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The following article is a reconstruction of events surrounding the deaths of a party of Hawaiian warriors in 1790 on Kilauea Volcano. It suggests that they were killed by a very hot, ash-free, base-surge cloud that rushed from the volcano. Much more recently than that, in the early morning hours of November 29, 1975, the largest earthquake in more than 100 years struck the southern part of the Island of Hawaii, causing widespread faulting and subsidence, an eruption at the summit of Kilauea Volcano, the loss of at least one life, and widespread damage to property. The effects of this earthquake are still being analyzed by the staff of the Geological Survey's Hawaiian Volcano Observatory, but preliminary results indicate that much of the south flank of Kilauea Volcano moved seaward in an abrupt, slump-like manner. The eruption that followed was small by the usually Kilauea standards and is regarded as a leakage of lava from the volcano's underground reservoir system in response to the effects of the earthquake. A more detailed account of these events will be included in a future issue of the Earthquake Information Bulletin.
During the last decade, earthquake engineering research in Peru has been carried out at the Catholic University of Peru and at the Universidad Nacional de Ingeniera (UNI). The Geophysical Institute (IGP) under the auspices of the Organization of American States (OAS) has initiated in Peru other efforts in regional seismic hazard assessment programs with direct impact to the earthquake engineering program. Further details on these programs have been reported by L. Ocola in the Earthquake Information Bulletin, January-February 1982, vol. 14, no. 1, pp. 33-38.
Geothermal energy-from heat deep inside the Earth- is a vast potential source of power. This article is the second part of a series on geothermal energy, the first part of which was in volume 8, number 1, of the Earthquake Information Bulletin (January-February 1976). Part 1 of this series described the categories of the geothermal resource base.
Can your friend's relative really predict earthquakes? Or how about that fellow in the mountains who has always liked geology, does he have the answer to the "when" of earthquakes? And if these people do actually predict an earthquake, is it a lucky guess or are they tuned in to something? A lucky guess would be interesting; 1 correct guess in 100 tries is hardly prediction. But 90 out of 100-now that's prediction! As part of an attempt to separate useful predictions from inaccurate guesses, we have kept score on earthquake predictions from all sources brought to our attention over the past year and a half. The program was outlined in "Earthquake Prediction;Fact and Fallacy" by Roger N. Hunter (Earthquake Information Bulletin, vol. 8, no. 5, September-October 1976, p. 24-25). The program attracted a great deal of public attention, and, as a result, our files now contain over 2500 predictions from more than 230 different people.
The results from seismological studies that are used by the engineering community are just one of the benefits obtained from research aimed at mitigating the earthquake hazard. In this issue of Earthquake Information Bulletin current programs in seismology and earthquake engineering, seismic networks, future plans and some of the cooperative programs with different internation organizations are described by Latin-American seismologists. The article describes the development of seismology in Latin America and the seismological interest of the OAS. -P.N.Chroston
The San Andreas fault is part of the boundary between the Pacific and North American crustal plates. In California, movements of about 3 centimeters per year are currently taking place along the fault, although plat tectonic models suggest a faster rate of 5 cm/yr may be the average over a longer period of time and a broader area. There are two distinct ways in which movement on the San Andreas occurs. Along most of the fault, slip occurs during infrequent great earthquakes. Examples of these in historic time are the 1857 Fort Tejon and the 1906 San Francisco events. Along these portions of the fault, it appears that, during most of the intervening period between great earthquakes, no slip and few microearthquakes occurred. Strain appears to accumulate at shallow depths in a narrow (50 kilometer) zone adjacent to the fault. Along a 200-km stretch in central California, however, continuous slip occurs with no observable accumulation of strain. Although there is a high level of microseismicity here, earthquakes larger than magnitude (M) 6 are unknown, and most of the slip occurs aseismically. (Several articles in the Earthquake Information Bulletin in 1978 have covered this topic.) At the northern end of this creeping zone, the microseismicity and the slip gradually taper to zero over a distance of about 100 km. This segment is the site of frequent earthquakes (every 5-10 years) having magnitudes of 5.5 and less. At the southern end, near the town of Parkfield, the transition occurs in about 40km. This zone is the site of recurring earthquakes of about magnitude 6.
In an article in the last issue of the Earthquake Information Bulletin ("Earthquakes and Plate Tectonics," by Henry Spall), we saw how 90 percent of the world's earthquakes occur at the margins of the Earth's major crustal plates. however, when we look at the distribution of earthquakes in detail, we see that a number of nearly aseismic regions, or seismic gaps, can be found along the present-day plate boundaries. Why is this? And can we regard these areas as being more likely to be the sites for future larger earthquakes than those segments of the plate boundaries that have ruptured recently.
In recent years, we have made significant progress in being able to recognize the long-range pattern of events that precede large earthquakes. For example, in a recent issue of the Earthquake Information Bulletin, we saw how the pioneering work of S.A. Fedotov of the U.S.S.R in the Kamchatka-Kurile Islands region has been applied worldwide to forecast where large, shallow earthquakes might occur in the next decades. Indeed, such a "seismic gap" off the coast of Alaska was filled by the 1972 Sitka earthquake. Promising results are slowly accumulating from other techniques that suggest that intermediate-term precursors might also be seen: among these are tilt and geomagnetic anomalies and anomalous land uplift. But the crucial point remains that short-term precursors (days to hours) will be needed in many cases if there is to be a significant saving of lives.
In 1811-12, a series of disastrous earthquakes struck the southeast Missouri region (see "The Mississippi Valley earthquakes of 1811 and 1812" by Otto W. Nuttli in the Earthquake Information Bulletin, March-April 1974). Earthquake activity continues in the area at present, showing that the seismic hazard is still there. We know little about the relationship between seismicity and the tectonic character of this region. The hypocenters of earthquakes are scattered. The near-surface features themselves are obscured by the several hundred feet alluvium and other quaternary sediments of the Mississippi embayment. No active faults have been mapped in the area. Supported by the U.S Geological Survey, my colleagues Mark Kramer, Gerard Fischer, Stephen Schaefer, Sean Morrissey, and I have recently established a microearthquake network in the New Madrid seismic zone. The network has been in operation for only 21 months, yet we have already been able to show, from the hypocenters located so far, that earthquakes in this region occur along linear zones, which we believe corespond to seismically active faults.
Professor Bruce Bolt was educated in Australia and first came to the United States in 1960 on a Fulbright Fellowship to the Lamont Geological Observatory of Columbia University. In 1963 he was appointed Director of the Seismographic Stations at the University of California at Berkeley. In June 1988, he steps down as Director but his association will continue as Professor of Seismology. Henry Spall interviewed him again 10 years after a 977 interview published in the Earthquake Information Bulletin.
Estimates of the magnitudes of annual peak streamflows with annual exceedance probabilities of 0.5, 0.2, 0.1, 0.04, 0.02, 0.01, and 0.002 (equivalent to recurrence intervals of 2-, 5-, 10-, 25-, 50-, 100-, and 500-years, respectively) were computed for 391 streamgages in Ohio and adjacent states based on data collected through the 2015 water year. The flood-frequency estimates were computed following guidance outlined in Bulletin 17C, developed by the Advisory Committee on Water Information. The Bulletin 17C guidelines retain the basic statistical framework of the superseded Bulletin 17B guidelines; however, the Bulletin 17C guidelines add several enhancements including an improved method of moments approach for fitting the log-Pearson Type III (LPIII) distribution to the flood peaks (called the expected moments algorithm), a generalization of the Grubbs Beck low-outlier test (called the Multiple Grubbs Beck test) that permits identification of multiple potentially influential low floods, and new methods for estimating regional skew and uncertainty. Equations for estimating flood-frequency characteristics at ungaged sites on rural, unregulated streams in Ohio were developed with a two-step process involving ordinary least-squares and generalized least-squares regression techniques. Data from 333 streamgages with 10 or more years of unregulated record were screened for redundancy and a regression dataset was selected that was composed of flood-frequency and basin-characteristic data for 275 streamgages in Ohio and adjacent states. Two sets of equations were developed—one set, referred to as the “simple model,” uses regression region and drainage area as regressor variables, and a second set, referred to as the “full model,” uses regression region, drainage area, main-channel slope, and the percentage of the watershed covered by water and wetlands as regressor variables. The average standard errors of prediction ranged from about 40.5 to 46.5 percent for the simple-model equations and from about 37.2 to 40.3 percent for the full-model equations. For sites meeting the rural, unregulated criteria, flood-frequency estimates determined by means of LPIII analyses are reported along with weighted flood-frequency estimates, computed as a function of the LPIII estimates and the regression estimates. For sites with homogenous periods of regulation, flood-frequency estimates determined by means of LPIII analyses are reported. Ninety-five percent confidence limits are reported for all estimates. Values of regressor variables were determined from digital spatial datasets by means of a geographic information system (GIS). The GIS datasets and the new full-model equations have been incorporated into Ohio’s StreamStats application, a web-based, GIS-backed system designed to facilitate the estimation of streamflow statistics at ungaged locations on streams. Seasonal patterns in peak flows were assessed for 295 streamgages in Ohio. Annual peak flows occurred most frequently between January and April, with March having the highest frequency of occurrence. The month with the fewest number of annual peaks was October. Peak-of-record flows occurred most frequently in March, followed by January (months in which two of Ohio’s most severe widespread floods in recent history occurred). None of the peak-of-record flows occurred in October and only two occurred in November. Temporal trend in annual peak flows were assessed for 133 streamgages on unregulated streams in Ohio with 30 or more years of systematic record. Trends were assessed by computing the rank correlation (as measured with the two-sided Kendall’s tau statistic) between time and annual peak flows. Weak but statistically significant trends were indicated at 15 of the 133 streamgages. Of the 15 streamgages with significant trend in annual peak flows, 12 had an upward trend (positive tau) and 3 had a downward trend (negative tau). All 12 streamgages with positive tau values were at latitudes north of 40°33', and streamgages with negative tau values were at latitudes south of 40°33'.
This bulletin is designed to inform interested personnel about training available through the Water Resources Division of the U.S. Geological Survey during the period October 1981 through September 1982. The information in this bulletin also can assist supervisors and training officers in developing a coordinated, efficient training program for the personnel for whom they are responsible. The objective of the Water Resources Division training program is to provide specialized training in many phases of hydrology and other subjects related to water-resources investigations. The courses featured in this bulletin are on specialized subjects that are not generally available elsewhere, including the latest developments in applications of ground-water, surface-water, and water-quality hydrologic methods in the field and in the laboratory. The training described herein provides: (1) rapid application of new research results to increase the skills of personnel, and (2) provides newly recruited personnel with special training skills and methods required in water-resources investigations. These courses will assist personnel in learning, reviewing, and expanding their knowledge of technical operations involved in various phases of hydrology and related subjects, and also will develop an overall insight into the broad field of water-resources work.
In the middle of the 15 th century, shortly after Gutenberg’s invention of printing using individual lead type, the first illustrated broadsides (or broadsheets) began appearing in southern Germany. Usually printed on one side of a sheet of paper, they consisted of a woodcut illustration, sometimes colored, either by hand or by stencil, and several columns of text, often in verse. The appeal of the publications to the mass reader was often stimulated by sensationalism in word and picture, somewhat like that purveyed today’s tabloid press. What follows are woodcuts and portions of the text from 16 th to 17 th century broadsheets that describe earthquakes and volcanic eruptions. This article is an excerpt from Deresiewicz, H., 1982, Some 16th century European earthquakes as depicted in contemporary sources: Bulletin Seismological Society of America, vol. 72, p 507-523.
Skip Nav Destination RESEARCH ARTICLE | JULY 01, 1986 Effect of height and orientation (microclimate) on geomorphic degradation rates and processes, late-glacial terrace scarps in central Idaho KENNETH L. PIERCE ; STEVEN M. COLMAN Author and Article Information GSA Bulletin (1986) 97 (7): 869–885. https://doi.org/10.1130/0016-7606(1986)97<869:EOHAOM>2.0.CO;2 Article history Standard View 2.0.CO;2" data-doctype="contentPdf" data-article-id="188507" data-mce-href="https://pubs.geoscienceworld.org/gsa/gsabulletin/article-pdf/97/7/869/3434736/i0016-7606-97-7-869.pdf"> Open the PDF for in another window Cite Share Icon Share Permissions Abstract Terrace scarps can serve as a nearly ideal natural laboratory for the study of the evolution of slopes. This paper examines the effects of scarp size (height) and orientation (microclimate) by keeping constant variables such as age, lithology, and regional climate. If a scarp degrades as a closed system, and downslope movement is directly proportional to surface gradient , the evolution of the scarp is modeled by the diffusion equation. For a group of scarps of same age and known starting angle, the diffusion-equation model predicts the relation between maximum scarp angle (𝛉) and scarp height ( h ). Late Pleistocene terrace scarps now as steep as 33.25°, as well as measured angles of repose for sand and gravel, require a starting angle as steep as 33.5°. For latest Pleistocene Idaho and Utah scarps, as h increases, 𝛉 is gentler (more degraded) than modeled by the diffusion equation with a constant rate coefficient. The degradation-rate coefficient ( c ) increases tenfold with scarp height; it should not change with scarp height if downslope movement is solely determined by surface gradient (to the first power). Soil wash appears to be responsible for this departure from the diffusion-equation model, for transport rate by soil wash is a function of scarp size (height). South-facing scarps are less vegetated and more degraded than north-facing scarps. For scarps 2 m high, the degradation rate ( c *) on S-facing scarps is 2 times that on N-facing scarps; for 10-m scarps, it is 5 times. The observed dependence of the rate coefficient c * on scarp height can be removed by normalizing c * to values for west-facing scarps of the same height. The residual c * values calculated by this method correlate well with differences in incident solar radiation resulting from the different scarp orientations and maximum gradients. This correlation demonstrates the importance of orientation on slope processes and their rates through the differences in freeze-thaw cycles, soil moisture, and vegetative cover. Scarp morphology may be used to estimate age, if one accounts for the effects of climate and for scarp height, orientation, and lithology. For example, using the dated Bonneville shoreline scarps for calibration and comparing only scarps of equal height, we estimate the Drum Mountains fault scarps to be 9,000 yr old. This age is about twice that produced by previous diffusion-equation calculations that have not accounted for the height as we have here, but it is the same as independent geologic estimates of their age.
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No abstract available at this time
No abstract available at this time