III. An account of the great earthquake experienced in Chile on the 20th of February, 1835; with a map

1836 ◽  
Vol 126 ◽  
pp. 21-26 ◽  
Keyword(s):  
Royal Society ◽  
Earth’S Crust ◽  
Great Earthquake ◽  
Sea Birds ◽  
The Earth ◽  
Great Confidence ◽  
Earth's Crust ◽  
The Moment

The phenomena attending this great disturbance of the surface of the earth have been so varied, and the extent of its effects so considerable, that I should almost deviate from my duty if I did not endeavour to draw up and transmit to the Royal Society some account of a convulsion which has laid in ruins three provinces, and caused incalculable damage to the southern part of this country. I am the more inclined to take this step from a happy concurrence of circumstances having drawn several scientific observers to Concepcion shortly after the catastrophe, who have obligingly confided their notes to me. I trust therefore the Royal Society will not consider that I am about to trespass upon its time. An idea, in some degree fanciful, prevailed for some time after the conquest of these countries by the Spaniards, that these convulsions of the earth’s crust occurred at intervals of a century; afterwards it was supposed that about fifty years was the term which usually elapsed between great shocks; but, since the commencement of this century, the repeated catastrophes which have occurred, especially in the years 1812 in Caraccas, 1818 in Copiapo, 1822 in the province of Santiago, 1827 in Bogota, 1828 in Lima, 1829 in Santiago, and 1832 in Huasco, have prepared the minds of the inhabitants to expect at all times these frightful oscillations of the earth, which, although they cause little sensation at first, after some time affect the nerves in a manner not easy to account for by ordinary causes. That they happen at all times and in all states of the atmosphere seems clearly decided. The finest weather, and the most variable, equally prevail at the moment; but many are the fancied signs by which the coming earthquakes are predicted, and in the faith of which the inhabitants confide, as they think their experience bears them out. While some place great confidence in rats running violently over the ceilings of the room, others prepare for a shock when they observe the stars twinkling more than usual, and all fears are removed when much lightning coruscates in the Cordillera. As far as my own observations go, little reliance can be placed on the two former prognostics; something more certain seems to be due to the latter. A few hours previous to the earthquake which I am about to describe, immense flocks of sea birds proceeded from the coast towards the Cordillera, a circumstance which occurred prior to the great shock of 1822; and it is affirmed by too many respectable persons not to be entitled to some degree of credit, that on the morning of the convulsion all the dogs disappeared from Talcahuano.

On the degree of uncertainty which local attraction, if not allowed for, occasions in the map of a country, and in the mean figure of the earth as determined by geodesy ; a method of obtaining the mean figure free from ambiguity by a comparison of the Anglo-Gallic, Russian, and Indian Arcs ; and speculations on the constitution of the earth's crust

1864 ◽  
Vol 13 ◽  
pp. 253-276 ◽  
Keyword(s):  
Royal Society ◽  
Earth’S Crust ◽  
Plumb Line ◽  
Remarkable Difference ◽  
Astronomical Society ◽  
Royal Astronomical Society ◽  
The Earth ◽  
Figure Of The Earth ◽  
The Mean ◽  
Earth's Crust

1. In former communications to the Royal Society I have shown that Local Attraction, owing to the amount it in some places attains, is a more troublesome element to deal with in geodetical operations than had generally been supposed. The Mountains and the Ocean were shown to combine to make the deviation of the plumb-line as much as 22".71, 17".23, 21".05, 34".16 (or quantities not differing materially from them) in the four principal stations of the Great Arc of India between Cape Comorin and the Himmalayas—viz. at Punnœ (8° 9' 31"), Damargida (18° 3' 15'), Kalianpur (24° 7' 11"), Kaliana (29° 30' 48") ; and how much these might be increased or lessened by the effect of variations of density in the crust below t was difficult to say. Deviations amounting to at least such quantities as 7''.61 and 7".87 were shown to exist in the stations of the Indian Arc, arising from this last cause (see Phil. Trans. 1861, p. 593 (4) and (5)). M. Otto Struve has lately called attention to similarly important deflections caused by local attraction in Russia—and especially to a remarkable difference of deflection at two stations near Moscow, only about eighteen miles apart, amounting to as much as 18", which is attributed to an invisible unknown cause in the strata below (see Monthly Notices of the Royal Astronomical Society, April 1862).

scholarly journals INQUIRY INTO VERTICAL MOVEMENTS OF THE EARTH‘S CRUST BASED ON SAMPLES FROM EASTERN LITHUANIA

2014 ◽  
Vol 40 (2) ◽  
pp. 58-67
Author(s):  
Ruta Puziene ◽  
Asta Anikeniene ◽  
Gitana Karsokiene
Keyword(s):  
Regression Models ◽  
Earth’S Crust ◽  
Movement Velocity ◽  
Correlation Matrices ◽  
Vertical Movements ◽  
Statistical Correlations ◽  
Horizontal Gradients ◽  
The Earth ◽  
Earth's Crust ◽  
Made In

In the research of vertical movements of the earth’s crust, examination of statistical correlations between the measured vertical movements of the earth’s crust and territorial geo-indexes is accomplished with the help of mathematical statistical analysis. Availability of the precise repeated levelling measuring data coupled with the preferred research methodology offer a chance to determine and predict recent vertical movements of the earth’s crust. For the inquiry into recent vertical movements of the earth’s crust, a Lithuanian class I vertical network levelling polygon was used. Drawing on measurements made in the polygon, vertical velocities of earth’s crust movements were calculated along the following levelling lines. For determining the relations shared by vertical movements of the earth’s crust and territorial geo-parameters, the following territory-defining parameters are accepted. Examination of the special qualities of relations shared by vertical movements of the earth’s crust and geo-parameters in the territory under research contributed to the computation of correlation matrices. Regression models are worked out taking into consideration only particular territory-defining geo-parameters, i.e. only those parameters which exhibit the following correlation coefficient value of the vertical earth’s crust movement velocity: r ≥ 0.50. A forecast of the velocities pertaining to vertical movements of the earth’s crust in the territory under examination was made with the application of regression models. Further in the process of this research, a map was compiled specifying the velocities of vertical movements of the earth’s crust in the territory. In the eastern part of this territory, the earth’s crust rises at a rate of up to 3 mm/year; while in the western part of it, the earth crust lowers at a rate of up to –1.5 mm/year. In order to pinpoint territories characterised by temperate and regular rising/lowering or intensive rising/lowering, a map of horizontal gradients of recent vertical earth crust movements in the territory enclosed by levelling polygon was compiled.

How I Learned to Stop Worrying and Love the TermAnthropocene

2014 ◽  
Vol 1 (2) ◽  
pp. 257-264 ◽  
Author(s):  
Timothy Morton
Keyword(s):  
Eighteenth Century ◽  
Royal Society ◽  
Earth’S Crust ◽  
Steam Engine ◽  
Radioactive Materials ◽  
Earth Systems ◽  
Huge Data ◽  
Earth's Crust ◽  
Great Acceleration ◽  
Geological Period

Not a day goes by in the 2010s without some humanities scholars becoming quite exercised about the termAnthropocene. In case we need reminding,Anthropocenenames the geological period starting in the later eighteenth century when, after the invention of the steam engine, humans began to deposit layers of carbon in Earth’s crust. Paul Crutzen and Eugene Stoermer’s term has been current since 2000.1In 1945, there occurred “The Great Acceleration,” a huge data spike in the graph of human involvement in Earth systems. (The title’s Kubrick joke stems from the crustal deposition of radioactive materials since 1945.) Like Marx, Crutzen sees the steam engine as iconic. As this is written, geologists such as Jan Zalasiewicz are convincing the Royal Society of Geologists to make the term official.

scholarly journals Improving of electrical channels for magnetotelluric sounding instrumentation

2015 ◽  
Vol 4 (2) ◽  
pp. 149-154 ◽  
Author(s):  
A. M. Prystai ◽  
V. O. Pronenko
Keyword(s):  
Electric Field ◽  
Electric Fields ◽  
Deep Structure ◽  
Experimental Tests ◽  
Magnetotelluric Sounding ◽  
Earth’S Crust ◽  
Geomagnetic Variations ◽  
The Earth ◽  
Wide Range ◽  
Earth's Crust

Abstract. The study of the deep structure of the Earth's crust is of great interest for both applied (e.g. mineral exploration) and scientific research. For this the electromagnetic (EM) studies which enable one to construct the distribution of electrical conductivity in the Earth's crust are of great use. The most common method of EM exploration is magnetotelluric sounding (MT). This passive method of research uses a wide range of natural geomagnetic variations as a powerful source of electromagnetic induction in the Earth, producing telluric current variations there. It includes the measurements of variations of natural electric and magnetic fields in orthogonal directions at the surface of the Earth. By this, the measurements of electric fields are much more complicated metrological processes, and, namely, they limit the precision of MT prospecting. This is especially complicated at deep sounding when measurements of long periods are of interest. The increase in the accuracy of the electric field measurement can significantly improve the quality of MT data. Because of this, the development of a new version of an instrument for the measurements of electric fields at MT – both electric field sensors and the electrometer – with higher levels relative to the known instrument parameter level – was initiated. The paper deals with the peculiarities of this development and the results of experimental tests of the new sensors and electrometers included as a unit in the long-period magnetotelluric station LEMI-420 are given.

Metamorphic Rocks

2018 ◽  
Author(s):  
Alex Maltman
Keyword(s):  
Metamorphic Rock ◽  
Central Area ◽  
Tectonic Stress ◽  
Earth’S Crust ◽  
Metamorphic Rocks ◽  
Tectonic Plates ◽  
The Earth ◽  
Two Factors ◽  
Earth's Crust ◽  
Increased Pressure

We come now to the metamorphic rocks, the result of modifications to already existing rock. I’m well aware that this can all seem a bit mysterious. After all, no one has ever seen the changes take place; no one has ever witnessed a metamorphic rock form—the processes are imperceptibly slow, and they happen deep in the Earth’s crust, way out of sight. Why should these changes happen? Well, they are primarily driven by increases in pressure and temperature, so we begin with a look at these two factors. There are sites in the Earth’s crust where material becomes progressively buried. It happens, for example, where a tectonic plate is driving underneath another one, taking rocks ever deeper as it descends. It can happen in the central area of a plate that is stretching and sagging, allowing thick accumulations of sediment. It’s pretty self-evident that as buried material gets deeper, because of the growing weight of rocks above bearing down due to gravity, it becomes subjected to increasing burial pressure. Less intuitive, though, is the fact that this pressure acts on a volume of rock equally in all directions. Imagine a small volume of rock at depth. It’s bearing the weight of the rocks above it, and so it responds by trying to move downward and to spread out laterally. Of course, it can’t because it’s constrained all around by other volumes of rock that are trying to do exactly the same thing. And so the downward gravity is translated into an all-around pressure. It’s the same effect as diving down to the bottom of a swimming pool. You feel the increased pressure owing to the weight of water above, but you feel it equally in all directions. All-round pressure like this can cause things to change in volume, through changing their density, but it can’t change their shape. However, there can be another kind of pressure as well, and this does have direction, and it can cause change of shape. In the Earth, we call it tectonic stress. It comes about through heat-driven motions in the Earth, including the movement of tectonic plates.

scholarly journals Critically Stressed Areas of Earth’s Crust as Medium for Man-caused Hazards

2018 ◽  
Vol 56 ◽  
pp. 02007 ◽  
Author(s):  
Andrian Batugin
Keyword(s):  
Critical Stress ◽  
Earth’S Crust ◽  
Mining Operations ◽  
Induced Earthquake ◽  
The Earth ◽  
Stress Zone ◽  
Mining Works ◽  
Earth's Crust ◽  
Rock Strata ◽  
Insight Into

Despite advances in rockburst studies, suddenness of major geodynamic events is reported in a number of cases. Phenomenological tectonophysical model is suggested to explain some geodynamics phenomena. Prof. Petukhov I.M. suggested a concept: the Earth crust's critical stress condition is developed due to horizontal compressive forces and entrains rock strata from the sub-surface to a certain depth. The conditions that induced earthquake in 2013 at Bachat coal field in south west Kuzbass are considered in terms of critical stress developed in the top layer of the Earth crust. Estimates show that the size of the critical stress zone, produced presumably by interaction of huge (over 100 km) crustal blocks is at least 10km. Whereas critical stress zone is located in the top part of Earth's crust, mining operations in the pit including blast operations was making a direct impact on this area. Shallow occurrence of critical stress area and its size can provide insight into why mining works brought about induced earthquake with hypocenter at the depth of several kilometers. The conclusion has been made that regional areas of critical stress within rock massif developed as a result of crustal blocks interaction create hazard medium for mining.

scholarly journals Accelerated non-linear destruction of the earth's crust

2001 ◽  
Vol 6 (4) ◽  
pp. 281-290
Author(s):  
E. V. Artyushkov
Keyword(s):  
Lower Crust ◽  
Sedimentary Basins ◽  
Earth’S Crust ◽  
Mountain Ranges ◽  
Crustal Rocks ◽  
The Earth ◽  
Lithospheric Plates ◽  
Temperature And Pressure ◽  
Earth's Crust ◽  
Major Hydrocarbon

The upper part of the Earth—the lithospheric layer,∼100 km thick, is rigid. Segments of this spherical shell–lithospheric plates are drifting over a ductile asthenosphere. On the continents, the lithosphere includes the Earth's crust,∼40 km thick, which is underlain by peridotitic rocks of the mantle. In most areas, at depths∼20–40 km the continental crust is composed of basalts with density∼2900kg m−3. At temperature and pressure typical for this depth, basalts are metastable and should transform into another assemblage of minerals which corresponds to garnet granulites and eclogites with higher densities 3300–3600 kgm−3. The rate of this transformation is extremely low in dry rocks, and the associated contraction of basalts evolves during the time≥108a. To restore the Archimede's equilibrium, the crust subsides with a formation of sedimentary basins, up to 10–15 km deep.Volumes of hot mantle with a water-containing fluid emerge sometimes from a deep mantle to the base of the lithosphere. Fluids infiltrate into the crust through the mantle part of the lithosphere. They catalyze the reaction in the lower crust which results in rock contraction with a formation of deep water basins at the surface during∼106a. The major hydrocarbon basins of the world were formed in this way. Infiltration of fluids strongly reduces the viscosity of the lithosphere, which is evidenced by narrow-wavelength deformations of this layer. At times of softening of the mantle part of the lithosphere, it becomes convectively replaced by a hotter and lighter asthenosphere. This process has resulted in the formation of many mountain ranges and high plateaus during the last several millions of years. Softening of the whole lithospheric layer which is rigid under normal conditions allows its strong compressive and tensile deformations. At the epochs of compression, a large portion of dense eclogites that were formed from basalts in the lower crust sink deeply into the mantle. In some cases they carry down lighter blocks of granites and sedimentary rocks of the upper crust which delaminate from eclogitic blocks and emerge back to the crust. Such blocks of upper crustal rocks include diamonds and other minerals which were formed at a depth of 100–150 km.

I.—Contributions to the Study of Volcanos.—Second Series

1876 ◽  
Vol 3 (8) ◽  
pp. 337-345 ◽  
Author(s):  
John W. Judd
Keyword(s):  
Earth’S Crust ◽  
Abnormal Development ◽  
Preliminary Stage ◽  
Mountain Ranges ◽  
Sedimentary Deposits ◽  
The Earth ◽  
Mountain System ◽  
Earth's Crust ◽  
Green Mountains

The study of the great mountain ranges of America by Rogers, Hall, Dana, Le Conte, Hunt, and other geologists, has now thrown much new light on the earth-movements which precede and accompany the formation of mountain chains. As the result of these researches, it appears certain that the preliminary stage in the formation of every mountain system has consisted in a long-continued depression of the area which is afterwards to become its site; and, in consequence of this prolonged subsidence, the accumulation of an enormous thickness of stratified rocks, within the great trough so formed, has taken place. Of this character, as is now well known, have been the earlier manifestations of the subterranean forces that were concerned in the formation of the Appalachians, Green Mountains, and other American ranges; the districts in which they are situated were subjected to long-continued depression, which permitted of an abnormal development of all the members of the sedimentary deposits formed during this initiatory period; and it was by the folding, metamorphism and crushing together of this abnormally thickened portion of the earth's crust that the indurated and elevated masses have been formed which denudation has sculptured into the existing mountain chains.

scholarly journals ZONES OF RECENT ACTIVATION AND SCHEME OF THE EARTH CRUST PERMEABILITY OF UKRAINE

2021 ◽  
Vol 17 (1) ◽  
pp. 75-84
Author(s):  
V.V. Gordienko ◽  
L.Ya. Gordienko ◽  
J.A. Goncharova ◽  
V.M. Tarasov
Keyword(s):  
Surface Waters ◽  
Previous Analysis ◽  
Relevant Information ◽  
Earth’S Crust ◽  
Near Surface ◽  
The Past ◽  
The Earth ◽  
Continue Research ◽  
Earth's Crust ◽  
Background Gas

An attempt is considered to supplement the criteria for identifying zones of recent activation in the territory of Ukraine with another one — data on the results of studies of helium concentration in ground-water. The previous analysis of information showed that as regional criteria, information can be applied on anomalies in heat flow, increased electrical conductivity of Earth’s crustal and the upper mantle rocks, distribution of mantle gravitational anomalies, and surface uplifts over the past millions of years. They were chosen among others precisely because of the dissemination of relevant information throughout the country. This requirement is also met by the permeability Scheme of the earth’s crust of Ukraine, which is a fragment of the permeability Scheme of the earth’s crust of the European part of the USSR based on the results of helium studies. The principal applicability of such information for solving the problem is shown. Areas of maximum helium concentrations in near-surface waters are indicated, primarily those associated with disjunctive dislocation. Theу are concentrated in the south-west of Ukraine and in Moldova. The disadvantages of the Scheme are noted, due to poor study and significant variations in background gas concentrations, directly caused not by recent activation, but by the peculiarities of helium generation by rocks of the upper part of the earth’s crust. There are inconsistencies between the previously obtained ideas about the activated zones and the data of the Scheme. They are especially large in the Carpathian, Crimean and Donetsk regions, and are noticeable in others. Therefore, it seems necessary, first, to continue research, thicken the network of observations and develop a methodology for analyzing their results.

scholarly journals An investigation of the movement of water and petroleum through rock under high pressure

1917 ◽  
Author(s):  
◽  
Ward Wesley Kelley
Keyword(s):  
High Pressure ◽  
Water Supply ◽  
Underground Water ◽  
Ore Deposits ◽  
Earth’S Crust ◽  
The Earth ◽  
Earth's Crust

... Then working upon the problems of underground water supply, ore deposits, and petroleum accumulations, the lack of definite informatlon regarding the laws which govern the movement of liquids through the rocks making up the earth's crust is a great stumbling block to investigation. In the fall of 1916 the writer undertook to study the laws which govern the movement of water and petroleum through rocks with conditions of pressure as nearly as possible like those deep in the earth.

Sign in / Sign up

Export Citation Format

Share Document