Seismometric investigation of the Hawaiian lava column

1920 ◽  
Vol 10 (4) ◽  
pp. 155-275 ◽  
Author(s):  
T. A. Jaggar
Keyword(s):  
General Character ◽  
Volcanic System ◽  
Mauna Loa ◽  
Local Earthquakes ◽  
Earthquake Frequency ◽  
History Of ◽  
Expansion Cooling ◽  
Lava Lakes ◽  
Earthquake Sequences ◽  
Hawaiian Lava

Abstract In Chapter 1, introduction, this article is stated to be concerned with correlations between rising and falling magma and measurement of ground movements. In Chapter 2, on the lava column, the contents are (1) the nature of Hawaiian lava lakes, (2) methods of measurement, (3) the duplex quality of the lava column at the surface, (4) the gas and pressure controls, (5) processes of growing strain, elastic stress and thermochemistry, (6) importance of thermo-chemical controls, (7) lake magma and bench magma, (8) pyromagma, epimagma, hypomagma and perilith, the four elements of a lava column, (9) physical relations of these, (10) the double convectional mechanism, (11) surficial expansion cooling and gas heating, (12) disruptive expansion, (13) the “geyser” effect, (14) clastolith and dermolith, the dead and live lavas, (15) gas release shallow, (16) thermal gradient and oxygen, (17) summary of lava column, (18) the volcanic system, (19) volcanic seismicity due to nine types of stress change, (20) changes of volume, (21) fixed rift surfaces. In Chapter 3 is discussed cyclical lava change. (1) Sensitive earth crust, (2) Perret's hypothesis, (3) Wood's hypothesis, (4) comparison Perret and Wood, (5) direction of stress, (6) analysis general habit of Halemaumau 1912-1916. Chapter 4 treats of the volcanic history of hawaii. (1) The island, (2) the craters: Kohala, (3) Mauna Kea, (4) Hualalai, (5) Mauna Loa, (6) history of origin of Mauna Loa, (7) Kilauea, (8) Kilauea older than Mauna Loa, (9) foundation under Hawaii. Chapter 5 discusses seismometric measurement of slow tilting in hawaii. (1) Excessive tilt, (2) correspondence with lava fluctuation, (3) tilting elsewhere: Cambridge, Massachusetts, (4) tilting in Tokyo, (5) tilts due to water tides, (6) diurnal tilt at Trieste, (7) Galitzin's mention of extreme tilts, (8) volcanic tilting in Japan, (9) Usu-san, (10) Sakurajima, (11) special tilt measurement, Kilauea; the instruments, (12) sources of error, (13) special tilt instrument, (14) method of determining tilt constants, (15) seconds factors adopted, (16) table of daily tilts, (17) method of computing total tilt and direction, (18) general features of table, (19) investigation of temperature effects, (20) table of hourly tilts, (21) analytical table duration northwest and southwest tilts, (22) comparison diurnal tilts elsewhere, (23) parallelism of tilt chart and thermogram, (24) net cumulative tilt not in accord with temperature, (25) summary diurnal temperature effect, (26) table of six-day tilts; general characters, (27) grouping of significant periods, (28) comparison with one-day tilts, (29) curve of tilting for thirty-one weeks, (30) curve of lava rise and fall, (31) comparative fluctuations pyromagma and epimagma, (32) comparison lava and tilting, (33) test of theory of instantaneous correspondence, (34) test of theory of lava lagging, (35) eighteen-day lag agrees for rising lava and east tilt, (36) theoretical discussion of forecasting data, (37) permanent tilt deformation, (38) summary of conclusions concerning tilt, (39) suggested order of causation, (40) nutation stress and the daily tide, (41) supposed northeast tilts, (42) observed phenomena of tumefaction, (43) direct luni-solar warping insufficient. Chapter 6 deals with local earthquakes and tremors. (1) Notes already published, (2) table of earthquake sequences 1912-1917, (3) eruptive episodes and seismicity, (4) general characters of local earthquakes, (5) comparison with lava fluctuation, (6) suggested relations Mauna Loa and Kilauea, (7) frequency related to equinox, (8) earthquake agreement instantaneous, tilt not, (9) tremors: two kinds present, (10) harmonic slower tremors; comparison Japan, (11) spasmodic quicker tremors; comparison Japan, (12) strong tremors accompanying eruption, (13) ordinary spasmodic tremor; general character, (14) ordinary harmonic tremor; its direction, (15) quantitative comparison tilt and tremors, methods of tremor measurement, (16) table of comparative tilt and tremors, (17) chart showing accordances, (18) accordance tilt and tremor, discordance earthquake frequency, (19) amplitude as expressing energy, (20) earthquake frequency accordant with rate of lava movement 1917-1918. Chapter 7 summarizes results of the investigation.

Earthquake sequences and b values in the southeast United States

1974 ◽  
Vol 64 (1) ◽  
pp. 267-273
Author(s):  
Leland Timothy Long
Keyword(s):  
United States ◽  
South Carolina ◽  
B Value ◽  
Earthquake Activity ◽  
Southeast United States ◽  
B Values ◽  
History Of ◽  
Earthquake Sequences ◽  
Foreshock Activity ◽  
Epicentral Region

abstract Aftershock and foreshock activity within 12 hr of the July 13, 1971 earthquake near Seneca, South Carolina, indicates a b value of 0.9 at ML = 3.0. Approximately 40 events recorded in a 5-day aftershock survey near Seneca indicate a b value of 1.7 at ML = 0.5. A sequence of over 40 events occurring west of McCormick, South Carolina, indicates a b value of 1.3 at ML = 2.4. The McCormick sequence was active for 4 months. Unlike the Seneca region, the McCormick region has a history of earthquake activity. Examinations of other published southeastern b values suggest that southeastern United States earthquakes originate from conditions of ambient stress which vary with epicentral region or magnitude.

Eleven million years of arc volcanism at the Aucanquilcha Volcanic Cluster, northern Chilean Andes: implications for the life span and emplacement of plutons

2006 ◽  
Vol 97 (4) ◽  
pp. 415-436 ◽  
Author(s):  
Anita L. Grunder ◽  
Erik W. Klemetti ◽  
Todd C. Feeley ◽  
Claire M. McKee
Keyword(s):  
Volcanic System ◽  
Arc Volcanism ◽  
Pyroxene Andesite ◽  
Stage 4 ◽  
Third Stage ◽  
Incremental Growth ◽  
History Of ◽  
Intrusive Suite ◽  
Continental Magmatism ◽  
Active Composite

ABSTRACTThe arid climate of the Altiplano has preserved a volcanic history of ∼11 million years at the Aucanquilcha Volcanic Cluster (AVC), northern Chile, which is built on thick continental crust. The AVC has a systematic temporal, spatial, compositional and mineralogical development shared by other long-lived volcanic complexes, indicating a common pattern in continental magmatism with implications for the development of underlying plutonic complexes, that in turn create batholiths.The AVC is a ∼700-km2, Tertiary to Recent cluster of at least 19 volcanoes that have erupted andesite and dacite lavas (∼55 to 68 wt.% SiO2) and a small ash-flow tuff, totalling 327 ± 20 km3. Forty 40Ar/39Ar ages for the AVC range from 10·97 ± 0·35 to 0·24 ± 0·05 Ma and define three major 1·5 to 3 million-year pulses of volcanism followed by the present pulse expressed as Volcán Aucanquilcha. The first stage of activity (∼11–8 Ma, Alconcha Group) produced seven volcanoes and the 2-km3 Ujina ignimbrite and is a crudely bimodal suite of pyroxene andesite and dacite. After a possible two million year hiatus, the second stage of volcanism (∼6–4 Ma, Gordo Group) produced at least five volcanoes ranging from pyroxene andesite to dacite. The third stage (∼4–2 Ma, Polan Group) represents a voluminous pulse of activity, with eruption of at least another five volcanoes, broadly distributed in the centre of the AVC, and composed dominantly of biotite amphibole dacite; andesites at this stage occur as magmatic inclusions. The most recent activity (1 Ma to recent) is in the centre of the AVC at Volcán Aucanquilcha, a potentially active composite volcano made of biotite-amphibole dacite with andesite and dacite magmatic inclusions.These successive eruptive groups describe (1) a spatial pattern of volcanism from peripheral to central, (2) a corresponding change from compositionally diverse andesite-dacite volcanism to compositionally increasingly restricted and increasingly silicic dacite, (3) a change from early anhydrous mafic silicate assemblages (pyroxene dominant) to later biotite amphibole dacite, (4) an abrupt increase in eruption rate; and (5) the onset of pervasive hydrothermal alteration.The evolutionary succession of the 327-km3 AVC is similar to other long-lived intermediate volcanic complexes of very different volumes, e.g., eastern Nevada (thousands of km3, Gans et al. 1989; Grunder 1995), Yanacocha, Perú (tens of km3, Longo 2005), and the San Juan Volcanic System (tens of thousands of km3, Lipman 2007) and finds an analogue in the 10-m. y. history and incremental growth of the Cretaceous Tuolumne Intrusive Suite (Coleman et al. 2004; Glazner et al. 2004). The present authors interpret the AVC to reflect episodic sampling of the protracted and fitful development of an integrated and silicic middle to upper crustal magma reservoir over a period of at least 11 million years.

scholarly journals Caldera’s Breathing: Poroelastic Ground Deformation at Campi Flegrei (Italy)

2021 ◽  
Vol 9 ◽  
Author(s):  
Micol Todesco
Keyword(s):  
Pore Pressure ◽  
Ground Deformation ◽  
Campi Flegrei ◽  
Driving Mechanism ◽  
Extensive Literature ◽  
Magma Intrusion ◽  
Volcanic System ◽  
Scientific Debate ◽  
Fluid Content ◽  
History Of

Ground deformation at Campi Flegrei has fuelled a long-term scientific debate about its driving mechanism and its significance in hazard assessment. In an active volcanic system hosting a wide hydrothermal circulation, both magmatic and hydrothermal fluids could be responsible, to variable degrees, for the observed ground displacement. Fast and large uplifts are commonly interpreted in terms of pressure or volume changes associated with magma intrusion, while minor, slower displacement can be related to shallower sources. This work focuses on the deformation history of the last 35 years and shows that ground deformation measured at Campi Flegrei since 1985 is consistent with a poroelastic response of a shallow hydrothermal system to changes in pore pressure and fluid content. The extensive literature available for Campi Flegrei allows constraining system geometry, properties, and conditions. Changes in pore pressure and fluid content necessary to cause the observed deformation can then be calculated based on the linear theory of poroelasticity. The predicted pore pressure evolution and fluid fluxes are plausible and consistent with available measurements and independent estimates.

Explanation

2018 ◽  
Author(s):  
Philip Kitcher
Keyword(s):  
Scientific Explanation ◽  
Logical Empiricism ◽  
General Character ◽  
Philosophical Debate ◽  
Law Of Nature ◽  
History Of ◽  
Covering Law ◽  
1960S And 1970S ◽  
The 1960S ◽  
Functional Explanations

Philosophical reflections about explanation are common in the history of philosophy, and important proposals were made by Aristotle, Hume, Kant and Mill. But the subject came of age in the twentieth century with the provision of detailed models of scientific explanation, prominently the covering-law model, which takes explanations to be arguments in which a law of nature plays an essential role among the premises. In the heyday of logical empiricism, philosophers achieved a consensus on the covering law model, but, during the 1960s and 1970s, that consensus was challenged through the recognition of four major kinds of difficulty: first, a problem about the relation between idealized arguments and the actual practice of explaining; second, the difficulty of characterizing the underlying notion of a law of nature; third, troubles in accounting for the asymmetries of explanation; and, four, recalcitrant problems in treating statistical explanations. Appreciation of these difficulties has led to the widespread abandonment of the covering-law model, and currently there is no consensus on how to understand explanation. The main contemporary view seeks to characterize explanation in terms of causation, that is, explanations are accounts that trace the causes of the events (states, conditions) explained. Other philosophers believe that there is no general account of explanation, and offer pragmatic theories. A third option sees explanation as consisting in the unification of the phenomena. All of these approaches have associated successes, and face particular anomalies. Although the general character of explanation is now a subject for philosophical debate, some particular kinds of explanation seem to be relatively well understood. In particular, functional explanations in biology, which logical empiricists found puzzling, now appear to be treated quite naturally by supposing them to make tacit reference to natural selection.

Melting the roof of a chamber containing a hot, turbulently convecting fluid

1988 ◽  
Vol 188 ◽  
pp. 107-131 ◽  
Author(s):  
Herbert E. Huppert ◽  
R. Stephen J. Sparks
Keyword(s):  
Salt Solution ◽  
Thermal History ◽  
Convective Motion ◽  
Basaltic Rock ◽  
Aqueous Salt Solution ◽  
Volcanic System ◽  
Northwestern Argentina ◽  
History Of ◽  
Basaltic Layer ◽  
Surrounding Fluid

The input of a hot, turbulently convecting fluid to fill a chamber can result in the roof of the chamber melting. The rate of melting of the roof is here analysed experimentally and theoretically. Three separate cases are considered. The melt may be heavier than the fluid and initially sink through it. The intense motion in the fluid then mixes the falling melt in with it. Alternatively, the melt may be less dense than the fluid and form a separate layer between the roof and the fluid. This melt layer can itself be in quite vigorous convective motion. An intermediate case is shown to be possible, wherein the melt is initially denser than the fluid, and sinks. As its temperature increases and its density decreases, it becomes less dense than the surrounding fluid and rises. Experimental simulations of each of these three cases are described. The experiments employ a roof of either wax or ice which is melted by the aqueous salt solution beneath it. The second case, that of a light melt, has important geological applications. It describes the melting of the continental crust by the emplacement of a hot, relatively dense input of fluid basaltic rock. Both the basaltic layer and the resultant granitic melt layer crystallize and increase their viscosities as they cool. These effects are incorporated into the analysis and the rate of melting and the temperatures of the two layers are calculated as functions of time. The process is exemplified by the formation of the Cerro Galan volcanic system in Northwestern Argentina over the last 5 million years. An Appendix analyses the thermal history of the fluid in a chamber that does not melt and compares the results obtained with those derived previously.

I. Preliminary report to the hydrographer of the admiralty on some of the results of the cruise of H. M. S. 'Challenger' between Hawaii and Valparaiso

1876 ◽  
Vol 24 (164-170) ◽  
pp. 463-470 ◽  
Keyword(s):  
Preliminary Report ◽  
Volcanic Ash ◽  
Summit Crater ◽  
Lava Flows ◽  
Mauna Loa ◽  
Temperature Observations ◽  
Lava Lakes ◽  
Warm Clothing ◽  
The Way

Sir,—I have the honour to report that we left Honolulu on the 11th of August, and on the 12th we sounded in 2050 fathoms, and took a series of temperature observations between the islands of Oahu and Hawaii. At night a crimson reflection was visible in the position of the top of Mauna Loa; but as we understood that the side crater of Kilauea only was in eruption, we supposed that that was some great conflagration of forest on the flank of the mountain. All the following day we steamed against a head wind along the rugged and picturesque coast of Hawaii—headlands of lava and volcanic ash separated by deep wooded ravines or “gulches,” with a rapid hill-stream running in the bottom of each. The top of Mauna Loa was covered with clouds during the day; but at night a splendid crimson glare hung over the mountain, and lit up the clouds to a wide radius, and it became evident that we were fortunate enough, to see one of the rare eruptions of the summit crater. Early on Saturday we cast anchor in Hilo Bay; and a party of us made arrangements to start as early as possible for the volcano of Kilauea thirty miles distant, intending, if the eruption of the summit crater continued and if we found it practicable, to push on to the top of the mountain. We left Hilo in the afternoon, taking magnetic and photographic instruments with us, and rode all night through the forest and over the lava-flows, reaching the rest-house at the side of the crater of Kilauea early in the morning. During the early part of the night the light from the summit crater was very brilliant, but it began to pale soon after midnight; and when we arrived at Kilauea we found that the column of smoke at the top of the mountain had almost entirely disappeared, and that the eruption was virtually over. This was no great disappointment to us; for we had learned that the ascent of the upper peak could not be undertaken with reasonable safety without much greater preparation in the way of provisions and warm clothing than we had had time to make, and we should have been obliged to give up the idea in any case. In the afternoon we went down into the crater and walked for about three miles over the nearly level lava of the eruption of 1868; we then clambered up to the ridge overlooking the two liquid lava-lakes, which have remained nearly in the same condition since 1868. We were greatly struck with the fluidity of the melted lava, which washed about in the basins with very much the appearance and sound of water. The night was perfectly still; and it had a most singular effect to see the two glowing lakes tossing like the sea in a storm, and a red surf dashing against the encircling rocks and springing forty or fifty feet into the air in wreaths of fiery spray. Lieutenant Bromley and I recrossed the lava-bed after nightfall, and our guide missed the ordinary path. In several places on either side of us the surface of the lava was glowing of a dull red, and we could see through the cracks the crust red-hot a couple of inches under our feet, and the liquid lava flowing beneath at the depth of about half a yard. Observations were made by Lieutenant Bromley in the crater and on its rim with the “Fox” dip-circle for inclination and intensity, and with the prismatic compass for declination. Several excellent photographs of the crater were taken during the day. We returned to the ship on the evening of the 16th, and on the 19th we left Hilo and proceeded under sail for Tahiti, 2270 miles distant.

scholarly journals Excavations in Melos, 1899: C. The Pottery

1899 ◽  
Vol 5 ◽  
pp. 14-19
Author(s):  
C.C. Edgar
Keyword(s):  
Short Description ◽  
General Character ◽  
Chronological Order ◽  
Proper Place ◽  
British School ◽  
History Of ◽  
Preceding Season ◽  
Rough Calculation

In a report which appeared in the last number of the British School Annual I gave a short description, in chronological order, of the main classes of pottery found at Phylakopi, and tried to indicate their place in the history of Aegean art. I shall not attempt in the present paper to write a fuller and more accurate account on the same lines. The proper place for that will be in the final publication. All I propose to do now is to make a few desultory notes of a general character on the finds of this last season.The supply of pottery was as abundant this year as ever. To give an idea of how closely the soil is packed with it, I find on a rough calculation that an average day's work yielded somewhere between ten thousand and twenty thousand fragments. The experience gained in the preceding season made this large daily harvest much more easy to deal with.

scholarly journals Los ayuntamientos y la educación primaria durante la Segunda República

2018 ◽  
Vol 29 ◽  
pp. 141
Author(s):  
Héctor Vicente Sánchez
Keyword(s):  
Religious Education ◽  
Primary Education ◽  
Fine Arts ◽  
General Character ◽  
New Schools ◽  
Start Up ◽  
History Of ◽  
Politica Educativa ◽  
Public Instruction ◽  
Educación Primaria

Resumen: Cuando los dirigentes republicanos accedieron al po­der uno de sus principales objetivos fue llevar a cabo una profunda reforma en la educación. El desarrollo de la política educativa republicana tuvo su reflejo en una amplia producción historiográfica posterior. Fueron algunos de los propios ejecutores de la refor­ma los que primeramente plasmaron por escrito su labor al frente del Ministerio de Instrucción Pública y Bellas Artes. Estos fueron los casos de Rodolfo Llopis y Marcelino Domingo. Tras estos primeros estudios habría que esperar a la caída de la Dictadura para que volviera a escribirse sobre la educación republicana. Las primeras investigaciones tuvieron un carácter general, transcurriendo algún tiempo hasta que co­menzaron a realizarse estudios centrados en localida­des concretas. El presente trabajo tiene como objetivo analizar la labor de los Ayuntamientos con respecto a la educación primaria durante el quinquenio republi­cano. Serán tres los ámbitos en los que centraremos nuestra atención: la puesta en funcionamiento de nuevos centros escolares, la sustitución de la ense­ñanza religiosa y la puesta en funcionamiento de las instituciones circumescolares.Palabras clave: Segunda República, Educación primaria, Ayuntamiento, colegios, laicismo, instituciones circumescolares.Abstract: When the Republican leaders acceded to power, one of their main objectives was a deep reform in education. The development of the Repub­lican educational policy is reflected in a sub­sequent, extensive historiographical corpus. It was in fact the same architects of the reform who first recorded this whilst at the head of the Ministry of Public Instruction and Fine Arts, namely, Rodolfo Llopis and Marcelino Domin­go. Following these first studies, we had to wait for the fall of the dictatorship for the history of republican educational reform to be continued. The first such research efforts were of a general character, and some time passed until it began to focus on specific localities. This paper aims to analyse the work of the local authorities with respect to primary education during the repub­lican period. Three areas will be central to this: the start-up of new schools, the substitution of religious education and the start-up of the extra-scholarly institutions.Key words: Second Republic, Primary Education, local authority, colleges, secularism, extra-scholarly institutions.

scholarly journals THE MAIN STAGES IN THE DEVELOPMENT OF PROSECUTION AUTHORITIES OF THE CHUVASH REPUBLIC IN THE MODERN PERIOD

2021 ◽  
pp. 78-86
Author(s):  
Rustem A. Idrisov
Keyword(s):  
100Th Anniversary ◽  
Practical Significance ◽  
General Character ◽  
Modern History ◽  
Political Processes ◽  
Modern Period ◽  
History Of ◽  
Chuvash Republic ◽  
The Republic ◽  
The Individual

The article is the first attempt to periodize the history of the modern activities performed by the prosecution authorities of the Chuvash Republic. The methodological basis for singling out the individual stages of this process is its study in the context of macrosocial processes. The use of this approach enables to carry out an interdisciplinary study of individual facts and events in the modern history of the Prosecutor’s Office of Chuvashia. In this case, it is possible to analyze them in conjunction with the general trends in the development of the state and the law of the country in the period under review, the personal contribution of the heads and employees of the prosecutor’s office, and the social changes that took place in society. The novelty of the study is that the proposed periodization in the modern history of the prosecution authorities of Chuvashia is carried out for the first time. In addition, the use of macrosocial processes context in historical research is also new; it has made it possible to use statutory instruments more widely as sources. Without their consideration, periodization of the activities carried out by law enforcement agencies, which include the Prosecutor’s Office, will not be sufficiently justified. The results of the study consist in separating three main stages in the activity of the Chuvash Republic prosecution authorities in the modern period: 1) 1991–1999; 2) 2000–2009; 3) 2010–2020. All of them have distinctive features that have become the basis for this separation. These features reflect both global social and political processes that took place in the country in these three decades, and particular regional changes that took place in the life of the republic. This interrelation is also a consequence of the very status of the prosecution authorities, which, on the one hand, have the character of federal authorities, and on the other hand, directly influence and are influenced by regional development processes. The most illustrative features characterizing the stages in the modern history of Chuvashia’s prosecution authorities are considered in the text of the article, which sets out the author’s conclusions. The conducted research has a high degree of practical significance and prospects for continuing this work. The author is a member of the research group analyzing the history of the Chuvash Republic prosecution authorities in connection with celebrating their 100th anniversary. Therefore, a number of conclusions proposed in this article have the general character of methodological recommendations aimed at preparing a general monographic publication on the topic of the study.

scholarly journals Art. II.—Essays on the Puránas. I.

1838 ◽  
Vol 5 (9) ◽  
pp. 61-72
Author(s):  
Horace Hayman Wilson
Keyword(s):  
Social System ◽  
General Character ◽  
European Public ◽  
History Of ◽  
The Creation ◽  
Similar Class ◽  
Definition Of ◽  
The Universe

The earliest inquiries into the religion, chronology, and history of the Hindús, ascertained that there existed a body of writings especially devoted to those subjects, from which it was sanguinely anticipated much valuable and authentic information would be derived. These were the Puránas of Sanscrit literature, collections which, according to the definition of a Purána agreeably to Sanscrit writers, should treat of the creation and renovation of the universe, the division of time, the institutes of law and religion, the genealogiès of the patriarchal families, and the dynasties of kings; and they, therefore, offered a prospect of our penetrating the obscurity in which the origin and progress of the Hindú social system had so long been enveloped. A formidable difficulty, however, presented itself in the outset, arising from the voluminous extent of this branch of the literature of the Hindús, and the absence of all facilities for acquiring a knowledge of its nature. The Puránas are eighteen in number, besides several works of a similar class, called Upa, or minor, Puránas. The former alone comprehend, it is asserted, and the assertion is not very far from the truth, four hundred thousand slokas, or sixteen hundred thousand lines, a quantity which any individual European scholar could scarcely expect to peruse with care and attention, unless his whole time were devoted exclusively for very many years, to the task. Nor was any plan, short of the perusal of the whole, likely to furnish satisfactory means of judging of their general character: few of them are furnished with anything in the shape of an index, or summary of contents, and none of them conform to any given arrangement; so that to know with accuracy what any one contains, it is necessary to read the entire work. The immensity of the labour seems to have deterred Sanscrit students from effecting even what was feasible, the publication or translation of one or two of the principal Puránas, and to the present day not one of them is accessible to the European public.

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