scholarly journals Sismicidade do Nordeste do Brasil

2018 ◽  
Vol 1 (2) ◽  
Author(s):  
Joaquim M. Ferreira ◽  
Marcelo S. Assumpção

ABSTRACTA revised catalogue of earthquakes, which occurred in the Northeastern region of Brazilup to 1980, is presented. Most of the data come from historical macroseismic informationcollected in old publications and newspapers. Recent instrumental data is used to deriveempirical relations between magnitude and felt area in order to estimate mb magnitudesfor the events not recorded by seismographic stations. Macroseismic data for two largeevents (Pereiro 23.02.68, and Pacajus 20.11.80) are presented in detail. Epicentres of fourrecent events recorded at NAT were determined by combining the macroseismic andinstrumental data and used to define a preliminary value of the ratio K=Vp/Vs = 1.77 forthe region under study. A swarm of activity at Parazinho, Rio Grande do Norte, wasstudied in more detail to estimate the parameter b of the Gutenberg and Richter frequency-relation.

Author(s):  
Marcia Regina Farias da Silva ◽  
Janine Beatriz Torres ◽  
Nildo da Silva Dias ◽  
Alexandre de Oliveira Lima

Along the Brazilian history, the federal government has invested in the construction of large-scale water works in the Northeastern region, aiming to fight drought in the Semiárido and to finish with the scarcity of water by means of public policies. However, the climatic context makes drought a natural characteristic of the Northeastern region and cannot be fought against, as it is a natural phenomenon in the area. The objective of the present paper is to investigate how social technologies implemented in the Semiárido have contributed to the strengthening of women’s production capacity in the Hipólito community located in the Mossoró municipality, (State of Rio Grande do Norte, Northeastern Brazil), with the implementation of fertilized cisterns, aiming at gender equality and sustainable agriculture as preconized by Agenda 2030. As a methodological procedure, a qualitative research was carried out, adopting the participatory observation and the focal group techniques. Twelve women who integrate the Mulheres em Ação group participated in the study. It was observed that women positively perceive the impacts of the social technologies of the Um Milhão de Cisternas (P1MC) and Uma Terra e Duas Águas (P1+2) programs in the Hipólito community. Moreover, agriculture practices involved in the construction of the water reuse technology in their yards yielded positive expectations regarding production by the addition of another social technology that will make a larger volume of water available to the community. It is concluded that social technologies coexisting with the Semiárido have contributed to a new territorial development model, consonant with the Semiárido characteristics.


2021 ◽  
Vol 35 (1) ◽  
pp. 92-102
Author(s):  
Alex Bortolon de Matos ◽  
Pedro Antonio Roehe Reginato ◽  
Gustavo Barbosa Athayde

This study aims to evaluate the structural compartmentation of the Guarani Aquifer System (GAS) in the northeastern region of the Rio Grande do Sul (RS) state. For this purpose, an integrated analysis of 747 morphostructural lineaments identified in the scale 1:1,000,000 with geometry features and potentiometry of the GAS was performed. Based on this evaluation, a main set of structures, N30W and N60E oriented, responsible for the GAS compartmentation within the study area, was identified. These directions are related to the main tectonic structures that originated from the basement of the Paraná Basin, which could indicate that these identified structures are part of large fault systems in this region. The variations in the GAS potentiometry and altimetry of the top related to the compartmentation show the existence of several blocks formed under the influence of NW and NE structures located mainly in the large valleys, which sometimes work as a discharge zone of the aquifer. According to the analysis, the GAS in the northeastern region of RS seems to be divided into compartments of different sizes. This structural and geometrical framework imposed by tectonic structures influences the GAS potentiometry and flow dynamics.


1974 ◽  
Vol 64 (1) ◽  
pp. 73-85 ◽  
Author(s):  
Otto W. Nuttli ◽  
James E. Zollweg

abstract Felt areas of earthquakes in the central United States are known to increase sizeably with small increases in magnitude. In order to establish a quantitative relation between magnitude and felt area, 22 recent earthquakes were studied, resulting in the empirical equation m b = 2.65 + 0.098 f + 0.054 f 2 for f ≦ 6 where ƒ is the logarithm to the base 10 of the felt area in square kilometers. This equation can be used to estimate the magnitude of earthquakes in the central United States for which there are intensity maps but no instrumental data. Furthermore, from the equation one can determine that the limit of perceptibility corresponds to a sustained, hard-rock, vertical-component particle velocity of about 22μ/sec.


1996 ◽  
Vol 39 (5) ◽  
Author(s):  
I. Cecic ◽  
R. M. W. Musson ◽  
M. Stucchi

In contrast to the case of instrumental data, the procedures for epicentral parameter determination (coordinates and I0) from macroseismic data are not very well established. Although there are some "rules", upon which most seismologists agree (centre of the isoseismal of largest degree, and so on), the practical application of, such rules displays many problems. Therefore, it is commonly seismologists' practice to find their own pro cedures and solutions; this is particularly evident in the more complicated cases, Such as offshore epicentres or, as in many cases of historical earthquakes, poor sets of data. One of the major consequences is that parametric catalogues are not homogeneous with respect to macroseismic parameters; moreover, merging catalogues compiled according to different criteria can introduce high noise in any catalogue built in such a way. In order to survey the current practice of epicentre determination from macroseismic data in Europe, a set of cases was distributed to the participants of the first meeting of the ESC WG "Macroseismology". A comparison of the 15 sets of results provided by 16 authors, who gave their own solutions and the explanation., of the adopted procedures is given, showing that in some cases the ideas and results are rather distant.


Author(s):  
O. Asmanov ◽  
M. Daniyalov ◽  
M. Mirzaliyev ◽  
Kh. Magomedov ◽  
Z. Adilov

The instrumental data on the source and macroseismic manifestations of the earthquake that occurred on April 16, 2013, with MS=4.5 in the territory of Dagestan are given. An isoseist map was compiled on the MSK-64 scale based on macroseismic data and data from the network of seismic stations in the Dagestan branch of the GS RAS. The data on historical earthquakes recorded in the Kichi-Gamra earthquake area are given


Author(s):  
И.Ю. Дмитриева ◽  
А.А. Саяпина ◽  
С.В. Горожанцев ◽  
С.С. Багаева

В рассматриваемой статье проведен анализ и представлены данные о землетрясении 17 октября 2018 г. в 15h55m по Гринвичу с интенсивностью сотрясений в эпицентре 5 баллов, произошедшего на окраине села Яндаре Республики Ингушетия. По инструментальным данным сетей сейсмических станций NOGSR, OBGSR, DAGSR получено следующее решение параметров землетрясения: 43,27N, 44,92E, h12 км, КР11,5. Приведены сведения по истории сейсмичности очаговой зоны исследуемого землетрясения за последние 150 лет. Очаг землетрясения приурочен к активному Сунженскому разлому. Рассмотрены форшоковая активность и немногочисленная серия афтершоков. Для землетрясения был рассчитан механизм очага по знакам первых вступлений продольных Pволн на 48 станциях, хорошо окружавших эпицентр и расположенных на расстояниях 0,3 50,5 км. Согласно полученному решению землетрясение возникло под действием преобладающих сжимающих напряжений. Тип подвижки в очаге соответствовал взбросу с правосторонним сдвигом по плоскости NP2 с юговосточным простиранием и левостороннему сдвигу с компонентами взброса по плоскости NP1 с субширотным простиранием. Для сбора макросейсмических данных сотрудниками СевероОсетинского филиала ФИЦ ЕГС РАН был осуществлен выезд в эпицентральную зону и близлежащие районы. Оценка интенсивности проводилась на основе шкалы ШСИ 17. Землетрясение с интенсивностью 5 баллов проявилось в населенных пунктах Яндаре, Троицкое, Карабулак. Колебания ощущались в Сунже, Барсуках и Плиево силой 4 балла, Назрани 34 балла. В населенных пунктах Магас, АлиЮрт, Средние Ачалуки ощутимость землетрясения составила 3 балла. В семи населенных пунктах колебания проявились интенсивностью в 2 балла. Во Владикавказе землетрясение ощущалось на верхних этажах многоэтажных зданий. Данные о проявлениях Яндарского землетрясения интересны с точки зрения анализа распределения интенсивности сотрясений, изучения сейсмичности региона в целом, а также связи с геологическим строением территории The article analyzes and presents the data on the earthquake on October 17 at 15h55m GMT, which occurred on the outskirts of the village of Yandare of the Republic of Ingushetia. Intensity of the shok equaled 5 in the epicenter. According to instrumental data of networks of seismic stations NOGSR, OBGSR, DAGSR the following solution of parameters of an earthquake is received: 43,27N, 44,92E, h12 km, KР11,5. The history of seismicity of the focal zone of the investigated earthquake for the last 150 years is studied. The earthquake is confined to the active Sunzha fault. The forshock activity and a few series of aftershocks are considered. For the earthquake, the mechanism of the focus was calculated according to the signs of the first arrivals of longitudinal Pwaves at 48 stations well surrounding the epicenter and located at distances 0,3 50,5 km. According to the received decision, the earthquake appeared under the influence of prevailing compression stresses, the type of movement the reverse fault. For collecting macroseismic data departure in an epicentralny zone and nearby areas was carried out. Evaluation of intensity was carried out on the basis of theSeismic intensity scale (SHSI17). The earthquake with an intensity of 5 points was manifested in the settlements of Yandare, Troitskoye, Karabulak. Fluctuations were felt in Sunzha, Barsuki and Plievo force 4 points, Nazran 34 points. In the settlements of Magas, AliYurt, Middle Achaluki, the sensitivity of the earthquake was 3 points. In seven settlements, the fluctuations showed an intensity of 2 points. In Vladikavkaz earthquake was felt on the upper floors of multistorey buildings. Data on the manifestations of the Yandaryearthquake are interesting from the point of view of the analysis of the distribution of the intensity of concussions, the study of the seismicity of the region as a whole, as well as the connection with the geological structure of the territory.


2018 ◽  
Vol 7 (2) ◽  
pp. 107
Author(s):  
Marcelo Assumpção ◽  
Mario Takeya ◽  
Joaquim Mendes Ferreira ◽  
João da Mata Costa ◽  
Cláudia Moraes Sophia

RESUMO. As magnitudes dos principais sismos da série de João Câmara de 1986-1987 foram calculadas com estações regionais e telessísmicas. Correções das estações foram determinadas permitindo obter-se valores de magnitudes mais homogêneos e com menores desvios padrão. De agosto de 1986 a fevereiro de 1987, 30 sismos tiveram magnitudes maiores ou iguais a 3,5. A magnitude do maior sismo da série (30/11/86 às 05:19:48) foi m = 5,03 ± 0,05. Uma relação empírica entre magnitude e duração do sinal (m = c1 log D + c3) na estação JC01, em João Câmara, foi estabelecida permitindo um cálculo mais rápido de magnitude de microtremores. Para durações medidas até 1 mm pico-a-pico no sismograma, c1 = 2,05 e c3 = –1,61 para m ? 2. O exame das relações frequência-magnitude (log N = a – b m) indica que o coeficiente c1 deve ser menor para magnitudes abaixo de 2, aproximadamente. Para a atividade geral de João Câmara, foi encontrado um valor típico do parâmetro b de 1,12 ± 0,04. Não foi observada variação significativa no valor de b antes e depois do maior sismo de 30/11/1986.Palavras-chave: terremoto, onda de cauda, correções de estação, Rio Grande do Norte. DETERMINATION OF MAGNITUDES AND MAGNITUDE-FREQUENCY RELATION FOR THE EARTHQUAKES OF JOÃO CÂMARA, RNABSTRACT. Magnitudes of the major events of the 1986-1987 João Câmara earthquake swarm were calculated with regional and teleseismic stations. Station corrections were determined allowing more homogeneous magnitudes with smaller standard deviations. From August 1986 to February 1987, 30 events had magnitudes greater than 3.5. The largest (November 30, 1986 at 05:19:48) had m = 5.03 ± 0.05. An empirical relation between magnitude, m, and signal duration, D, (m = c1 log D + c3) at the local station JC01 was established allowing quick estimates of magnitudes for microearthquakes. For durations measured from the P arrival to coda amplitude of 1 mm peak-to-peak, c1 = 2.05 and c3 = –1.61 for magnitudes greater than about 2. The study of the frequency-magnitude relation (log N = a – b m) shows that the coefficient c1 must be smaller for magnitudes less than about 2. For the whole activity of João Câmara, a typical b-value of 1.12 ± 0.04 was found. No significant variation was observed in the b-value before and after the main event of November 30, 1986.Keywords: earthquake, coda wave, station corrections, Rio Grande do Norte State.


2018 ◽  
Vol 2 (1) ◽  
pp. 17
Author(s):  
Fábio Soares ◽  
Marcela Daher ◽  
Raul Perrelli ◽  
José Armando Torres Moreno ◽  
Stephen Ferrari

<p style="text-align: justify;">Atualmente, quarenta e uma espécies de morcegos são conhecidas para as restingas do Brasil. No entanto, a maioria dos estudos sobre morcegos das restingas são limitados às regiões sul e sudeste do Brasil, deixando a região nordeste com uma lacuna de conhecimento. O presente artigo apresenta dados sobre morcegos capturados em três áreas de restinga do município de Tibau do Sul, Rio Grande do Norte, levantados a partir de uma amostragem de curta duração. Redes de neblina para captura de morcegos foram armadas próximas ao solo e sobre o corpo d’água. Foram capturados 38 indivíduos de seis espécies de duas famílias: cinco Phyllostomidae e um Molossidae. O morcego <em>Carollia perspicillata</em> (Linnaeus, 1758) foi a espécie mais abundante. Apresentamos aqui a primeira lista de morcegos capturados em área de restinga para o Rio Grande do Norte.</p><p style="text-align: justify;"><strong>Palavras chave</strong>: Molossidae, Nordeste, Novo registro, Phyllostomidae, Tibau do Sul.</p><p style="text-align: justify;"><strong>Abstract</strong>: Currently, forty-one species of bats are known to occur in the restingas of Brazil. However, most studies on restingas’ bats are limited to the south and southeastern regions of Brazil, leaving the northeastern region with a gap of knowledge. The present article presents data on bats captured in three areas of restinga of the municipality of Tibau do Sul, Rio Grande do Norte, collected from a short-term sampling. Mist nets were used to capture bats near the ground and the water bodies. Were captured 38 individuals of six species and two families: five Phyllostomidae and one Molossidae. The bat <em>Carollia perspicillata</em> (Linnaeus, 1758) was the most abundant species. We present here the first list of bats captured in the restinga area for the Rio Grande do Norte State.</p><p style="text-align: justify;"><strong>Key words</strong>: Molossidae, New record, Northeast, Phyllostomidae, Tibau do Sul.</p>


2016 ◽  
Vol 9 (3) ◽  
pp. 202-206
Author(s):  
Raphael Aquino Heleodoro ◽  
Antonio Agudelo ◽  
Ricardo Andreazze

This study presents a list of the mantis species from the Brazilian state of Rio Grande do Norte and their distribution within the state. The records are derived from specimens deposited in the “Adalberto Antonio Varela Freire” Entomological Collection at the Federal University of Rio Grande do Norte. This collection holds a total of 1,816 specimens, representing 30 species distributed in 16 genera distributed in 44 localities. There are two new records to Brazil, 10 to the Northeastern region of Brazil (and Caatinga biome) and 25 to the Rio Grande do Norte.Os Mantodea (Dictyoptera: Insecta) do Rio Grande do Norte, Brasil: Primeira Lista de Espécies e Ocorrências GeográficasResumo. Este trabalho apresenta a primeira lista de espécies de louva-a-deus do Rio Grande do Norte, bem como sua distribuição dentro do Estado. Os registros das espécies são oriundos de espécimes depositados na Coleção Entomológica “Adalberto Antonio Varela Freire”, localizada na Universidade Federal do Rio Grande do Norte. Essa coleção possui um total de 1.816 espécimes de Mantodea depositados, representando 30 espécies distribuídas em 16 gêneros.


2021 ◽  
Vol 41 ◽  
Author(s):  
Givaldo B. Silva Filho ◽  
Hisadora A.S.C Bom ◽  
Silvio M.C. Fonseca ◽  
Érica A. Costa ◽  
Beatriz S.A.S. Santos ◽  
...  

ABSTRACT: Equine coital exanthema is a venereal infectious disease poorly reported in horses in Brazil and was never described in the northeastern region of the country. This work aims to describe the clinical and pathological aspects of an outbreak of equine coital exanthema caused by equid alphaherpesvirus 3, occurred in a herd of horses at the semiarid region of the State of Rio Grande do Norte. Main clinical signs consisted of anorexia, hiporexia, fibrinous or purulent secretion in the penis mucosa and vagina. Two mares presented mild to minimal lesions that consisted of scars in the mucosa of the vagina and in the perivulvar region. In a stallion the disease consisted of severe, multifocal, umbilicated-exanthematous ulcers of approximately 1cm in diameter on the penis mucosa. Other areas where ulcers and crusts were focally observed included the skin of the scrotum and on the lips and mucocutaneous junctions of the oral cavity. Histologically, the main lesion consisted of multifocal severe ulcerative and fibrinous necrotizing balanoposthitis and mild multifocal necrotizing, lymphocytic dermatitis in the lips and scrotum. The equide alphaherpesvirus 3 DNA was amplified in blood samples and penis mucosa using the PCR technique. This is the first report of molecular diagnosis of equine coital exanthema affecting horses in northeastern Brazil. Further studies should be carried out in order to investigate the epidemiology and the importance of this herpetic disease in the country.


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