The Application and Research of the Double Difference Method about the 2004 Ludian Earthquake Sequence

2013 ◽  
Vol 726-731 ◽  
pp. 3123-3127
Author(s):  
Ba Teer Wu ◽  
Er Gen Gao ◽  
Ye Wu
Keyword(s):  
Difference Method ◽  
Conclusive Evidence ◽  
Earthquake Sequence ◽  
Double Difference ◽  
Time Data ◽  
Earthquake Forecast ◽  
Earthquake Parameters ◽  
Ludian Earthquake ◽  
The North ◽  
North And South

The paper is utilizes the double difference method of to relocate the north and south earthquake belt's Ludian earthquake sequence to obtained the Ludian earthquake sequence's detailed earthquake parameters. And at the same time we have established an whole set of perfect method in data processing and result analysising. Have the ability of useing'the north and south earthquake belt earthquake to strengthen the monitor's real time data to accuratly relocate the medium intensity earthquake sequenc of the north and south belt. Thus,we could produce the more accurate earthquake parameter, and short provides a more conclusive evidence into the warning area division and earthquake forecast.

The Application and Research of the Double Difference Method about Regional and Telseismic Earthquake

2012 ◽  
Vol 622-623 ◽  
pp. 1651-1654
Author(s):  
Ba Teer Wu ◽  
Er Gen Gao ◽  
Ye Wu
Keyword(s):  
Travel Time ◽  
Basic Principle ◽  
Difference Method ◽  
Earthquake Sequence ◽  
Double Difference ◽  
Earth Model

The paper rests on the basic principle of the double difference method, through using Kennett and Engdahl(1991)’s IASPEI Earth model which can be used in computation theoretical travel time in the condition of regional and telseismic earthquake .We have developed a double difference program which can be used in the regional and teleseismic earthquake. And utilizes this program to relocate the Jiashi Ms 6.8 earthquake sequence in Xinjiang province on 24/2/2,003, obtained a quite good result.

The Earthquake’s Relative Location Algorithms Effected by Data Recorded at Nearby Station

2012 ◽  
Vol 588-589 ◽  
pp. 1988-1998
Author(s):  
Ba Teer Wu ◽  
Er Gen Gao
Keyword(s):  
Difference Method ◽  
Earthquake Sequence ◽  
Double Difference ◽  
Relative Location ◽  
The Absolute ◽  
Simulated Calculation ◽  
Hypocenter Depth ◽  
Distant Station

Based on the primary theory of location, it is found that the data recorded at nearby stations are applicable in double difference relocation algorithm, but not in other relative location algorithms. Equation derivation and simulated calculation demonstrate that double difference algorithm allows to get the absolute locations of earthquakes with certain accuracy by using the nearby stations records. The errors of relative location become larger when using the nearby station records alone than that using the distant station records. Combining the nearby and distant station records, the best locations are obtained. In the case that hypocenter depth is far less than the epicenter distance without depth phases available, only the relative epicenter distribution could be obtained accurately by double difference method, the depth determined would be not stable. The relocation test of a part of aftershocks in Jiashi earthquake sequence verify the effect of nearby station records on the double difference algorithm mentioned above.

High resolution seismicity catalog of the Marmara Sea region during the 2009-2014 period using template matching

2020 ◽  
Author(s):  
Hayrullah Karabulut ◽  
Olivier Lengliné ◽  
Jean Schmittbuhl ◽  
Emanuela Matrullo ◽  
Michel Bouchon
Keyword(s):  
Template Matching ◽  
Double Difference ◽  
First Year ◽  
Marmara Sea ◽  
Central Basin ◽  
Time Data ◽  
The North ◽  
Travel Time Data ◽  
Seismic Swarms ◽  
Seismicity Catalog

<p>A massive template-matching approach is successfully applied in Marmara Sea region along  the North Anatolian Fault, during the 2009-2014 period to enrich the description of the time and space evolution of the seismicity. Detection of events are performed on the continuous data recorded from 2009 to 2014 combining two types of catalogs as templates: a finely constructed catalog for the three first year (2009-2011) (Schmittbuhl et al, 2016) and a raw catalog from KOERI for the last three years (2012-2014).  Magnitudes (Ml) are estimated for all detected events using relative amplitudes of the highly coherent waveforms between new events and template events. The template database provides a nearly threefold increase of the number of small events (more than 15000 earthquakes compare to the 4673 events of the initial catalog). Combined with a double-difference relocation based on cross-correlation differential travel-time data, the database is shown to be a relevant framework for the long term monitoring of specific remanent structures like seismic swarms or repeating earthquakes. The obtained catalog confirms the strong contrast of behaviors along the Main Marmara Fault (MMF): deep creeping to the west (Central Basin), fully locked in the center (Kumburgaz Basin) and dominated by fluid and off-fault activity to the east (Cinarcik Basin).</p>

Preliminary results of the study on the reasons of the Hai Hau erosion phenomenon

2007 ◽  
Vol 29 (3) ◽  
pp. 415-426
Author(s):  
Pham Van Ninh ◽  
Phan Ngoc Vinh ◽  
Nguyen Manh Hung ◽  
Dinh Van Manh
Keyword(s):  
Mathematical Modeling ◽  
Historical Data ◽  
Middle Part ◽  
Red River ◽  
Erosion Process ◽  
Red River Delta ◽  
The North ◽  
Severe Erosion ◽  
North And South ◽  
Very High

Overall the evolution process of the Red River Delta based on the maps and historical data resulted in a fact that before the 20th century all the Nam Dinh coastline was attributed to accumulation. Then started the erosion process at Xuan Thuydistrict and from the period of 1935 - 1965 the most severe erosion was contributed in the stretch from Ha Lan to Hai Trieu, 1965 - 1990 in Hai Chinh - Hai Hoa, 1990 - 2005 in the middle part of Hai Chinh - Hai Thinh (Hai Hau district). The adjoining stretches were suffered from not severe erosion. At the same time, the Ba Lat mouth is advanced to the sea and to the North and South direction by the time with a very high rate.The first task of the mathematical modeling of coastal line evolution of Hai Hau is to evaluate this important historical marked periods e. g. to model the coastal line at the periods before 1900, 1935 - 1965; 1965 - 1990; 1990 - 2005. The tasks is very complicated and time and working labors consuming.In the paper, the primarily results of the above mentioned simulations (as waves, currents, sediments transports and bottom - coastal lines evolution) has been shown. Based on the obtained results, there is a strong correlation between the protrusion magnitude and the southward moving of the erosion areas.

Studies of Ptiliidae (Coleoptera) in the Spirit Collection of the Natural History Museum, London 2: New species and records from P. Hammond's visit to New Zealand in 1983–84

2018 ◽  
Vol 154 (3) ◽  
pp. 179-196
Author(s):  
Michael Darby
Keyword(s):  
New Species ◽  
New Zealand ◽  
Natural History ◽  
Natural History Museum ◽  
History Museum ◽  
The North ◽  
Three New Species ◽  
North And South

Some 2,000 Ptiliidae collected in the North and South Islands of New Zealand in 1983/1984 by Peter Hammond of the Natural History Museum, London, are determined to 34 species, four of which are new to the country. As there are very few previous records, most from the Auckland district of North Island, the Hammond collection provides much new distributional data. The three new species: Nellosana insperatus sp. n., Notoptenidium flavum sp. n., and Notoptenidium johnsoni sp. n., are described and figured; the genus Ptiliodes is moved from Acrotrichinae to Ptiliinae, and Ptenidium formicetorum Kraatz recorded as a new introduction. Information is provided to aid separation of the new species from those previously recorded.

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