Deep Earth Structure

This paper discusses error analysis as one source of evidence for an overall theory of second language acquisition. Four related areas which form the context for error analysis are discussed in relation to second language learning and the goals and methodology of error analysis; (1) theories of the nature of language which determine theories of error analysis; (2) the study of language systems in contact, which seems to indicate that syntax is subordinate to semantics; (3) the learning of linguistic systems, divided into learning the code (sentence) and learning how to use the code; and (4) the use of linguistic systems in communication, concerned with the nature of the learner's "utterances," in contrast to "sentences." Although the present study is not considered definitive, it is believed that with further study error analysis will greatly influence attitudes toward language-teaching problems. (AM)

The field of English for specific purposes (ESP), which addresses the communicative needs and practices of particular professional or occupational groups, has developed rapidly in the past forty years to become a major force in English language teaching and research. ESP draws its strength from an eclectic theoretical foundation and a commitment to research-based language education which seeks to reveal the constraints of social contexts on language use and the ways learners can gain control over these. In this chapter, I will briefly point to some of the major ideas and practices that currently influence ESP, focusing on needs analysis, ethnography, critical approaches, contrastive rhetoric, social constructionism, and discourse analysis. I then go on to look briefly at some of the effects ESP has had on language teaching and research, arguing that it has encouraged teachers to highlight communication rather than language, to adopt a research orientation to their work, to employ collaborative pedagogies, to be aware of discourse variation, and to consider the wider political implications of their role. Together these features of ESP practice emphazise a situated view of literacy and underline the applied nature of the field.

This chapter summarizes the arguments for and against large-scale chemical differentiation of the mantle and examines the variations in mineral chemistry that need to be accounted for when placing constraints on the compositional and thermal structure of the lower mantle using seismic velocity observations. Various lines of evidence have been used to argue that the lower mantle is chemically distinct in major elements from the upper mantle. One of the few approaches that may clarify this would be to compare observed seismic velocities with estimates computed from mineral physical models. Building a realistic model for the effects of composition on the seismic velocities of lower mantle minerals remains a key goal in mineral physics. The dominant lower mantle minerals are all solid solutions. An important aspect of measured bridgmanite Fe3+ contents is that they appear to be nominally independent of oxygen fugacity.

Currently popular ideas about the Earth's interior have developed almost entirely on the basis of physics. In the spirit of the United Nations' designation of 2011 as the International Year of Chemistry, I unify chemical and physical inferences for Earth-matter below the depth of 660 km. I relate by fundamental mass ratio relationships the internal parts of that region with corresponding enstatite chondrite parts, providing a quantitative basis for understanding the "seismically rough" matter at the core mantle boundary, D'', as arising from Earth-core precipitates, the "core-floaters", CaS and MgS. I suggest that the ultra-low velocity zone consists of CaS.

A ground acceleration map is needed as a consideration in building construction. Therefore, a good ground motion attenuation model is needed to predict the condition in the field properly. This study discusses ground motion attenuation models that are appropriate for West Sumatra and Bengkulu based on distant subduction interface and intraslab earthquakes from 9 attenuation models. The ground motion data in this study are from 13 Meteorological, Clima-tological, and Geophysical Agency's (BMKG) accelerograph sensors that are located in West Sumatra and Bengkulu regions from 2012 to 2017 with a distance of less than 1000 km from the earthquake sources, magnitude range of 4.1-6.4 for subduction interface earthquakes, and 4.1-6.5 for subduction intraslab earthquakes. The results show that the ground motion attenuation model from Kanno et al. (2006) has the best result with an RMSE value of 0.46 for subduction interface earthquakes and the model from Bernal et al. (2012) with RMSE value of 0.49 for subduction intraslab earthquakes.

The composition and state of Earth's core, located deeper than 2,900 km from the surface, remain largely uncertain. Recent static experiments on iron and alloys performed up to inner core pressure and temperature conditions have revealed phase relations and properties of core materials. These mineral physics constraints, combined with theoretical calculations, continue to improve our understanding of the core, in particular the crystal structure of the inner core and the chemical composition, thermal structure and evolution, and possible stratification of the outer core.

Research on constraint-based grammar frameworks has focused on syntax and semantics largely to the exclusion of phonology. Likewise, current developments in phonology have generally ignored the technical and linguistic innovations available in these frameworks. In this paper we suggest some strategies for reuniting phonology and the rest of grammar in the context of a uniform constraint formalism. We explain why