ISSN:0149-0419    

DOI:10.1080/15210608709379551

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

摘要:

The tsunami travel‐time charts that are presently in use by the Tsunami Warning Center were constructed originally in 1948 based on the hydrographic data available in the mid 1940s. Even the revised charts of 1971 made use of essentially the same data. It is shown here that the travel times deduced by these charts could be in error by as much as two hours in some cases. Even worse, the compiled travel times as deduced from these charts are generally greater than the observed travel times, which is a dangerous situation from a tsunami warning point of view.

ISSN:0149-0419    

DOI:10.1080/15210608709379552

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

摘要:

We estimate secular changes in steric sea level in the northeast Pacific Ocean using the 27‐year time series of monthly hydrographic observations for Station PAPA (50°N, 145°W). Linear trends based on the entire data record suggest that steric heights relative to 1000 db are increasing at a rate of 0.93 mm/yr and that 67% of this increase is due to thermosteric changes at depths below 100 m; the smaller halosteric contribution to the steric trend appears to be confined to the upper 100 m. A trend of 0(1 mm/yr) is consistent with estimates of sea level rise based on coastal tide gauge records. However, a critical examination of the results indicates that sea level changes of such small magnitude would be masked by the large (1–10 cm) interannual variability of open ocean steric height. This is verified by recalculation of trends using abridged versions of the data set. We conclude that our trend estimates are still open to question and that the present 27‐year time series is too short to permit accurate resolution of possible climate‐induced changes in global sea level.

ISSN:0149-0419    

DOI:10.1080/15210608709379553

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

摘要:

A computer program has been developed to draw paleo‐continental maps for the period 190 million years ago to the present. The user has the option of specifying the projection and the scale. Maps can be drawn for the globe as a whole, for the northern hemisphere alone, and for the southern hemisphere alone, or indeed for any specified part of the globe. These paleo‐geographic maps are useful for the computation of paleo‐tides, paleo‐ocean circulation studies and climate.

ISSN:0149-0419    

DOI:10.1080/15210608709379554

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

摘要:

Joint probabilities of runup height due to astronomical tides and tsunamis are calculated for five bays on the Pacific Ocean coast of Mexico. Runup heights equaled or exceeded on the average of once per 100 years, and once per 200 years, for those bays, are evaluated. Calculations are based on wave height probabilities obtained from sets of harmonic constituents and tsunami heights recorded during the last 28 years at tidal stations on each location.

ISSN:0149-0419    

DOI:10.1080/15210608709379555

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

摘要:

During May 1985, a comprehensive GPS and acoustic navigation data set was collected off the Monterey, California coast. Three types of GPS units, a LORAN‐C, and a Miniranger operated concurrently with an OCEANO acoustic system to resolve state‐of‐the‐art accuracies for at‐sea geodetic positioning. This report details the acoustic system which displayed baseline errors of only ±0.25 m over distances to 2600 m. Unfiltered point‐to‐point acoustic navigation errors had a standard deviation of ± 1.25 m, which included ship motion errors in addition to surveying errors. Ninety percent of the stations had navigation standard deviations below ±0.75 m The experiment showed that sub‐meter acoustic surveying is the state‐of‐the‐art.

ISSN:0149-0419    

DOI:10.1080/15210608709379556

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

摘要:

Earlier studies on the age of tide dealt mostly with the age of the semi‐diurnal tide in the Atlantic and Pacific Oceans. In these studies, the variations of the age of tide were determined making use of recorded tidal data up to and including the 1960s. In the present study, all available tidal data till the mid 1980s are utilized and the computations were done for the four global oceans: Atlantic, Pacific, Indian, and Arctic. Also, in addition to the age of the semi‐diurnal tide, the age of the parallax and the age of the diurnal tide were determined. The distribution patterns for the positive and negative ages for the semi‐diurnal tide, parallax, and diurnal tide were related whenever possible with the tidal amphidromic point locations and the amplitude ratios S2/M2, N2/M2, and O1/K1.

ISSN:0149-0419    

DOI:10.1080/15210608709379557

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

摘要:

In the recent seismological literature, several articles appeared which suggested that major earthquakes are likely to occur in the near future, in the various seismic gaps around the rim of the Pacific Basin. Although the direct effects of these earthquakes may be confined to local areas, the tsunamis that will generate are expected to travel Pacific Ocean wide and cause great destruction even at far off places around the Pacific Ocean. Here, the various approaches to delineating the tsunami hazard are discussed and some suggestions are made.

ISSN:0149-0419    

DOI:10.1080/15210608709379558

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

摘要:

Geoid heights and vertical deflections derived from satellite radar altimetry contain characteristic signals that may be reproduced and explained by simple models for seamount gravitation acting on the sea surface. Computer algorithms capable of automatic operation and able to detect, approximately locate, and estimate parameters constraining the shape of actual sea‐mounts were written and tested. The computer program which utilized a digital high‐pass filter combined with a roughness sensor was effective in separating the seamount produced geoid undulation/vertical deflection pattern from the remaining data track features, simultaneously detecting and locating along the track such signals. Tests of the algorithm on several SEASAT passes over known bathymetry produced mixed results. Meaningful shape constraints were obtained by matching the geoid anomaly calculated from the seamount model to the actual mean sea level pattern for some seamounts. Results for other seamounts were poor and possible reasons for the failure are discussed. It is concluded that a computerized seamount detection program for radar altimetry data is feasible, but it will have to be more complex than the present one for fully successful operation.

ISSN:0149-0419    

DOI:10.1080/15210608709379559

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

摘要:

Under a joint government/industry program called the Winter Ice Experiment Beaufort Sea (WIEBS), during November and December 1979 and April 1981, two data sets were acquired in the southeastern Beaufort Sea, for the purpose of developing and testing a dynamical/thermodynamical sea ice model. The data sets included meteorological, oceanographic, and sea ice parameters. Also, on a limited scale, ground truthing data were obtained. This paper deals with the data collection aspects of the experiment and their archival.

ISSN:0149-0419    

DOI:10.1080/15210608709379560

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor