Qatar Seismic Network

About Qatar Seismic Network

Introduction

Earthquakes are a very complex natural phenomenon occurring in the deep earth's lithosphere (its crust and upper mantle). The earthquake appears as a series of vibrations induced in the earth's lithosphere by abrupt rupture and sudden release of built-up stress (energy) within rocks along geologic faults or by the movement of magma in volcanic areas. The sudden release of energy causes the seismic waves which pass through the earth’s rocks and make the ground shake. Earthquake-like seismic waves can also be caused by underground explosions. Sometimes seismic waves occur when the roof or walls of a mine collapse. The probability of occurrence of an earthquake at a site depends on a number of factors; the geologic setting and seismic history constitute the most important factors.

The tectonic style of the Qatar peninsula is essentially gentle and quite simple. But, the Qatar Peninsula is located within the Arabian Plate which is characterized by active seismic edges. It is located southwest of the active collision plate boundary between the Arabian and Asian (Iranian) Plates (Zagros Fold Belt). Earthquakes of Zagros Belt may pose a significant hazard to tall buildings in Qatar.

Economically, Qatar is one of the main oil and gas producers worldwide and it has intensive production activity. As a result, Qatar has wealth and great economic revolution. Qatar’s recent rapid economic growth is led by its oil and gas industry, as well as other industries. Recently, much major industrial and urban developments have been built in Qatar and major advances in economic, human and social developments continue to occur. Oil and gas production can cause earthquakes. Those earthquakes can create negative impact to such developments. The Qatar National Vision 2030 aims to create a sustainable economy and advance the standard of living of its people. Therefore, Qatar shows extensive interest for earthquakes studies to reduce their risks and to take advantage of their occurrence. From this perspective and on the basis of the Qatar National Research Strategy, the Qatar Meteorological Department (QMET) of Civil Aviation Authority (CAA) initiated to establish Qatar Seismic Network (QSN) to constitute the first step towards the establishment of Qatar Seismic Information Center (QSIC). The necessary studies for the establishment of QSIC were started in 2012 aiming to provide it with the up-to-date technology in the field of seismology and geophysics and to achieve the aspirations of the state and work to achieve the following objectives:-

1. Assessment seismic risks in Qatar and coordination with the competent authorities to reduce those risks.

2. Providing information on the geophysical properties for the areas of seismic activity.

3. Building a database of seismic activity for scientific research purposes.

4. Providing technical consultancy to the concerned authorities in the field of geophysics, and seismology.

5. Relating geophysics research studies with the overall development plans and with the future community vision.

6. Sharing in the world seismic activity studies, especially at the level of the Arab countries.

7. Execute related theoretical and practical research studies and participating in projects of national importance.

8. Support the scientific and technical cooperation and exchange of experiences with universities, scientific institutions and stakeholders in all countries, especially the nations of Gulf Cooperation Council (GCC).

9. Transfer and localization advanced technologies to cope with disasters and environmental crises.

10. Participation in community service and development through direct and continuous interaction with its economic, social and cultural institutions.

11. Cooperate with concerned authorities to establish seismic buildings codes.

12. Contract, and implement contracts for seismic activity with government agencies, companies and relevant international bodies.

13. Create a cadre of qualified national manpower in the field of seismology.

14. Hold training courses, workshops and conferences specialized in seismology and geophysics.

15. Participation in international conferences, seminars and workshops of seismology and geophysics.

 

Qatar Seismic Network

Historically, QMET established four analog seismic stations in 1990 which were stopped in 2004. Each of these stations was consisted of single component short-period sensor. The locations of those stations are not installed according to any geological or tectonic activity, and no site tests were made. At the beginning of 2013, and after the great development in instruments, QMET worked on the establishment of Qatar Seismic Network (QSN). In December 2013, the installation of QSN stations was started and the experimental operation of the network started in June 2014. The QSN has been designed to cover the largest possible area of Qatar including the main tectonic structure of the country. The network was designed to:

1. Monitor and process the seismic activities in the State of Qatar and in the world (local, regional and teleseismic events).

2. Characterize seismicity in the State of Qatar.

3. Proceed with necessary studies and research concerned with seismology.

4. Map seismic activity of Qatar and neighboring countries.

5. Create immediate report for events of importance to government agencies and the media.

6. Cooperate with international centers in the field of seismology (e.g. data exchange).

7. Accommodate the future network expansion.

 

The Design of Qatar Seismic Network

Currently, the network consists of six seismic field stations and receiving center for data archiving and processing. The QSN was designed with and provided with the most up-to-date international techniques in the field of seismography. Its field stations distributed all over Qatar according to the tectonic setting of the State. Three of these stations are short-period stations and three are broadband stations. Moreover, each of these stations is equipped by accelerometer for strong motion recording.

Each field station has mainly 3 parts. The first part is the observer unit, which includes one accelerometer (EpiSensor FBA ES-T) and one seismometer. The seismometer of short-period stations is SS-1 Ranger and the seismometer of broadband stations is Metrozet PBB-200S. Seismometers and accelerometers are placed on a solid, leveled surface in a 2.0 to 3.0 meters deep seismic vault.

The second part is the recording and digitizing unit which amplifies, digitizes and records the observed data. QSN is using the Quanterra Q330S+ (6-channels) for recording, digitizing and amplifying the observed data. The third unit is the communication unit which includes 3G modem (Sierra Wireless - LS300) connecting the station to the internet and the data is transferred to QSN main data server through a secured A Virtual Private Network (VPN) connection. Accordingly, QSN is a real-time telemetric full duplex seismic network. The filed stations are powered by batteries, which are charged through solar cells to supply continuous power.

Each seismometer converts the earth’s vibrations into an electrical current that is proportional to the amplitude of these vibrations. That current is digitized and amplified in the field into a digital value with precise sampling by the Quanterra Q330S+ which continuously send these data through the communication unit to the recording/analysis center at QMET in Abu Hamour area. Time signals (Universal Time signal) are added in the field by special devices connected to satellites.



Recording and Analysis Center

The QSN center in QMET remotely controls all field stations and receives the transmitted data from all the stations on the main server of the network. The center is equipped with GPS Receiver/Clock for accurate Universal Time to accomplish sampling synchronously, so that all data samples in the network are time-aligned.

Automatically and in continuous way (in real-time), the occurrence of any seismic wave is received, displayed and recorded by using up-to-date software (Antelope Software Package). Antelope software is installed to perform the tasks of data acquisition, buffering, back-up archiving, events' detection, analyses and declaration. The installed software enables the network operators to control the network, including field stations digitizer parameter setup and state-of-health information retrieval. In addition, the software has the ability to receive seismic waves on a continuous basis from international seismic stations and networks.

The devices and software of QSN center were selected and designed to have the ability to accommodate future increase in the number of field stations. In addition, the center was equipped with two big screens to display the instantaneous movement of the earth.

When an abnormal seismic wave is detected the event is auto-picked and analyzed. Afterward, seismologists review the analyzed events for reporting. All received data (raw data) and the analyzed events are stored in the QSN database server.

 

Earthquake Activities in the State of Qatar before QSN

Historical documents have never mentioned any significant earthquakes within the State of Qatar. Regional and international earthquake centers have recorded a number of small to medium magnitude earthquakes in and around Qatar. The only earthquake which occurred in Qatar and was large enough to be detected by international networks was in 1929. That earthquake was occurred with magnitude of 4.7 and located south of Doha city.

Moreover, the QMET stations which were worked in the period from 1990 to 2004 recorded some local earthquakes (within the Arabian Gulf) of small magnitude (M ≤ 3.7). Recently, the international and regional observatories recorded many strong earthquakes that were occurred faraway from Qatar but were felted in Qatar. The earthquake of Iran-Pakistan border (April 16, 2013) is one of the most important earthquakes that occurred outside Qatar and felt within Qatar. The epicenter of that earthquake was about 1,100 kilometers from Doha. This quake happened at: 13:44 pm (Doha Time), with magnitude of 7.8 and depth of 87 km. It was felt by the residents in Qatar especially who were in the upper floors of towers in Al-Dafna area. This earthquake was strong enough to pose terrified, panic, and forcing people to escape out into the streets fearing on their lives.

Qatar Civil Aviation Authority

Meteorological Department

Earthquakes Unit

P.O. Box: 3000

Al-Doha – Qatar

Fax: +974 44557004

Tel: +974 44551623