi: https://doi.org/10.1130/0016-7606(1994)106<0962:CDBAGW>2.3.CO;2 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGSA Bulletin Search Advanced Search Abstract A coral-basalt breccia-conglomerate is exposed >60 m above present sea level and nearly 2 km inland from the present shoreline on the southwest side of East Molokai Volcano, Molokai. The conglomerate is preserved mantling interfluves between gullies and forms a blanket- like deposit 0.5 to 3 m thick. No evidence of a wavecut terrace either within the blanket or at its upper or lower limits of exposure can be found. No coral was found in growth position. Unsorted basalt clasts as large as boulder size are subrounded to angular, randomly oriented, and vary from 2-3 to >50 volume% of the deposit. The size of the largest basalt and coral fragments shows almost no systematic variation with elevation, distance inland, or lateral position parallel to the shore.Two indistinct rock units are present in a few places, a lower carbonate-rich unit that we interpret as an "onwash facies" and an upper basalt-rich unit, an "offwash facies.". The carbonate-rich onwash facies is dominated by biogenic debris, especially fragments of coral and beach rock and gastropod and bivalve shells. The offwash facies contains 40% to >90% basalt cobbles and boulders in a matrix of finely broken biogenic fragments. Where the distinct facies are lacking, the proportion of basalt clasts increases crudely from the lower to the upper part of the conglomerate at a single place and from lower to higher elevation out-crops. Where the deposit overlies a cinder cone, several carbonate-bearing elastic dikes extend from the conglomerate as much as 10 m down into the basalt cinders.This deposit was apparently laid down by a giant wave that broke over an outer reef, similar to the present fringing reef, and advanced as a turbulent bore over the back-reef flat, picking up a slurry of carbonate-rich debris and depositing it on the slopes inland as the wave advanced. The offwash picked up loose basalt debris on its return flow. U-series dating of coral fragments indicates that the age of this deposit is 240-200 ka, indicating the wave is distinct from that which produced a similar deposit on Lanai about 100 ka. This giant wave was most likely caused by one of the many large submarine landslides that have been identified on the lower slopes of the major Hawaiian Islands. This content is PDF only. Please click on the PDF icon to access. First Page Preview Close Modal You do not have access to this content, please speak to your institutional administrator if you feel you should have access.

Ammonium sorption to channel and riparian sediments: A transient storage pool for dissolved inorganic nitrogen

Sediment (0.5 mm–2.0 mm grain size) was incubated in nylon bags (200 μm mesh) below the water table in the channel and in two transects of shallow wells perpendicular to the banks (to 18 m) of a third-order stream during August, 1987. One transect of wells drained steep old-growth forest, and the other a steep 23 year-old clear-cut partially regenerated in alder. At approximately 6-week intervals between October, 1987, and June, 1988, bags were retrieved. Total exchangeable ammonium was determined on sediment, and dissolved oxygen, nitrate and ammonium were determined in stream and well water. Exchangeable ammonium ranged from 10 μeq/100 g of sediment in the stream where nitrification potential and subsurface exchange with stream water were high, to 115 μeq/100 g sediment 18 m inland where channel water-groundwater mixing and nitrification potential were both low. Sorbed ammonium was highest during summer/autumn base flow and lowest during winter storm flow. Both channel and well water contained measurable dissolved oxygen at all times. Ammonium concentration was typically < 10 μg-N/L in channel water, increased with distance inland, but did not exceed 365 μg-N/L at any site. Nitrate concentration was typically higher in well water than channel water. Nitrate levels increased dramatically in wells at the base of the clear-cut following the onset of autumn rains. The results indicate a potential for temporary storage of ammonium on riparian sediments which may influence biotic nitrogen cycling, and alter the timing and form of dissolved inorganic nitrogen transport from the watershed.

A Two-Dimensional Simulation of the Iberian Summer Thermal Low

Abstract The forcing mechanisms of the diurnal thermal depression formed over the Iberian Peninsula in the summer and the typical air circulation induced over the Northern Plateau are analyzed by a two-dimensional hydrostatic, high-resolution, primitive equation model applied in a vertical plane perpendicular to the coastline of the Bay of Biscay. Such circulation is characterized by a low-level flow of relatively cold air that progresses inward over the elevated central plateau throughout the afternoon and evening, reaching inland distances up to 150 km at dawn, which tends to fill up the already formed thermal depression. Despite the simplicity of the model, the results obtained show a satisfactory agreement with observations. Finally, a comparison is made between results obtained from a set of simulations with different combinations of land-use types, topographic profiles, thermal stability, and synoptic wind, keeping the other conditions fixed, in order to analyze the individual effects of different t...

Effects of salt spray and sand burial on Spinifex sericeus R. Br.

Abstract Spinifex sericeus, a common coastal sand dune grass, typically exhibits decreased vigour in the more stabilized section of the dunes when compared with the active foredune. These differences in vigour appear to be related to different environmental conditions across the dunes such as sand burial and salt spray deposition, both generally decreasing with distance inland. An experiment following the fate of foliar and root applications of 22Na indicated that it may be taken up by the roots or the foliage and then translocated throughout the whole plant, and perhaps even extruded by the roots. Salt spray appeared to have a positive effect on the growth of S. sericeus when applied in conjunction with N and P but had no effect when N and P were not added. Adding acid‐washed or non acid‐washed foredune sand also resulted in a positive growth response. The results of these experiments indicate that the vigorous growth of S. sericeus on the dynamic sections of the foredunes is due to a stimulation of growth caused by sand deposition.

Geology of the Akitio area (1:50 000 metric sheet U25BD, east), northeastern Wairarapa, New Zealand

The Akitio area, located entirely within the east coast ranges, north Wairarapa, is largely composed of Cretaceous strata which overlie the westward‐subducting Pacific plate. The oldest strata, Pahaoa Group, composed of indurated sandstone and mudstone of Early Cretaceous (Albian) age, are in the central part of the mapped area within the fault‐bounded Owahanga Block. The Springhill Formation, which follows, is restricted to one small outcrop adjacent to a north‐trending fault.Younger Cretaceous (mid and Late Cretaceous) and Paleocene strata are mapped as Mangapurupuru Group (Kipihana and Te Mai Formations) and Tinui Group (Whangai and Waipawa Formations). These strata crop out largely in the southern and eastern parts of the sheet district. However, the Whangai Formation is also mapped within, and to the west of, the Tinui Fault Complex.The early Cenozoic Wanstead Formation is present locally in the eastern part of the area mapped, and in two diapirs which lie a short distance inland, and also within the Tinui Fault Complex. The highly calcareous Weber Formation is within, and to the west of, the Tinui Fault Complex, but is absent east of the complex. The early Miocene Whakataki Formation, largely composed of Bouma sequences, is present along a northeast‐trending narrow belt parallel to the shore, and as rafts within the Mt Cadmus Diapir, and in a small area west of the diapir. Strata of early‐mid Miocene age crop out west of the Tinui Fault Complex, but marine strata younger than middle Miocene are absent from the sheet district.The most important structural element of the Akitio area is the Tinui Fault Complex in the west. The Tinui Fault, and those faults further to the west, is usually almost vertical, whereas faults to the east of the fault commonly dip c. 73° to the west. Two, low‐angle westward‐dipping thrusts are mapped near Akitio Station. Diapirs, caused partly by intense compression of the incompetent bentonitic Wanstead Formation, are mapped near the coast and within the Tinui Fault Complex near Mt Cadmus.