scholarly journals Monitoring potential ionospheric changes caused by Van earthquake (Mw 7.2)

2018 ◽  
Author(s):  
Samed Inyurt ◽  
Selcuk Peker ◽  
Cetin Mekik
Keyword(s):  
Solar Activity ◽  
Local Time ◽  
Earthquake Prediction ◽  
Statistical Test ◽  
Van Earthquake ◽  
The North ◽  
The Times ◽  
Geomagnetic Activities

Abstract. Many scientists from different disciplines have studied earthquakes for many years. As a result of these studies, it has been proposed that some changes take place in the ionosphere layer before, during or after earthquakes, and the ionosphere should be monitored in earthquake prediction studies. This study investigates the changes in the ionosphere created by the earthquake with magnitude of Mw=7.2 in the northwest of the Lake Erçek which is located to the north of the province of Van in Turkey on 23 October 2011 and at 1.41 pm local time (−3 UT) with the epicenter of 38.75° N, 43.36° E using the TEC values obtained by the Global Ionosphere Models (GIM) created by IONOLAB-TEC and CODE. In order to see whether the ionospheric changes obtained by the study in question were caused by the earthquake or not, the ionospheric conditions were studied by utilizing indices providing information on solar and geomagnetic activities (F10.7 cm, Kp, Dst). One of the results of the statistical test on the TEC values obtained from the both models, positive and negative anomalies were obtained for the times before, on the day of and after the earthquake, and the reasons for these anomalies are discussed in detail in the last section of the study. As the ionospheric conditions in the analyzed days were highly variable, it was thought that the anomalies were caused by geomagnetic effects, solar activity and the earthquake.

scholarly journals Monitoring potential ionospheric changes caused by the Van earthquake (<i>M</i><sub>w</sub>7.2)

2019 ◽  
Vol 37 (2) ◽  
pp. 143-151 ◽  
Author(s):  
Samed Inyurt ◽  
Selcuk Peker ◽  
Cetin Mekik
Keyword(s):  
Solar Activity ◽  
Local Time ◽  
Earthquake Prediction ◽  
Statistical Test ◽  
Van Earthquake ◽  
The North ◽  
The Van Earthquake ◽  
The Times ◽  
Geomagnetic Activities

Abstract. Many scientists from different disciplines have studied earthquakes for many years. As a result of these studies, it has been proposed that some changes take place in the ionosphere layer before, during or after earthquakes, and that the ionosphere should be monitored in earthquake prediction studies. This study investigates the changes in the ionosphere created by the earthquake with a magnitude of Mw=7.2 in the northwest of Lake Erçek, which is located to the north of the province of Van in Turkey on 23 October 2011 and at 13:41 local time (−3 UT) with the epicenter of 38.75∘ N, 43.36∘ E using the TEC values obtained by the global ionosphere models (GIMs) created by IONOLAB-TEC and CODE. In order to see whether the ionospheric changes obtained by the study in question were caused by the earthquake or not, the ionospheric conditions were studied by utilizing indices providing information on solar and geomagnetic activities (F10.7 cm, Kp, Dst). One of the results of the statistical test of the TEC values obtained from both models is positive and negative anomalies obtained for the times before, on the day of and after the earthquake, and the reasons for these anomalies are discussed in detail in the last section of the study. As the ionospheric conditions on the analyzed days were highly variable, it was thought that the anomalies were caused by geomagnetic effects, solar activity and the earthquake.

scholarly journals Monitoring potential ionosphere changes caused by Van earthquake (Mw 7.2) using GNSS measurements

2018 ◽  
Author(s):  
Selcuk Peker ◽  
Samed Inyurt ◽  
Cetin Mekik
Keyword(s):  
Solar Activity ◽  
Local Time ◽  
Statistical Test ◽  
Interdisciplinary Studies ◽  
Van Earthquake ◽  
The North ◽  
Related Part ◽  
The Times ◽  
Gnss Measurements ◽  
Geomagnetic Activities

Abstract. Several scientists from different disciplines have studied earthquakes for many years. As a result of these studies, it has been proposed that some changes take place in the ionosphere layer before, during or after earthquakes, and the ionosphere should be monitored in earthquake prediction studies. This study investigates the changes in the ionosphere created by the earthquake with magnitude of Mw=7.2 in the northwest of the Lake Erçek which is located to the north of the province of Van in Turkey on 23 October 2011 and at 1.41 pm local time (−3 UT) with the epicenter of 38.758° N, 43.360° E using the TEC values obtained by the Global Ionosphere Models (GIM) created by IONOLAB-TEC and CODE. In order to see whether the ionospheric changes obtained by the study in question were caused by the earthquake or not, the ionospheric conditions were studied by utilizing indices providing information on solar and geomagnetic activities (F10.7 cm, Kp, Dst). As a result of the statistical test on the TEC values obtained from the both models, positive and negative anomalies were obtained for the times before, on the day of and after the earthquake, and the reasons for these anomalies are discussed in detail in the last section of the study. As the ionospheric conditions in the analyzed days were highly vibrant, it was thought that the anomalies were caused by geomagnetic effects, solar activity and the earthquake. The authors believe that interdisciplinary studies are needed to distinguish the earthquake-related part of the anomalies in question.

Short-term tilt anomalies preceding local earthquakes near San Jose, California

1980 ◽  
Vol 70 (6) ◽  
pp. 2221-2228
Author(s):  
C. E. Mortensen ◽  
E. Y. Iwatsubo
Keyword(s):  
Partial Recovery ◽  
San Jose ◽  
Short Term ◽  
Origin Time ◽  
Central California ◽  
Local Earthquakes ◽  
The North ◽  
Surface Creep ◽  
The Times ◽  
Black Mountain

abstract A tilt anomaly preceded a pair of earthquakes (ML = 4.2, origin time 0014 UTC, and ML = 3.9, origin time 0018 UTC, both on 29 August 1978) on the Calaveras Fault near San Jose, California. These earthquakes occurred at hypocentral depths of 8.5 and 9.0 km, respectively, and were located 6.7 and 5.2 km northwest of the Mt. Hamilton tiltmeter site. The anomaly is similar in shape and time scale to signals observed on other tiltmeters at the times of recorded surface creep events. The anomaly began approximately 40 hr before the earthquake pair and consisted of gradual down-to-the-east tilting followed by rapid tilting down-to-the-north-northeast at a rate of 12 μrad/hr. This was followed by 1 hr of rapid down-to-the-east tilting amounting to 1.5 μrad. The maximum peak tilt of 10.6 μrad down-to-the-northeast was followed by gradual decelerating tilting down-to-the-southwest constituting partial recovery. An anomaly of nearly identical form, but smaller in amplitude and duration, preceded an ML = 2.2 aftershock on 5 September 1978. Other nearby earthquakes as large as ML = 4.7 have occurred without accompanying creep-like signals. A similar, but a much smaller (0.74 μrad) creep-event-like signal preceded an ML = 3.5 earthquake with epicenter 3 km east of the Black Mountain tiltmeter site. In general, however, short-term tilt anomalies such as these are not observed to precede local earthquakes within the central California tiltmeter network. The tilt signal preceding the 29 August earthquake pair may be interpreted in terms of a model of a propagating creep event, at depth, associated with seismic failure at a “stuck” patch on the fault. However, the data are not adequate to constrain the model sufficiently to constitute a test of the hypothesis.

Periodicities in the north-south asymmetry of solar activity

Solar Physics ◽  
1989 ◽  
Vol 119 (2) ◽  
pp. 411-414 ◽  
Author(s):  
G. Vizoso ◽  
J. L. Ballester
Keyword(s):  
Solar Activity ◽  
The North ◽  
South Asymmetry

scholarly journals Regularity of the north-south asymmetry of solar activity

2002 ◽  
Vol 383 (2) ◽  
pp. 648-652 ◽  
Author(s):  
K. J. Li ◽  
J. X. Wang ◽  
S. Y. Xiong ◽  
H. F. Liang ◽  
H. S. Yun ◽  
...  
Keyword(s):  
Solar Activity ◽  
The North ◽  
South Asymmetry

scholarly journals Topside equatorial zonal ion velocities measured by C/NOFS during rising solar activity

2014 ◽  
Vol 32 (2) ◽  
pp. 69-75 ◽  
Author(s):  
W. R. Coley ◽  
R. A. Stoneback ◽  
R. A. Heelis ◽  
M. R. Hairston
Keyword(s):  
Solar Activity ◽  
Local Time ◽  
Geomagnetic Field ◽  
General Pattern ◽  
Magnetic Latitude ◽  
Ion Drifts ◽  
F Region ◽  
Westerly Flow ◽  
Solar Local Time ◽  
Ion Velocity

Abstract. The Ion Velocity Meter (IVM), a part of the Coupled Ion Neutral Dynamic Investigation (CINDI) instrument package on the Communication/Navigation Outage Forecast System (C/NOFS) spacecraft, has made over 5 yr of in situ measurements of plasma temperatures, composition, densities, and velocities in the 400–850 km altitude range of the equatorial ionosphere. These measured ion velocities are then transformed into a coordinate system with components parallel and perpendicular to the geomagnetic field allowing us to examine the zonal (horizontal and perpendicular to the geomagnetic field) component of plasma motion over the 2009–2012 interval. The general pattern of local time variation of the equatorial zonal ion velocity is well established as westward during the day and eastward during the night, with the larger nighttime velocities leading to a net ionospheric superrotation. Since the C/NOFS launch in April 2008, F10.7 cm radio fluxes have gradually increased from around 70 sfu to levels in the 130–150 sfu range. The comprehensive coverage of C/NOFS over the low-latitude ionosphere allows us to examine variations of the topside zonal ion velocity over a wide level of solar activity as well as the dependence of the zonal velocity on apex altitude (magnetic latitude), longitude, and solar local time. It was found that the zonal ion drifts show longitude dependence with the largest net eastward values in the American sector. The pre-midnight zonal drifts show definite solar activity (F10.7) dependence. The daytime drifts have a lower dependence on F10.7. The apex altitude (magnetic latitude) variations indicate a more westerly flow at higher altitudes. There is often a net topside subrotation at low F10.7 levels, perhaps indicative of a suppressed F region dynamo due to low field line-integrated conductivity and a low F region altitude at solar minimum.

scholarly journals The first record of The Blue Admiral Kaniska canace Linnaeus, 1763 (Nymphalidae: Lepidoptera) from Bangladesh

2018 ◽  
Vol 10 (10) ◽  
pp. 12429-12431
Author(s):  
Amit Kumer Neogi ◽  
Md Jayedul Islam ◽  
Md Shalauddin ◽  
Anik Chandra Mondal ◽  
Safayat Hossain
Keyword(s):  
Local Time ◽  
First Record ◽  
Biodiversity Hotspot ◽  
The North ◽  
North Eastern ◽  
Reserve Forest ◽  
Current Article ◽  
North Eastern Part

Moulvibazar district has been recognized as one of the biodiversity rich pockets close to the boundary side of Assam of India and situated in the North-eastern part of Bangladesh. Adompur reserve forest is one of the biodiversity hotspot  in the North-eastern. The current article confirm, the presence of  Kaniska canace Linnaeus, 1763, (Nymphalidae: Lepidoptera) which was not previously recorded in Bangladesh. This species was first recorded on 17 March 2017 at 15.30 (GMT+6) local time in the coordination of  N 24°18'9.46"; E 91°55'4.23" at Kauyargola   forest   beat, Adampur reserve forest in Moulvibazar District.  

scholarly journals Manipuri Lores: Folktales, Cultural History and Anthologies

2021 ◽  
Vol 7 (3) ◽  
pp. 140-143
Author(s):  
Yaisna Rajkumari ◽  
Keyword(s):  
Cultural History ◽  
Direct Link ◽  
The Past ◽  
The North ◽  
North Eastern ◽  
Indian State ◽  
History Of ◽  
The Times

The paper will establish a connection between folktales and the cultural history of a region, particularly with respect to the Indian state of Manipur. It is premised on the belief that a study of folktales can alert us not only to the various interconnections between folktales and the cultural history of a place but also help analyse the dynamics of the publication of the anthologies of folktales in relation to this cultural history. The paper will include analyses of Meitei and tribal tales pertaining to the nationalist phase and contemporary period in the history of the North Eastern Indian state of Manipur and look at how in the past few years, compilers and translators have incorporated versions of tales different from the earlier anthologies, establishing a direct link between the tales and the times of their publication.

scholarly journals Tree-ring radiocarbon reveals reduced solar activity during Younger Dryas cooling

2020 ◽  
Author(s):  
Adam Sookdeo ◽  
Bernd Kromer ◽  
Florian Adolphi ◽  
Jürg Beer ◽  
Nicolas Brehm ◽  
...  
Keyword(s):  
Solar Activity ◽  
Tree Ring ◽  
North Atlantic ◽  
Little Ice Age ◽  
Ice Core ◽  
Younger Dryas ◽  
Ice Age ◽  
The North ◽  
Long Duration ◽  
Clear Sign

&lt;p&gt;The Younger Dryas stadial (YD) was a return to glacial-like conditions in the North Atlantic region that interrupted deglacial warming around 12900 cal BP (before 1950 AD). Terrestrial and marine records suggest this event was initiated by the interruption of deep-water formation arising from North American freshwater runoff, but the causes of the millennia-long duration remain unclear. To investigate the solar activity, a possible YD driver, we exploit the cosmic production signals of tree-ring radiocarbon (&lt;sup&gt;14&lt;/sup&gt;C) and ice-core beryllium-10 (&lt;sup&gt;10&lt;/sup&gt;Be). Here we present the highest temporally resolved dataset of &lt;sup&gt;14&lt;/sup&gt;C measurements (n = 1558) derived from European tree rings that have been accurately extended back to 14226 cal BP (&amp;#177;8, 2-&amp;#963;), allowing precise alignment of ice-core records across this period. We identify a substantial increase in &lt;sup&gt;14&lt;/sup&gt;C and &lt;sup&gt;10&lt;/sup&gt;Be production starting at 12780 cal BP is comparable in magnitude to the historic Little Ice Age, being a clear sign of grand solar minima. We hypothesize the timing of the grand solar minima provides a significant amplifying factor leading to the harsh sustained glacial-like conditions seen in the YD.&lt;/p&gt;

scholarly journals The profile of unlabeled trees

2005 ◽  
Vol DMTCS Proceedings vol. AD,... (Proceedings) ◽  
Author(s):  
Bernhard Gittenberger
Keyword(s):  
Local Time ◽  
Joint Distribution ◽  
Random Trees ◽  
Rooted Trees ◽  
Brownian Excursion ◽  
Level Number ◽  
International Audience ◽  
The Times ◽  
Simply Generated Trees

International audience We consider the number of nodes in the levels of unlabeled rooted random trees and show that the joint distribution of several level sizes (where the level number is scaled by $\sqrt{n}$) weakly converges to the distribution of the local time of a Brownian excursion evaluated at the times corresponding to the level numbers. This extends existing results for simply generated trees and forests to the case of unlabeled rooted trees.

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