Geology topics
Publications and source records attributed to H. Spall.
I have been editor of Earthquakes and Volcanoes for the last 16 years. Since I will soon be handing over the reins to a consortium of editors who will produce the magazine at the USGS National Earthquake Information Center in Golden, Colorado, I thought I would offer a tetrospective view of editing a magazine designed for a diversified audience.
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.
In late 1985 and early 1986 a comet was visible to the Earth that has been observed for over 2000 years. One of the most famous of celestial visitors, Comet Halley appeared last in 1910 and will not be seen again until the year 2061. the comet has been the focus of intense studies during the International Halley Watch. A fleet of Soviet, Japanese and European spacecraft was launched specifically for a direct encounter with the comet in March of this year; numerous ground-based astronomical observations are being made, while other investigations are being made from Earth-, Venus- and interplanetary-orbits. In short, Comet Halley will have been one of the most significant scientific occasions of the decade. In 1705 Edmund Halley, Professor of Geometry at Oxford University, collected and organized a mass of information on comets observed in 1531, 1607, and 1682, a task for which he had an uncommon genius. He was able to show that the comets had very similar orbits, and correctly drew the conclusion that they were the same object and more importantly that comets could therefore be periodic. He predicted that this comet would again be visible from the Earth in 1759. Since then it has been known as Halley's comet and it has played a significant role in the development of astronomy.
The abrupt disappearance of all the dinosaurs about 65 million years ago, along with perhaps half the plant species and other animals, has been one of the great geological mysteries. Clues to the cause of these extinctions have been scarce and open to many interpretations. But all this may be changing. Mass extinctions have been very much in the news in the last few years, triggered in large part by the proposal that the extinction of the dinosaurs and marine animals was caused by a catastrophic collision between the Earth and an extra-terrestrial body (bolide). Recently an equally contentious suggestion has been made that mass extinctions have swept the Earth every 26 to 31 million years for at least the last 250 million years-caused by encounters with some kind of extra-terrestrial object such as one of the asteroids or the comets.
It is dawn on a June morning in Siberia in 1908. The sky is cloudless, but even in summer this part of Russia the cold at dawn takes your breath away. Fur-clad nomads are beginning to herd their sheep and goats towards lush grazing on the banks of the river-one of the thousands that drift sluggishly across Siberia's vast featureless wilderness towards the Arctic Ocean. Swans glide in the dark shallows of the river. A phalanx of ducks spears into a nearby swamp and sends up a black cloud of ferocious mosquitoes; they settle again around a herd of reindeer browsing on the river bank. Here where the tiaga, the forbidding Siberia forest, obscures the sun, the cold is a sharp as the flint in the river bed. It cuts the farmer who has just emerged from his log cabin. He halts on the steps to decide whether this first task of the day will be to mend the plough that was broken yesterday when he dug too deep and reached permanently frozen ground, or whether he will hunt for rabbit for the evening meal; instead he lights his pipe. Two families of nomads are still asleep in their tents, the air strong with the scent of wet dog as the ice melts on their furs. At a trading post, trappers squabble over the price of ermine and sable pelts. On the edge of the settlement a tramp with pots and pans jingling on his back sets off on his day's journey to the nearest village, twenty miles away. At the edge of the village, a boatman pushes off from the river bank for his first crossing of the day, the crescent-shaped hull of his boat overloaded with squawking chickens, snarling dogs and silent peasants. Without warning there is a blinding blue flash in the sky, followed by a roar and a searing blast of heat; there is a thunderous clap, the ground shudders, and this air is filled with fire, black smoke and debris. The boat disintegrates, hurling men and animals into the freezing river. The farmer's shirt is scorched off his back; the tramp is blown off his feet, his ports and pans scattering like shrapnel. One of the trappers standing in the doorway of the trading post is knocked unconscious, overcome by the searing heat; the tents of the nomads are torn loose, the men and dogs inside being rolled over the ground like leaves in a gale. All that remain of the reindeer are charred carcasses. The forest has been turning into a crackling inferno, and a black fireball rises into the air.
For thirty years the name of Karl V. Steinbrugge has been synonymous with the Insurance Services Office in San Francisco. There he was in charge of their earthquake engineering and research activities for the United States, and his work included detailed engineering investigations of the probable earthquake damage to structures as well as studies of actual earthquake effects. trained as a civil and structural engineer, Steinbrugge was on faculty of the University of California at Berkeley for 28 years, retiring as a Professor of Structural Design. He has served on numerous national and international committees on earthquake hazards, and he is now a consulting structural engineer, specializing in earthquake hazard evaluation. At the present moment he is chairman of an independent panel of the Federal Emergency Management Agency that is reviewing the National Earthquake Hazards Reduction Program. Henry Spall recently asked Steinbrugge some questions about his long career.
No part of New Zealand is far from a known earthquake origin. The magnitude 7.9 earthquake of 1931 at Hawke's Bay, North Island, on February 3, 1931, was the most serious event recorded in New Zealand hsitory. It was responsible for 256 deaths. The Modified Mercalli intensity reached XI in Napier, a city of 35,000 people, and hence, caused considerable destruction to property.
Earthquakes occur at the following three kinds of plate boundary: ocean ridges where the plates are pulled apart, margins where the plates scrape past one another, and margins where one plate is thrust under the other. Thus, we can predict the general regions on the earth's surface where we can expect large earthquakes in the future. We know that each year about 140 earthquakes of magnitude 6 or greater will occur within this area which is 10% of the earth's surface. But on a worldwide basis we cannot say with much accuracy when these events will occur. The reason is that the processes in plate tectonics have been going on for millions of years. Averaged over this interval, plate motions amount to several mm per year. But at any instant in geologic time, for example the year 1982, we do not know, exactly where we are in the worldwide cycle of strain build-up and strain release. Only by monitoring the stress and strain in small areas, for instance, the San Andreas fault, in great detail can we hope to predict when renewed activity in that part of the plate tectonics arena is likely to take place. -from Author
Mr.Birge M. Clark, an architect in Palo Alto, Calif., was living in Palo Alto at the time of the 1906 earthquake. his father-in-law was Professor S. D. Townley, well known for his 1939 compilation, with Maxwell W. Allen, of earthquakes along the Pacific coast from 1769 to 1928.
On a stormy night in October 1836, H.M.S Beagle hove to and dropped anchor at Falmouth, a remote harbor in southwest England. Charles Darwin, the ship's naturalist, came ashore to take the mail coach to Shrewsbury. This was inauspicious end to an epic 5-year voyage around the coast of South America, the results of which were to have a tumultuous impact on scientific thought that has lasted to this day.
Sir Harold Jeffreys is a world authority in theoretical geophyiscs. hew as born in Northumbria (northeast of England) and educated at Armstrong College (now the University of Newcastle-upon-Tyne) and Cambridge University. He is now a Senior Fellow of St.John's College, Cambridge. He has published over 300 scientific papers and is the author of 7 books, including Theory of Probability and Mathematical Physics (with his wife, Lady Bertha Swirles Jeffreys) . Sir Harold has made innumerable theoretical contributions to seismology. Many of these are documented in his book The Earth , which has been published in six editions. His papers have recently been collated by Gordon and Breach (Publishers) into six volumes, Collected Papers on Sir Harold Jeffreys on Geophyiscs and other Sciences. Some idea of the breadth of this research can be seen from the individual volume titles: "Theoretical and Observational Seismology," "Observational Seismology," "Gravity," "Dissipation of Energy and Thermal History," "Astronomy and Geophysics," and "Matematics, Probability and Miscellaneious Other Sciences."
Dr. Alberto A. Giesecke is head of the Instituto Geofisico del Peru, in Lima, Peru, and Director of Centro Regional de Sismologia para America del Sur (CERESIS). The center is dedicated to the coordination and promotion of earthquake hazard mitigation. Dr. Giesecke was President of the National Research Council of Peru and currently is a member of the Board of Directors of the National Institute for Industrial Technological Research and Standards and of the National Institute for Research and Training in Telecommunications. He presided over the Organizing Committee for the General Assemblies of the International Association for Seismology and Physics of the Earth's interor and the International Union for Radio Science held in Lima, Peru, in 1973 and 1975, respectively.
Dr. Anton L. Hales is a leading seismologist who has just retired as Director of the Research School of Earth Sciences at the Australian National University (ANU), Canberra. Prior to that, he headed the Geosciences Division at the University of Texas at Dallas, and, before that, he was Director of the Bernard Price Institute of Geophysical Research at the University of the Witwatersrand Johannesburg, South Africa. he is about to step down as President of the International Geodynamics Commission. Dr. Hales' research has involved marine geophysics, the travel times of seismic waves, and the structure of the Earth's crust and upper mantle.
Dr. I. L. Nersesov is a seismologist with the Institute of Physics of the Earth, Academy of Sciences of the U.S.S.R., Moscow. He is one of the leaders in the Soviet national program of earthquake prediction.
Day by day monitoring of the Mount St. Helens Volcano. These are four scenarios, very different scenarios, that can occur in a average week at Mount St. Helens. Ranging from eruptions of gas and to steam to eruptions of ash and pyroclastic flows to even calm days. This example of monitoring illustrates the differences from day to day volcanic activities at Mount St. Helens.
Charles F. Richter, renowned seismologist, is a professor emeritus at the California Institue of techonology (Caltech). He is best known to the public for the Richter magnitude scale; but he is equally recognized in the scientific community for many other contributions to seismology including his books Elementary Seismology (1958) and Seismicity of the Earth (coauthored in 1954 with Beno Gutenberg).
The International Seismological Centre had its origins when the British seismologist Professor John Milne returned to England from Japan in 1895 to retire at Shide on the Isle of Eight. In cooperation with the British Association for the Advancement of Science, Milne had set up a number of seismographic stations around the world and, while Tokyo, had published a Catalogue of 8,33 Earthquakes Recorded in Japan, 1885-1892.
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