摘要:

Mount Rainier, the highest (4392 m) volcano in the Cascade Range, towers over a population of more than 2.5 million in the Seattle‐Tacoma metropolitan area, and its drainage system via the Columbia River potentially affects another 500,000 residents of southwestern Washington and northwestern Oregon (Figure 1). Mount Rainier is the most hazardous volcano in the Cascades in terms of its potential for magma‐water interaction and sector collapse. Major eruptions, or debris flows even without eruption, pose significant dangers and economic threats to the region. Despite such hazard and risk, Mount Rainier has received little study; such important topics as its petrologic and geochemical character, its proximal eruptive history, its susceptibility to major edifice failure, and its development over time have been barely investigated. This situation may soon change because of Mount Rainier's recent designation as a “Decade Vol

ISSN:0002-8606    

DOI:10.1029/91EO00143

年代:1992

数据来源: WILEY

摘要:

The National Oceanic and Atmospheric Administration's budget request of $1.7 billion for fiscal year 1993 is “the best budget we have presented to date,” said John Knauss, Under Secretary for Oceans and Atmosphere, U.S. Department of Commerce. It is an increase of 7.8% over fiscal 1992. NOAA's proposed budget focuses on four major areas: the modernization of the National Weather Service, improving predictions of global change, understanding coastal ocean processes, and managing marine fisheries.The budget “reflects our conviction that we are working to assure the president's belief in the interconnectedness of the environment and the economy,” particularly in the weather service and fisheries programs, said Knauss, testifying before the Senate Appropriations Subcommittee on Commerce, Justice, State, the Judiciary and Related Agencies on

ISSN:0002-8606    

DOI:10.1029/91EO00145

年代:1992

数据来源: WILEY

摘要:

The topic of watershed hydrology, is, in the author's words, “…simply the study of the movement and storage of water on and in the context of the natural land unit of the hydrosphere, the watershed.” The organizational structure ofWatershed Hydrologyhas storage and process as a focus, and this theme is reflected throughout. Chapter 1 provides an overview of the hydrologic cycle and some basic concepts of storage in the hydrologic cycle. Hydrologic processes are briefly defined, and several misconceptions about the hydrologic cycle are noted. Sites of storage within the hydrologic cycle (depression storage, channel storage, detention storage, groundwater storage, retention storage, and vegetation storage) are briefly introduced, along with the concept of a wate

ISSN:0002-8606    

DOI:10.1029/91EO00146

年代:1992

数据来源: WILEY

摘要:

Joselyn and Tsurutani[1990] andKamide and Joselyn[1991] suggested ways of improving the existing definition of Storm Sudden Commencements (SSCs) and Sudden Impulses (SIs). Because those two articles apparently present controversial opinions on some aspects of SSCs, we would like to point out some difficulties in defining SSCs that we think explain such a controversy.

ISSN:0002-8606    

DOI:10.1029/91EO00148

年代:1992

数据来源: WILEY

摘要:

A special SPA: Magnetospheric Physics session dedicated to the recovery phase of substorms is being planned for the AGU 1992 Fall Meeting. Substorms have provided an important focus for magnetospheric research for nearly 3 decades, and continue to do so today. Of the three phases (growth, expansive, and recovery) that constitute a substorm, the growth and expansive phases have received the most attention, and a fairly good understanding of them has developed.In contrast, the recovery phase has received scant attention. Perhaps that is because it lacks the dramatic auroral and geomagnetic effects that mark the expansive phase at Earth and the similarly impressive particle and magnetic field effects that mark the growth phase to expansive phase transition at geosynchronous orbit. The recovery phase was originally defined as the period when auroras, having advanced far toward the pole during the expansive phase, become less intense and retreat back toward the auroral oval. Wavy structures—omega bands—and pulsating intensities often characterize the recovery phase auroras. It has become customary, also, to define the recovery phase as that period when the Auroral Electrojet (AE) index is subsiding from the peak value it reached during the substorm. These two definitions, probably not altogether compatible, may identify somewhat different periods of a substorm. There is no obvious feature in geosynchronous observations that has been specifically identified with the recovery ph

ISSN:0002-8606    

DOI:10.1029/91EO00149

年代:1992

数据来源: WILEY

摘要:

The Apia Magnetic Observatory has been making recordings on the same site since 1905. As a result, it has one of the longest data sets for one site of any observatory in the world. Work is also done in meteorology, seismology, hydrology, and geology at the observatory. Despite damage to the observatory's instrumentation and facilities resulting from two tropical storms, it is collecting data once again.At the beginning of 1990, western Samoa was devastated by tropical cyclone Ofa. A great deal of damage was done at the Apia Observatory, which is located at the end of a peninsula protruding out into the lagoon. One office building was destroyed when it was washed off its foundations. The outer roof was blown off the magnetic variometer house and various amounts of damage were done to other buildings. Besides damage to the buildings, a great deal of damage was done to the instruments from salt water and spray, particularly to both the variometers and absolute instruments used in the geomagnetic program.

ISSN:0002-8606    

DOI:10.1029/91EO00150

年代:1992

数据来源: WILEY

摘要:

Over a year into the International Decade of Natural Disaster Reduction (IDNDR), significant steps were taken at the International Union of Geodesy and Geophysics (IUGG) assembly in Vienna last August to develop major activities in a number of associations. In particular, a broad program on the reduction of earthquake hazards was adopted by the International Association of Seismology and Physics of the Earth's Interior (IASPEI).First, a major IASPEI report on the proposed goals and activities of the association, “Minimizing Earthquake Vulnerability” (IASPEI Committee for IDNDR, 29 pp., 1991), was adopted. This report sets out program goals and an organization for dealing with proposals and allocating resources. It contains twenty‐two recommendations that cover all aspects of seismological risk reduction and associated research and education. At the IUGG assembly, a keynote lecture on the decade and its relation to seismological work was given by R. Hamilton, director, United Nations‐IDNDR Secretariat in

ISSN:0002-8606    

DOI:10.1029/91EO00152

年代:1992

数据来源: WILEY

摘要:

Nearly 100 scientists from 11 nations gathered to discuss integrated research in forest watersheds at the Gordon Research Conference, “Hydrological‐Geochemical‐Biological Interactions in Forested Catchments,” held from July 1 to 5, 1991, in Plymouth, N.H. The conference was the first‐ever on this topic, and it was held to address newly emerging research questions, to highlight recent advances in watershed science, and to bring biologists and ecologists into discussions discussions of catchment hydrogeochemical function. R. Church (U.S. Environmental Protection Agency, Corvallis, Oreg.) and G. Hornberger (University of Virginia) served as chair and vice‐chair, respectively, of the

ISSN:0002-8606    

DOI:10.1029/91EO00154

年代:1992

数据来源: WILEY

摘要:

A 1991 AGU Fall Meeting session, Precipitation in Topographically Diverse Regions, focused on the understanding and modeling of precipitation in regions with significant topography, concentrating on the effect of topography on precipitation. Contributions ranged from detailed mesoscale atmospheric models to statistical approaches.Two papers presented detailed physical modeling. A. P. Barros and D. P. Lettenmaier described their work, consisting of a threedimensional finite element model based on the measurement of moist static energy. Application of the model in the Olympic and Cascades mountains demonstrated its potential to model monthly precipitation totals to within 15%. F. Giorgi described some of the work being done at NCAR that is focusing on the regional impacts of global climate change. This work uses a mesoscale meteorological model (Penn State/NCAR MM4) embedded within a general circulation model. There were three papers from the USGS/Colorado State group that described work involving the RHEA‐CSU orographic precipitation model that has been coupled with the USGS/s distributed parameter Precipitation Runoff Modeling System (PRMS). The orographic precipitation model has been integrated into a geographic information system to facilitate the use of digital elevation data. The PRMS is based on the concept of hydrologic response units, and the results presented illustrated the scale's sensitivity to these. When rectangular boxes were used instead of the usual response units defined by streams and drainage divides, there was no appreciable degradation in the quality of the simulation. The size and number of response units appears to be more crucial than whether they are demarcated by drainage divides and streams or simply arbitrar

ISSN:0002-8606    

DOI:10.1029/91EO00156

年代:1992

数据来源: WILEY