Malta: macropolitical threats

Despite constitutional neutrality and non-alignment, for the last decade Malta has dabbled in Western security circles. By pledging commitment to the European CFSP and forging closer associations with NATO the government consummated allegiances with the hegemonic flank of their region and the only remaining superpower. However, Maltese security in the post-Cold War era is about more than just power fealty. Whilst not overlooking the still highly relevant military threats to security, this paper elucidates three macropolitical threats that are too impetuous for the worlds most powerful security organizations to handle. Indeed, future Maltese membership of the WEU or closer ties with NATO may even exacerbate these menaces.     

Isolation of integrals for centroid orbits in stellar system models

In this paper we present two solutions for isolating integrals of the centroid motion in a non-stationary stellar system under the ellipsoidal hypothesis with point-axial symmetry.Paper presented at the 11th European Regional Astronomical Meetings of the IAU on New Windows to the Universe, held 3–8 July, 1989, Tenerife, Canary Islands, Spain.     

On the yearly phase delay of winter intraseasonal mode in the western United States

In the western United States, persistent and recurrent flow patterns not only modulate precipitation events but also result in prolonged surface inversion episodes. In this region, the frequency of persistent ridge/trough events ranges between 20 and 40 days, well within the intraseasonal timescale. Based on NCEP reanalysis data starting at 1949, with a focus on the interior West, we observed that episodes of prolonged ridge/trough events appear to occur about a week later every year and resets every 5–7 years—a previously undocumented phenomenon examined herein. Diagnostic analyses indicate that the interplay between regional intraseasonal flow patterns and the North Atlantic Oscillation (NAO) alternates the preferred timeframe for the persistent ridge/trough events to occur. This may result from different phases of the NAO shifting the winter mean ridge and such shifts modulate the occurrence and timing of persistent ridge/trough events. When the timing changes evolve around the quasi-6 years cycle of the NAO, the resultant evolution forms what appears to be a steady phase delay in the ridge/trough events year after year. These results are a further step in disclosing the multiple-scale interaction between intraseasonal and interannual modes and its regional climate/weather impact.     

Ozone during stratospheric warmings at Uccle

The day-to-day variations in ozone content at Uccle (51oN) during some stratospheric warming events are ex-amined. In particular, the attention is focused on the timing of commencement of ozone enhancement prior to peak day of warming and on the relationship in the ozone content between the upper and lower stratosphere. These two features are compared with the predictions of ozone transport models. There seems to be an agreement between mod-el predictions and observed features in some cases.     

A 35,000 Year Vegetation and Climate History from Potato Lake, Mogollon Rim, Arizona

A new record from Potato Lake, central Arizona, details vegetation and climate changes since the mid-Wisconsin for the southern Colorado Plateau. Recovery of a longer record, discrimination of pine pollen to species groups, and identification of macrofossil remains extend Whiteside's (1965) original study. During the mid-Wisconsin (ca. 35,000-21,000 yr B.P.) a mixed forest of Engelmann spruce (Picea engelmannii) and other conifers grew at the site, suggesting a minimum elevational vegetation depression of ca. 460 m. Summer temperatures were as much as 5°C cooler than today. During the late Wisconsin (ca. 21,000-10,400 yr B.P.), even-cooler temperatures (7°C colder than today; ca. 800 m depression) allowed Engelmann spruce alone to predominate. Warming by ca. 10,400 yr B.P. led to the establishment of the modern ponderosa pine (Pinus ponderosa) forest. Thus, the mid-Wisconsin was not warm enough to support ponderosa pine forests in regions where the species predominates today. Climatic estimates presented here are consistent with other lines of evidence suggesting a cool and/or wet mid-Wisconsin, and a cold and/or wet late-Wisconsin climate for much of the Southwest. Potato Lake was almost completely dry during the mid-Holocene, but lake levels increased to near modern conditions by ca. 3000 yr B.P.     

The Application of Telemetry to Large-Scale Horizontal Anisotropic Permeability Determinations by Surface Tiltmeter Survey

An advanced two-way radio link (transceiver units) and data logging system have provided a powerful means of real-time series data collection and analysis. The application of this telemetry system to surface tiltmeter surveys provides significant cost savings for testing and analysis of deep, large-scale horizontal anisotropic permeability and heterogeneity determinations.
The determination of horizontal anisotropic properties requires one pumping well and eight to 10 tiltmeter monitoring stations. The validity of the depth of the test may reach 4,000 feet below land surface. With the addition of one partially penetrating observation well, the entire three-dimensional anisotropic permeability can be determined. With the addition of a fully penetrating well, the storage coefficient can be determined as well as leakage property (including vertical permeability of the confining layers). An example test case was analyzed for horizontal anisotropic permeability with remarkable success despite relatively unfavorable detection conditions.
A thorough understanding of the geology overlying the aquifer system must be made in order to assess the applicability of the surface tiltmeter survey to large-scale horizontal anisotropic permeability determinations.     

Field observations of stratified atmospheric flow above an obstacle

In a study using the plume from the Four Corners power plant, near Farmington, N.M., lee waves were observed during times when the plume flowed across the Hogback. Wavelengths were typically about 1.2 km; wave amplitudes were more variable, ranging from 20 to 100 m. The observed amplitudes imply an obstacle that is broader and shallower than is actually the case. This is in agreement with laboratory studies that show the existence of regions of complex flow both upstream and downstream from an obstacle, which have the effect of broadening the region over which laminar flow occurs. Visual observation, measurement of the plume cross-sectional area both upstream and downstream from the Hogback, and measurement of plume aerosol concentrations show that turbulent and eddy flow over and downwind from the Hogback increase the rate of mixing of the plume with the surrounding atmosphere. This in turn increases the rate at which plume components come into contact with the ground.     

Health and nutrition in the Pacific islands: Development or underdevelopment?

Although modernization has undoubtedly brought about significant improvements in and access to modern health services and has lowered the previously high incidence of some infectious diseases and perinatal deaths, there is increasingly widespread evidence that some old and some new, often very serious health and nutritional problems still exist in all parts of the often “Edenized” Pacific islands. Although “development” has occurred, both infectious and non-communicable degenerative diseases, perinatal mortality, and nuclear pollution still constitute major health problems, and food systems, nutritional status, and nutrition-linked health seem to have deteriorated.     

Permian

Summary Late in the Carboniferous Period or early in the Permian ice covered much of Tasmania (Fig. 30b). The sub‐Permian surface had a relief of several thousand feet with particularly low areas near Wynyard and Point Hibbs and high areas near Cradle Mountain, Devonport, Deloraine, Wylds Crag and Ida Bay and a peninsula in eastern Tasmania (Fig. 30a).

The glaciers from an ice centre north‐west of Zeehan diverged about a higher area near Cradle Mountain. One tongue occupied a deep valley near Wynyard and a lobe fanned out south of the high area to occupy parts of northern and central Tasmania and to override some parts of the east coast peninsula.

West of Maydena the ice scoured shell beds and dumped the shell fragments in the till on the Styx Range. Thus the base of the ice may well have been below sea‐level. Carey and Ahmad (1961) suggested that the Wynyard Tillite was deposited below a “wet‐base” glacier. David (1908, p. 278) suggested deposition from “land ice in the form of a piedmont or of an ice‐sheet” but that near Wynyard the ice came down very close to, if not actually to, sea‐level. The extent of the glaciation and the distribution of erratics of western Tasmanian origin in eastern Tasmania make it seem likely that either a piedmont glacier or an ice‐sheet rather than mountain glaciation was involved.

Following retreat of the glaciers the sea covered the till, probably to a considerable depth, eustatic rise of sea‐level being much more rapid than isostatic readjustment.

The Quamby Group is underlain by or passes laterally into thin conglomerates and sandstones in a number of places, but most of the group appears to be of deep water, partially barred basin origin. Marine oil shales accumulated close to islands. Shallowing of the sea during deposition of the upper part of the Quamby Group seems to be indicated by the fauna and increasing sandiness in marginal areas. Instability in the source areas is shown by the presence of turbidity current deposits in the higher parts of the group. The Golden Valley Group, of Upper Sakmarian and perhaps Lower Artinskian age, was deposited in a shallower sea than the Quamby Group but the deposits are more extensive along the east coast peninsula and on the flanks of the Cradle Mountain island. This anomaly may be explained if the rate of deposition exceeded the rate of rise of sea‐level. The sediments of the Golden Valley Group became finer‐grained upwards in most parts of Tasmania probably indicating reduction in relief of the source area. Some instability is indicated by turbidity current deposits. Uplift of source areas in north‐western Tasmania early in Artinskian time resulted in the spreading of sand over the shallow silts of the Golden Valley Group onto the east coast peninsula and over the Cradle Mountain area. The sand formed a wide coastal plain containing lakes and swamps and the sea was restricted to a small gulf in southern Tasmania during the deposition of the lower part of the Mersey Group. During deposition of this group the sea rose once to form a long, narrow gulf extending as far north as Port Sorell and then retreated. This inundation resulted in the development of two cyclothems in many parts of Tasmania.

A little later in Lower Artinskian time the sea rose and covered most of Tasmania except perhaps the far north‐west. This wide transgression probably resulted from down‐warping as an eustatic rise in sea‐level would be expected to produce thickest deposition over the old gulf in southern Tasmania and along the axis of Mersey Group inundation but the zone of thickest Cascades Group crosses these at a high angle. During deposition of the Cascades Group marine life became very abundant in the shallow sea over which a few icebergs floated. During the Artinskian tectonic instability increased as shown by the increasing number of turbidites in the upper part of the Grange Mudstone and the lower part of the Malbina Formation. The sea became less extensive and the source areas in north‐western and north‐eastern Tasmania were uplifted. The zone of thickest deposition of the Malbina Formation trended north‐north‐westerly. The rapid succession of turbidity currents killed the benthonic fauna and it was only during deposition of the upper part of the formation possibly in Lower Kungurian time that life became abundant again in the Hobart area. The sea spread a little over the east coast peninsula and further instability is recorded in the Risdon Sandstone. The resulting turbidity currents killed the benthonic fauna and it never became properly established again in any part of Tasmania during the Permian. A wide shallow sea covered much of Tasmania and was bordered by low source areas during deposition of the Ferntree Group. The axis of greatest thickness had an almost meridional trend and lay west of that of the Malbina Formation. Late in the Permian, probably in the Tartarian, rejuvenation of the source areas, particularly in western Tasmania, and withdrawal of the sea, resulted in deposition of sands and carbonaceous silts of the Cygnet Coal Measures. The zone of greatest thickness was almost parallel to but west of that of the Ferntree Group.

The thickness of the Permian System and the sheet‐like character of many of the members and formations suggest shelf rather than geosynclinal deposition. The average rate of deposition was of the order of 1 ft. in ten thousand years (about 0–003 mm./annum). However, the sediments differ markedly from those on stable shelves in that many of them are poorly‐sorted. Some of the poor sorting may be attributed to deposition from drifting icebergs but some is due to tectonic instability.

Uplift and downwarping and movement of zones of maximum thickness have been deduced above and it is probable that the tectonic instability started as early as Lower Artinskian and it may have started during Sakmarian (upper part of Quamby Group). Maximum instability seems to have occurred in Middle or Upper Artinskian time (Malbina Formation) and it is probably significant that this was a time of considerable orogenic movement in New South Wales (part of the Hunter‐Bowen Orogeny, Osborne, 1950). Progressive westward movement of zones of maximum thickness of units in Upper Permian time seems to have occurred and this again is reminiscent of the situation at the time in New South Wales (Voisey, 1959, p. 201) but seems to have started later. Uplift and development of a major synclinal structure with a trend approximately north‐north‐westerly occurred late in Permian time.