Peru earthquake of May 31, 1970; engineering geology observations

1971 ◽  
Vol 61 (3) ◽  
pp. 511-533 ◽  
Author(s):  
Lloyd S. Cluff
Keyword(s):  
Ground Motion ◽  
Engineering Geology ◽  
Debris Avalanche ◽  
Soil Conditions ◽  
Average Speed ◽  
The North ◽  
The Poor ◽  
Debris Avalanches ◽  
Field Evidence ◽  
Secondary Factor

abstract At 3:23 p.m. local time, on May 31, 1970, an earthquake of magnitude 7 ¾; occurred approximately 15 miles off the coast of Peru, west of Chimbote. It is estimated that the earthquake took the lives of 70,000 people, caused 50,000 injuries, destroyed roughly 200,000 homes and buildings, and left approximately 800,000 people homeless. Within the affected region, roughly 40,000 square miles, many villages were almost totally destroyed and several were swept away. The single, most devastating event was the large debris avalanche that originated from the north peak of Huascaran, falling 12,000 ft and traveling 7 miles at an average speed of roughly 200 miles per hour to destroy the villages of Yungay and Ranrahirca. Field evidence strongly suggests that the area near Yungay and Ranrahirca will continue to be overridden by future debris avalanches. Damage resulting from vibrational effects was severe. The most intense vibrational damage occurred along the coast at Chimbote and Casma where most houses and buildings of adobe construction were destroyed or severely damage. Severe vibrational damage also occurred in cities and villages located in the Santa Valley at epicentral distances ranging from 60 to 100 miles inland. The single, most important factor contributing to the massive damage from ground motion was the poor adobe construction. The influence of the underlying geological and soil conditions was an important secondary factor.

Ritual and Landscape on the West Coast of Scotland: an Investigation of the Stone Rows of Northern Mull

1996 ◽  
Vol 62 ◽  
pp. 117-131 ◽  
Author(s):  
R.D. Martlew ◽  
C.L.N. Ruggles
Keyword(s):  
Bronze Age ◽  
West Coast ◽  
Late Bronze Age ◽  
Complex Relationship ◽  
The West ◽  
Radiocarbon Dates ◽  
Poor Condition ◽  
The North ◽  
The Poor ◽  
Field Evidence

In view of the theories of the astronomical significance of standing stones proposed by Alexander Thom, extensive fieldwork was undertaken during the 1970s and early 1980s in the west of Scotland to reassess the field evidence. Two groups of sites were identified from this work that seemed to support an astronomical interpretation, but the poor condition of many of the sites made identification of their original orientation problematical. Excavations were carried out at two damaged sites in one of the groups, in northern Mull, in order to identify the original positions of the stones. Radiocarbon dates from one of the sites, the first for a Scottish stone row, suggest construction in the Late Bronze Age. The alignment of the excavated rows, and the results of detailed theodolite surveys at and around the north Mull sites, suggest a more complex relationship between site locations, astronomical events, and the landscape than has hitherto been appreciated.

Stress estimates for the San Fernando, California, earthquake of February 9, 1971: Main event and thirteen aftershocks

1972 ◽  
Vol 62 (3) ◽  
pp. 721-750 ◽  
Author(s):  
M. D. Trifunac
Keyword(s):  
Ground Motion ◽  
Near Field ◽  
Strong Motion ◽  
Earthquake Ground Motion ◽  
The North ◽  
Field Evidence ◽  
North Eastern ◽  
San Fernando ◽  
And Migration ◽  
Stress Drops

Abstract The strong earthquake ground motion recorded in the center of and above the fault plane is combined with field evidence of faulting and instrumental studies of aftershocks to deduce stresses during and after the San Fernando earthquake of February 9, 1971. Stress computations based on Brune's near-field, shear-wave spectra, peak velocity of ground motion, energy calculated from the strong-motion record, and a model of circular dislocation give mutually consistent stress estimates, which suggest that the effective stress operating during the earthquake was approximately 100 bars, while during the earthquake it dropped several tens of bars. The energy of the main event is estimated to be 1022 dyne cm. Thirteen aftershocks, recorded during the first 6 min, were associated with stress drops ranging from 10 to 500 bars, these events clustering along the north-eastern end of the dislocation surface. The strong-motion accelerograms provide invaluable data for detailed investigations of the pattern of earthquake energy release during and immediately after an earthquake. Used for the first time in this study, strong-motion accelerograms gave an excellent picture of stress history and migration of seismic activity during the first 6 min.

scholarly journals A new approach to mapping landslide hazards: a probabilistic integration of empirical and physically based models in the North Cascades of Washington, USA

2019 ◽  
Vol 19 (11) ◽  
pp. 2477-2495
Author(s):  
Ronda Strauch ◽  
Erkan Istanbulluoglu ◽  
Jon Riedel
Keyword(s):  
Statistical Approach ◽  
Joint Probability ◽  
North Cascades ◽  
Physically Based Model ◽  
New Approach ◽  
The North ◽  
Debris Avalanches ◽  
Landslide Hazards ◽  
Infinite Slope Stability Model ◽  
Physically Based

Abstract. We developed a new approach for mapping landslide hazards by combining probabilities of landslide impacts derived from a data-driven statistical approach and a physically based model of shallow landsliding. Our statistical approach integrates the influence of seven site attributes (SAs) on observed landslides using a frequency ratio (FR) method. Influential attributes and resulting susceptibility maps depend on the observations of landslides considered: all types of landslides, debris avalanches only, or source areas of debris avalanches. These observational datasets reflect the detection of different landslide processes or components, which relate to different landslide-inducing factors. For each landslide dataset, a stability index (SI) is calculated as a multiplicative result of the frequency ratios for all attributes and is mapped across our study domain in the North Cascades National Park Complex (NOCA), Washington, USA. A continuous function is developed to relate local SI values to landslide probability based on a ratio of landslide and non-landslide grid cells. The empirical model probability derived from the debris avalanche source area dataset is combined probabilistically with a previously developed physically based probabilistic model. A two-dimensional binning method employs empirical and physically based probabilities as indices and calculates a joint probability of landsliding at the intersections of probability bins. A ratio of the joint probability and the physically based model bin probability is used as a weight to adjust the original physically based probability at each grid cell given empirical evidence. The resulting integrated probability of landslide initiation hazard includes mechanisms not captured by the infinite-slope stability model alone. Improvements in distinguishing potentially unstable areas with the proposed integrated model are statistically quantified. We provide multiple landslide hazard maps that land managers can use for planning and decision-making, as well as for educating the public about hazards from landslides in this remote high-relief terrain.

scholarly journals Checking the site categorization criteria and amplification factors of the 2021 draft of Eurocode 8 Part 1–1

2021 ◽  
Author(s):  
Roberto Paolucci ◽  
Mauro Aimar ◽  
Andrea Ciancimino ◽  
Marco Dotti ◽  
Sebastiano Foti ◽  
...  
Keyword(s):  
Numerical Simulations ◽  
Shear Wave ◽  
Ground Motion ◽  
Shear Wave Velocity ◽  
Soft Soil ◽  
Site Amplification ◽  
Soil Conditions ◽  
Eurocode 8 ◽  
Site Specific ◽  
Amplification Factors

AbstractIn this paper the site categorization criteria and the corresponding site amplification factors proposed in the 2021 draft of Part 1 of Eurocode 8 (2021-draft, CEN/TC250/SC8 Working Draft N1017) are first introduced and compared with the current version of Eurocode 8, as well as with site amplification factors from recent empirical ground motion prediction equations. Afterwards, these values are checked by two approaches. First, a wide dataset of strong motion records is built, where recording stations are classified according to 2021-draft, and the spectral amplifications are empirically estimated computing the site-to-site residuals from regional and global ground motion models for reference rock conditions. Second, a comprehensive parametric numerical study of one-dimensional (1D) site amplification is carried out, based on randomly generated shear-wave velocity profiles, classified according to the new criteria. A reasonably good agreement is found by both approaches. The most relevant discrepancies occur for the shallow soft soil conditions (soil category E) that, owing to the complex interaction of shear wave velocity, soil deposit thickness and frequency range of the excitation, show the largest scatter both in terms of records and of 1D numerical simulations. Furthermore, 1D numerical simulations for soft soil conditions tend to provide lower site amplification factors than 2021-draft, as well as lower than the corresponding site-to-site residuals from records, because of higher impact of non-linear (NL) site effects in the simulations. A site-specific study on NL effects at three KiK-net stations with a significantly large amount of high-intensity recorded ground motions gives support to the 2021-draft NL reduction factors, although the very limited number of recording stations allowing such analysis prevents deriving more general implications. In the presence of such controversial arguments, it is reasonable that a standard should adopt a prudent solution, with a limited reduction of the site amplification factors to account for NL soil response, while leaving the possibility to carry out site-specific estimations of such factors when sufficient information is available to model the ground strain dependency of local soil properties.

Periodicals as a Factor of Strengthening Soviet Power During the Transition Period (by the Materials of the North Caucasian Press)

2021 ◽  
pp. 36-43
Author(s):  
George A. Zaseev
Keyword(s):  
Transition Period ◽  
Soviet Power ◽  
North Caucasus ◽  
New Economic Policy ◽  
The North ◽  
The Poor ◽  
Ideological Struggle ◽  
The Press ◽  
School Issues ◽  
Revolutionary Period

The article examines the processes of the formation of mass periodicals in the North Caucasus in the first years of the existence of Soviet power. Its relevance is due to the poor study of the Soviet press of the 1920s, especially its development in the national regions of the state. It is shown that the functions of the Soviet press at the first stages of its existence were reduced to the ideological struggle against counter-revolution and party opposition. At the same time, the newspapers covered topics relevant to early Soviet everyday life: peasant and school issues, the life of auls, food appropriation, food tax, etc. The purpose of the article is to examine the process of development of the Bolshevik policy in the field of mass media in the post-revolutionary period. It is emphasized that for a number of regions of the North Caucasus, the appearance of their own periodicals is associated with the arrival of the Soviet regime, which is pursuing a protectionist policy in relation to the press. It was within the framework of this policy that a number of local publications were published in the languages of the peoples of the North Caucasus, for example, the Ossetian «Rastdzinad». The list of newspapers published in the region during the period under study is presented, among which, in terms of the duration of the issue, the thematic content, one can single out such newspapers as «Krasnaya Kabarda», «Kommunist», «Sovetskaya Autonomnaya Chechnya», and «Gorskaya Pravda». Special attention is paid to the substantive analysis of the «Kommunist» newspaper for 1920, which made it possible to identify the most relevant plots and topics related to the coverage of the events of the Civil War, as well as the processes taking place within the framework of the emerging new economic policy and nation-building. In the conclusion, it is concluded that the important role played by both the Soviet periodicals and the press of the national regions in the ideological support of the activities of the organs of Soviet power.

The Recent Cypraeidae of Northern New Zealand from the Kermadec Islands to the Poor Knights Islands, Southwest Pacific Ocean (Mollusca: Gastropoda: Cypraeidae)

The Festivus ◽  
2018 ◽  
Vol 50 (1) ◽  
pp. 36-54
Author(s):  
John Daughenbaugh
Keyword(s):  
New Zealand ◽  
Pacific Ocean ◽  
Continental Shelf ◽  
East Coast ◽  
Species Distributions ◽  
East Side ◽  
Tropical Eastern Pacific ◽  
The North ◽  
The Poor ◽  
Coastal Shelf

For researchers, isolated regions at the periphery of species’ distributions hold a peculiar fascination. The causes of their remoteness vary based on: distance (e.g. the Tropical Eastern Pacific), distance and countervailing currents (e.g. the Marquesas), location in a present day gyre (e.g. the Pitcairn Group) or the absence of present day means of veliger transport (e.g. the Vema Seamount). (Daughenbaugh & Beals 2013; Daughenbaugh 2015a & b, 2017). The northern New Zealand Region from the Kermadec Islands (Kermadecs) to the coastal and shelf areas in the northernmost part of New Zealand’s North Island (Northland), including the Poor Knights Islands (PKI), constitute the distributional boundaries for a number of Cypraeidae species. The boundaries are the result of the absence of coastal shelves along the east side of the Kermadec Ridge (Ridge) and precipitous drops to abyssal depths along Northland’s east coast continental shelf. Tropical waters, with their potential to transport Cypraeidae larvae, flow eastward from southern Queensland, Australia, entrained in the Tasman Front which terminates when reaching North Cape, the northernmost tip of Northland. There, the North Cape Eddy captures most of this flow while the remainder, the East Auckland Current (EAUC), flows intermittently southward along the eastern coastal, shelf and offshore areas of Northland into waters incapable of supporting Cypraeidae populations.

scholarly journals Investigating the influence of topographic irregularities and two-dimensional effects on surface ground motion intensity with one- and two-dimensional analyses

2014 ◽  
Vol 14 (7) ◽  
pp. 1773-1788 ◽  
Author(s):  
G. Ç. İnce ◽  
L. Yılmazoğlu
Keyword(s):  
Ground Motion ◽  
Site Response ◽  
Soil Conditions ◽  
Response Analysis ◽  
Two Dimensional ◽  
Ground Acceleration ◽  
Equivalent Linear ◽  
Local Soil ◽  
Different Depths ◽  
Earthquake Response Analysis

Abstract. In this work, the surface ground motion that occurs during an earthquake in ground sections having different topographic forms has been examined with one and two dynamic site response analyses. One-dimensional analyses were undertaken using the Equivalent-Linear Earthquake Response Analysis (EERA) program based on the equivalent linear analysis principle and the Deepsoil program which is able to make both equivalent linear and nonlinear analyses and two-dimensional analyses using the Plaxis 8.2 software. The viscous damping parameters used in the dynamic site response analyses undertaken with the Plaxis 8.2 software were obtained using the DeepSoil program. In the dynamic site response analyses, the synthetic acceleration over a 475-year return period representing the earthquakes in Istanbul was used as the basis of the bedrock ground motion. The peak ground acceleration obtained different depths of soils and acceleration spectrum values have been compared. The surface topography and layer boundaries in the 5-5' cross section which cuts across the study area west to east were selected in order to examine the effect of the land topography and layer boundaries on the analysis results, and were flattened and compared with the actual status. The analysis results showed that the characteristics of the surface ground motion change in relation to the varying local soil conditions and land topography.

scholarly journals Mass mortality of Northern Map Turtles (Graptemys geographica)

2015 ◽  
Vol 129 (1) ◽  
pp. 80 ◽  
Author(s):  
Jordan Catrysse ◽  
Emily Slavik ◽  
Jonathan Choquette ◽  
Ashley E. Leifso ◽  
Christina M. Davy
Keyword(s):  
Lake Erie ◽  
Mass Mortality ◽  
Species At Risk ◽  
Long Term Effects ◽  
North Shore ◽  
The North ◽  
The Poor ◽  
Map Turtles ◽  
Graptemys Geographica

We report a mass mortality of Northern Map Turtles (Graptemys geographica [LeSueur, 1817]) on the north shore of Lake Erie, Ontario, Canada. Thirty-five dead adult females were recovered from a nesting area over a period of four weeks. Predation and boat strikes were both excluded as potential cause of death, but the actual cause could not be determined because of the poor condition of the carcasses. Other possible explanations for the mortality include poisoning, drowning, and infection with an unidentified pathogen. Mass mortality in long-lived species, such as turtles, can have long-term effects on population growth and is a cause for concern in a species at risk.

scholarly journals Morphological analysis of hummocks in debris avalanche deposits around Mt Erciyes, central Turkey

2017 ◽  
Author(s):  
Yuichi S. Hayakawa ◽  
Hidetsugu Yoshida ◽  
Hiroyuki Obanawa ◽  
Ryutaro Naruhashi ◽  
Koji Okumura ◽  
...  
Keyword(s):  
Cross Sections ◽  
Flow Direction ◽  
Debris Avalanche ◽  
Caldera Wall ◽  
High Definition ◽  
Sector Collapse ◽  
Initial Flow ◽  
The North ◽  
Aircraft System ◽  
Central Turkey

Abstract. Debris avalanche caused by the sector collapse of a volcanic mountain often forms characteristic depositional landforms including hummocks. Not only sedimentological but also geomorphological analyses of debris avalanche deposits (DAD) are crucial to clarify the size, mechanisms, and processes of the debris avalanche. We investigate the morphology of hummocks newly identified in the DAD at the north-eastern flank of Mt. Erciyes in Kayseri, central Turkey, likely formed in the late Pleistocene. Using a remotely piloted aircraft system (RPAS) and the structure-from-motion multi-view stereo photogrammetry (SfM), we obtained high-definition digital elevation model (DEM) and orthorectified image of the DAD surface with hummocks. Detailed geometric features of the hummocks are investigated using the RPAS-derived high-definition DEM. The source volume of the DAD was also estimated by reconstructing the original shape of the mountain body using a lower-resolution satellite-based DEM. For this, topographic cross sections are examined based on the slopes around the scar that are regarded as the remnant topography preserved since the sector collapse. The spatial distribution of hummocks shows an unusual pattern regarding the distance-size relationships, i.e., anomalously concentrated in a certain distance from the source. The hummocks are found to be aligned toward the flow direction of the debris avalanche, suggesting the extensional regime of the debris avalanche. These facts indicate that this debris avalanche did not follow the typical flow type of debris avalanches observed in the other cases. Instead, the topographic constraints by former caldera wall and fault-induced lineaments could have strongly affected the flow course and pattern in this particular case: The pre-existing caldera wall topography could have acted as the topographic barriers for the debris avalanche to force the initial flow to turn northward, and the flow regime to be once compressional followed by extensional at the narrow and steepened outlet valley. Also, the estimated volume of the DAD 12–15 × 108 m3 gives its mean thickness of 60–75 m, which is much deeper than the reported cases of other DADs. This suggests that the debris avalanche could have flown down to the far downstream areas from the presently-observed limit of the DAD extent. Assessments of the DAD including the results of this study can provide further insights into the risk and mitigation of potential disasters in the study area.

scholarly journals Strategi dan Model Pemberdayaan Masyarakat Miskin di Sumatera Utara

2019 ◽  
Vol 9 (1) ◽  
pp. 21
Author(s):  
Yanhar Jamaluddin ◽  
Fitriani Fitriani ◽  
Safrida Safrida ◽  
Warjio Warjio
Keyword(s):  
Human Resources ◽  
Community Empowerment ◽  
Provincial Government ◽  
Effective Model ◽  
Change Model ◽  
The North ◽  
The Poor ◽  
The Government ◽  
Physical Weakness

This article was prepared on the background where the poor in North Sumatera are powerless and have no ability to place their position and role in government and development, whileefforts to empower the poor have not been optimally carried out by the North Sumatera Provincial government. This article was prepared to discuss ways to make the poor in North Sumatera powerless, and outline strategies and models to empower the poor in North Sumatera. The poor are powerless and the risk poses a factor of poverty, physical weakness, isolation, improvement, and powerlessness, the poor are not managed and tend to be left by the government, and are not liked by the community. The strategy for empowering the poor in North Sumatera can be carried out through the Need for Strengthening program, Strengthening Human Resources, Strengthening Institutions, Strengthening Access to Communication and Information, Strengthening Networks - Partnerships, and Strengthening Participation. While the effective model of Poor Community Empowerment in North Sumatera is an Advantage and Change Model (ACM)

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