Relative hotspot motions versus True Polar Wander

The fixity of hotspots and mantle plume locations has long been axiomatic. If the assumption of fixed hotspots is granted, ‘absolute’ plate motions and movements of the spin axis with respect to the hotspot framework, defined by some as True Polar Wander (TPW), can be determined. However, this assumption can be tested by paleomagnetic data, and such tests are gradually raising some doubts about the fixity of hotspots. The result is that discrepancies between Cretaceous and Tertiary hotspot and paleomagnetic reference frames are now beginning to be interpreted as the result of plume drift within a convective mantle. In the Indo-Atlantic, hotspots have remained relatively stationary with respect to the spin axis for the last 95 million yr. However, the Pacific hotspots, notably Hawaii, appear to have undergone large-scale southward drift with respect to the spin axis during the Early Tertiary. Global paleomagnetic data do not indicate that any TPW occurred during the Late Cretaceous or Tertiary. Although the Early Cretaceous paleomagnetic and hotspot frames for the Indo-Atlantic realm can be interpreted as slow TPW, direct estimates of paleolatitude and hotspot motion, in particular the Kerguelen hotspot, challenge TPW as a global phenomenon. At present, we consider that the large Early Cretaceous discrepancy between hotspot and paleomagnetic data is best explained by southward drift of the Atlantic hotspots prior to ∼95 Ma.     

Nanoscience and technology: the next revolution in the Earth sciences

Nanoscience and technology are not exactly new, but nevertheless rapidly expanding fields that are providing revolutions in all sciences on the scale of what genomics and proteomics have done in recent years for the biological sciences. Nanoscience is based on the fact that properties of materials change as a function of the physical dimension of that material, and nanotechnology takes advantage of this by applying selected property modifications of this nature to some beneficial endeavor. The prefix ‘nano’ is used because the property dependence on physical size is generally observed close to the nanoscale, somewhere around 10⁻⁹ m. The dimensions at which changes are observed depend on the specific material and the property in question, as well as which of the three dimensions are restricted in real space (e.g. small particles vs. thin films vs. ‘one-dimensional’ phases). Properties change in these confined spaces because the electronic structure (i.e. the distribution of electron energies) of the material is modified here in the gray area between the bulk and atomistic/molecular realms, or equivalently between the continuum and strictly quantum domains. Earth materials with at least one dimension in the nanorange are essentially ubiquitous. Many have been known for several decades and more are being discovered all the time. But the scientific emphasis has now shifted to that of measuring, understanding and ultimately predicting the property changes from the bulk to nanodomains, and to the understanding of the significant ways that Earth processes are affected by these changes. In addition, where possible, Earth scientists are using nanoscience to develop nanotechnology that should play important roles in Earth sustainability issues of the future.     

Mental preparation for climate adaptation: The role of cognition and culture in enhancing adaptive capacity of water management in Kiribati

In many Least Developed Countries (LDCs) and Small Island Developing States (SIDS), such as in Kiribati, formal national adaptation programmes are currently being operationalised or are in the pipeline. A key focus is on motivating householders to adapt in anticipation of climate change through pilot community projects. In this paper, we argue that the water sector must pay equal attention to how communities cognitively perceive the process of adaptation if interventions are to be effective. Adopting a cognitive model to gain such insights we conclude that individual's belief in their own abilities to manage water stress play a crucial role in driving intentions to adapt and therefore greater attention needs to be placed on understanding the underling drivers shaping such beliefs.     

Symposium on the glacial refugia and migration paths of Central and North European trees

A symposium on the glacial refugia and migration paths of Central and North European trees was sponsored by the Løvenholm foundation and held at Løvenholm Castle in Jutland, Denmark, in July 1981. Twenty invited lectures were given by participants from twelve European countries. The symposium showed that it may be possible to identify the migration centres and the origin of local populations of the     

Practical engineering approaches and infrastructure to address the problem of marine debris in Korea

As a solution to the problem of persistent solid marine debris, a nationwide project began in Korea in 1999 to develop and popularize fundamental changes to the infrastructure. The ten year project, called “A Practical Integrated System for Marine Debris,” consists of four linked types of technology: prevention, deep-water survey, removal and treatment (recycling). These reflect the characteristics of marine debris, which though widespread, vary by location and time of generation. Each technical component has each representative outcome that has been outreached the local governments and marine debris-related associations. The in situ infrastructures lead to enhance the retrieval of the marine debris and create direct and indirect benefits to industry. Both end-of-pipe technology improvement and the introduction of front-of-pipe technology should be considered as we strive to reduce the generation of marine debris in Korean coastal areas.     

The strength of Malaysian maritime cluster: The development of maritime policy

A comprehensive maritime industry policy that can be adequately monitored to achieve a competitive advantage is important. The Malaysian maritime industry comprises multifaceted sectors that are governed by fragmented governmental agencies. In this research, we investigated the Malaysian maritime industry cluster comprising three main sectors: Shipping, Ship Industry, Ports and Terminals. The Strength Indicator Model has been developed to reveals the maritime industry cluster. We find that the Competitions, Locations, Connections, Government and Chances factors affect the capability of the Malaysian maritime industry cluster. The result of this study will give a framework for Regulatory bodies and the various stakeholders to support the Malaysia maritime industry progressing toward a more competitive and sustainable development of the industry with the aim to become the developed maritime nation.     

MAPPING AND INTERPRETATION OF FIELD PHENOMENA FOR GROUNDWATER RECONNAISSANCE IN A PRAIRIE ENVIRONMENT,ALBERTA, CANADA

ABSTRACT

Theoretically, a small drainage basin may be divided into equal areas of downward flow and upward flow of groundwater. In regions where surface water does not obscure the phenomena produced by groundwater, these areas can be differentiated by mapping springs, seepages, groundwater levels, flowing wells, chemical quality of water, natural vegetation, salt precipitates, quality of crops, soap holes, and moist and dry depressions.

Mapping and interpretation of field phenomena have been carried out in a section of the Ghostpine Creek valley in a Prairie environment. The relief is gently rolling, the geology is simple, and the climate is cold, humid, and continental. The area of the “north flow-systems” is apportioned as follows: 26 per cent underlain by downward flow; 42 per cent underlain by a mid-line area; and 32 per cent underlain by upward flow.

Noting that groundwater flow is nearly parallel to the water table in the vicinity of the mid-line these results comply with the above-mentioned theory of groundwater flow distribution in small drainage basins. Thus, the method is suggested for: 1. A reconnaissance study of the groundwater regime in certain areas, and 2. Specific problems related to groundwater in a Prairie environment, such as: finding suitable locations for dug-out type water supplies, estimating prospects for slough-draining and irrigation, and explanation of the development of certain soil types. For such purposes, the method appears to be competitive with test drilling.     

COMPUTATION OF INTERVAL VELOCITIES FROM COMMON REFLECTION POINT MOVEOUT TIMES FOR n LAYERS WITH ARBITRARY DIPS AND CURVATURES IN THREE DIMENSIONS WHEN ASSUMING SMALL SHOT-GEOPHONE DISTANCES*

It is well known that interval velocities can be determined from common-reflection-point moveout times. However, the mathematics becomes complicated in the general case of n homogeneous layers with curved interfaces dipping in three dimensions. In this paper the problem is solved by mathematical induction using the second power terms only of the Taylor series which represents the moveout time as a function of the coordinate differences between shot and geophone points. Moreover, the zero-offset reflection times of the nth interface in a certain area surrounding the point of interest have to be known. The n—I upper interfaces and interval velocities are known too on account of the mathematical induction method applied. Thus, the zero-offset reflection raypath of the nth interface can be supposed to be known down to the intersection with the (n—1)th interface. The method applied consists mainly in transforming the second power terms of the moveout time from one interface to the next one. This is accomplished by matrix algebra. Some special cases are discussed as e.g. uniform strike and small curvatures.