History

A detailed history of the status and the equipping

 

Foundation

 

            The organization and the development of activities in the field of seismology in the Republic of Macedonia have extensively been related to the development of the historic and political conditions in the Balkans.

The larger geographic region of Macedonia was the last of the Balkan territories that had been liberated from the Turks in 1912–1913. Until then, the seismological observation in Macedonia had been reduced to compilation of macroseismic data on felt strong earthquakes by the Turkish administration or individual foreign investigators, among whom Jelenko Mihailović from the Seismological Service of Serbia and Spas Vacov from the Central Meteorological Station in Sofia, Bulgaria.

After the Balkan Wars (1912–1913), a part of Macedonia, called by its geographical name of Vardar Macedonia, became a part of Serbia, and, after the World War I, a part of the Kingdom of the Serbs, Croats and Slovenians (named the Kingdom Yugoslavia in 1929). It was in 1913 that the Seismological Service of Serbia began to extend officially its activities in Vardar Macedonia.

            In 1944, Republic of Macedonia was established in the territory of VardarMacedonia as one of the six constituent republics of the Federal Republic of Yugoslavia. After the disintegration of this federal country, complete independence of Republic of Macedonia was proclaimed in 1991.

            In 1949, the Seismological Survey in Belgrade, which then acted as a Federal Yugoslav Seismological Survey, with Prof. Jelenko Mihailović (1869–1956) as its director, launched an initiative for establishment of several new seismological stations, among which was the one in Skopje. The necessary instruments were procured from abroad. Prof. Jelenko Mihailović, together with other experts, selected a location for the station in the Kisela Voda settlement in Skopje, over the northeast slopes of the VodnoMountain, on limestone of Paleozoicage, where the present seat building of the Seismological Observatory is. This initiative was not realized, since the Seismological Survey in Belgrade ceased to function as a Federal Seismological Yugoslav Survey, resuming its activities as Seismological Survey of Serbia.

            The establishment of seismological service in Republic of Macedonia was again on the agenda in 1953, again within the frameworks of the proposal for several new seismological stations in the territory of Federal Republic of Yugoslavia, given by the Federal Executive Council. The Executive Council of the Republic of Macedonia accepted the proposal. The construction of the station and the procurement of the equipment were entrusted to the Faculty of Philosophy in Skopje, exactly to its Department of Physics.

            In the beginning of 1954, the Faculty of Philosophy in Skopje sent Ordan Pečijare (a physicist) and Gigo Milevski (a geographer) to take over the formerly intended equipment for the seismological station in Skopje from the Seismological Survey of Serbia. On 29 June 1955, the University Council made a decision for establishment of the Seismological Station in Skopje, as an institution within the University of Skopje. The decision was accepted by the Executive Council and the Parliament of the Republic of Macedonia. The University Council appointed the geographer Gigo Mileski first acting director of the station. Soon, Gigo Milevski completed advanced training in seismology at the Seismological Survey of Serbia.

 

The building of the Seismological Station in Skopje in 1957

The building of the Seismological Station in Skopje in 1957. The location is on the northeast slopes of the mountain Vodno, in the Kisela Voda settlement.

 

            The first generation of seismological instrumentation,

          1957–1964: mechanical seismographs (Под-подрубрика 2)

 

Earlier in 1957, the building of the Seismological Station in Skopje (SKO) was completed at the location formerly selected by Prof. Jelenko Mihailović, which is, as said above, on the northeast slopes of the VodnoMountain in the Kisela Voda settlement in Skopje. Immediately afterwards, the first instruments, two middle‑period mechanical seismographs type MAINKA (EW and NS components, pendulum mass of 450 kg, registration with a needle over smoked paper put on a rotating drum, contact timing device WIECHERT), were mounted. The assemblage was done by Gigo Mileski, Vladimir Princ (from the Geophysical Institute at the Faculty of Natural Sciences and Mathematics of the University of Zagreb) and Dimitrije Traić (from the Seismological Survey of Serbia). It was with this equipment that the Seismological Station in Skopje started its activities on 1 July 1957. This is the date when publishing of results from seismological observations in seismological bulletins began, under the editorship of Gigo Milevski. In January 1960, Gigo Milevski went to work at the Geophysical Institute of the Faculty of Natural Sciences and Mathematics in Skopje. However, he served as honorary acting directorof the station up to 28 February 1961.

            On 1 March 1961, Dragan Hadžievski, graduated physicist from the Department of Physics at the Faculty of Natural Sciences and Mathematics in Skopje and graduated geophysicist from the Geophysical Institute at the Faculty of Natural Sciences and Mathematics in Zagreb, was appointed director of the Seismological Station in Skopje. Dragan Hadžievski carried out this function until 5 July 1988.

            Earlier in 1962, the University Council made a decision for establishment of a consultative board of the Seismological Station in Skopje. The first members of this board were: Miloš Pavlović (a geologist), the president of the board, Ordan Pečijare (a physicist), Josip Mozer (a physicist), Dušan Manaković (a geographer), Slavčo Bahčevandžiev (a physicist), all from the Faculty of Natural Sciences and Mathematics in Skopje, and Petar Miškovski, a jurist from the Secretariat for Internal Affairs of Republic of Macedonia.

On 15 February 1963, Dragan Hadžievski installed the middle-period mechanical seismograph type CONRAD (NS component, pendulum mass of 25 kg, registration with a needle over smoked paper put on a rotating drum). The seismograph was received from the Seismological Survey of Serbia in 1957.

 

The middle-period mechanical seismographs type MAINKAThe pendulum a cylindrical mass of 450 kg and the registration device a needle over smoked paper put on a rotating drum of one of the seismographs MAINKA

 (Left) The middle-period mechanical seismographs type MAINKA, NS and EW components (straight and on side), put in operation in the Seismological station in Skopje on 1 July 1957. (Right) The pendulum (a cylindrical mass of 450 kg) and the registration device (a needle over smoked paper put on a rotating drum) of one of the seismographs MAINKA.

 

The middle-period mechanical seismograph type CONRAD NS component put in operation in the Seismological station in Skopje on 15 February 1963

The middle-period mechanical seismograph type CONRAD, NS component, put in operation in the Seismological station in Skopje on 15 February 1963. The seismograph’s pendulum mass is 25 kg, and the registration is with needle over smoked paper put on a rotating drum.

 

            The strong earthquake of 26 July 1963 (04h 17min GMT, local magnitude 6.1) devastated the town of Skopje, damaged and put out of operation the seismographs at the seismological station. Dragan Hadžievski succeeded to put again into operation the CONRAD N-S component nearly 38 minutes after the beginning of the earthquake. His repairing of the MAINKA N-S component lasted nearly 2 hours and 32 minutes from the beginning of the earthquake. (The MAINKA E‑W component was heavily destroyed, and it was repaired after some days.) This enabled recording of the greatest number of aftershocks, and hence issuance of the seismological bulletin and reports. The latter were of a great importance for protection of the citizens.

 

The second generation of seismological instrumentation,

from 1964 to early 1990-ties: band-limited electromagnetic seismometers

with galvanometric registration on photo paper (Под-подрубрика 3)

 

The continuity of the instrumental monitoring enabled soon after the strong Skopje earthquake of 26 July 1963 gave the data-base for further seismological and seismotectonic investigations of the Skopje epicentral area.

           

A short-period electromagnetic seismometer type VEGIK constructed to reflect the ground motions in a horizontal direction

One of the stations installed in Skopje area during the joint project of the Institute for Physics of Solid Earth O. Yu. Shmidt from Moscow and the Seismological Station in Skopje

(Up) A short-period electromagnetic seismometer type VEGIK constructed to reflect the ground motions in a horizontal direction. (Down) One of the stations installed in Skopje area during the joint project of the Institute for Physics of Solid Earth “O. Yu. Shmidt” from Moscow and the Seismological Station in Skopje. The station is consisted of three short‑period electromagnetic seismometers type VEGIK, set in a way to reflect the ground motions along the vertical direction and the directions North–South and East–West.

 

A project for such investigations was prepared by the Seismological Station in Skopje in 1963, in cooperation with many Yugoslav seismological and geological institutions and UNESCO experts (Nicholas N. Ambraseys and others). The Seismological Station in Skopje and the Institute for Physics of Solid Earth “O. Yu. Shmidt” from the Academy of Sciences of USSR in Moscow (Russian abbr. IFZ) were chosen to perform the project. The members of the joint team were: D. N. Rustanovič (a supervisor, from IFZ), E. A. Koridalin (a consultant, from IFZ), S. V. Medvedev (a consultant, from IFZ), V. A. Tokmakov (a consultant, from IFZ) and D. Hadžievski (a consultant, from the Seismological Station in Skopje). Ten modern seismological stations, consisted of short‑period electromagnetic seismometers type VEGIK, GSH, VSH and VBP-3 with galvanometric analog registration on photo paper (all made in USSR), were provided by IFZ. Funding for the work of the team was provided by the Directorate for Reconstruction of Skopje, via the Geological Survey of Macedonia (Skopje).

The joint team started its regular work on 12 April 1964. The ten local seismological stations were installed in the seat building of the Seismological Station in Skopje, at five sites in the town of Skopje and in the surrounding villages of Matka, Brazda, Lipkovo and Katlanovo. Periodically, some other experts from the Yugoslav seismological and geophysical institutions took part in the working of the team. These were Josip Mokrović, Dragutin Skoko and Dragutin Cvijanović (from the Geophysical Institute at the Faculty of Natural Sciences and Mathematics in Zagreb, Croatia), Vladimir Ribarić (from the Geophysical Institute of the University in Ljubljana, Slovenia), Miloš Janković (from the Seismological Survey of Bosnia and Herzegovina), Slavko Vucinić and Nikola Jovicević (from the Seismological Survey of Monte Negro). Other participants were 40 laboratory technicians. These were the students Andjelka Milošević, Beatriče Force and Ivo Vukšić from the Geophysical Institute at the Faculty of Natural Sciences and Mathematics in Zagreb, and, further, students from the Department of Physics at the Faculty of Natural Sciences and Mathematics in Skopje, as well as from other faculties in Skopje. Two of the students from the Department of Physics at the Faculty of Natural Sciences and Mathematics in Skopje, Simeon Ordev and Nikola Vasilevski, showed a special interest in seismology, which was the reason for their permanent employment at the Seismological Station in Skopje.

   Nicholas N. Ambraseys(клик за линковите http://cires.colorado.edu/~bilham/Ambraseys.html и http://cires.colorado.edu/~bilham/NicksPubs/Ambraseys%20photosSkopje.html), then an expert of UNESCO in engineering seismology, and, later a world-known scientist in this field, visited the Seismological Station in Skopje during the work of the joint team, namely in 1964. (Ambraseys used to keep his contacts with the Seismological Station in Skopje until his death, in 2012. His last visit to the station was in February 1999, when he cameto Skopjeforraising the Skopje City prize13 November” (in the category ofinternationalcooperation)for 1998. He got this prize forhisrolein therebuildingof Skopje after the devastatingearthquakefrom 26 July 1963.)

In that way, the Seismological Station in Skopje became a centre in which most advanced methods of seismological observation, scientific interpretation and practical implementation of seismological data were employed. At the same time, the station was a school for new seismologists.

The joint project of the Institute for Physics of Solid Earth “O. Yu. Shmidt” from Moscow and the Seismological Station in Skopje yielded important results on the main parameters and source of the 26 July 1963 Skopje earthquake, the seismicity and the seismotectonics of the Skopje area. The Seismic Microzoning Map of the City of Skopje made during the project was further used as a basis for elaboration of the urban plan of the city. Many of these results were included in the periodical publications of the station, which started to be issued from 1965.

The work of the USSR seismologists was completed on 21 April 1965. The Seismological Station in Skopje bought the ten new-installed stations with financial support from the Directorate for Reconstruction of Skopje, and independently resumed the activities related to these stations.

 

      Sketch of the building of the Seismological station in Valandovo designer  the graduated architect Janko Konstantinov Skopje 1965

The station was put into operation on 16 February 1966

Sketch of the building of the Seismological station in Valandovo (designer – the graduated architect Janko Konstantinov, Skopje, 1965), and a photo of a part of the building taken in July 2013. The station was put into operation on 16 February 1966.

 

The buildings of the Seismological station in Ohrid. The location is in the area Varoš near the church of St. Caneo. The station was put into operation on 9 September 1967 2

The buildings of the Seismological station in Ohrid. The location is in the area Varoš near the church of St. Caneo. The station was put into operation on 9 September 1967

The buildings of the Seismological station in Ohrid. The location is in the area Varoš, near the church of St. Caneo. The station was put into operation on 9 September 1967.

 

            In December 1964, the station in Skopje started an upgrading of the seismological service by procurement of additional equipment. One part of the new equipment (beside the set of three short‑period electromagnetic seismometers type WILLMORE, the STRONG-MOTION RECORDER AR-240 and other sensors), were the set of three short‑period electromagnetic seismometers type LEHNER-GRIFFITH and the set of three long-period electromagnetic seismometers type PRESS-EWING. (Installed with galvanometric analog registration on photo paper, they will operate up to the early 1990-ties.) At the same time, the reconstruction of the building of the station in Skopje and the construction of two new seismological stations in Valandovo and Ohrid started. Two sets of three LEHNER-GRIFFITH seismometers with galvanometric analog registration on photo paper were provided for the stations in Ohrid and Valandovo. The UN Special Fund provided the necessary resources for all these actions.

In addition to the engagement of the whole staff of the Seismological Station in Skopje, valuable scientific and professional assistance was also provided by D. Skoko from the Geophysical Institute at the Faculty of Natural Sciences and Mathematics in Zagreb, N. V. Shebalin from IFZ in Moscow (then expert of UNESCO in Skopje) and M. McElheny from the United Electrodynamics (Earth Science Division, Inc.), Pasadena, California, USA. The later company was the supplier of the entire new seismological equipment.

            The new equipment of the Seismological Station in Skopje was put into operation on 14 March 1966. The seismological station in Valandovo (VAY) began working on 16 February 1966, whereas that in Ohrid (OHR) started on 9 September 1967.

 

      The vertical components of the short period electromagnetic seismometer LEHNER-GRIFFITH and long period electromagnetic seismometerPRESS-EWING in the seat building of the Seismological Observatory in Skopje

The vertical components of the short‑period electromagnetic seismometer LEHNER-GRIFFITH and long‑period electromagnetic seismometer PRESS-EWING in the seat building of the Seismological Observatory in Skopje. (The both seismometers are made in USA.)

 

An aquarelle of the seat building of the Seismological Observatory in Skopje from 1966

An aquarelle of the seat building of the Seismological Observatory in Skopje from 1966

 

The intensified activities of the Seismological Station in Skopje imposed its reorganization. In 1966, it became a Seismological Observatory within the University of Skopje.

 

One of the middle-period elecromagnetic seismometers SKD USSR production purchased by the Seismological Observatory in Skopje in 1974

One of the middle-period elecromagnetic seismometers SKD (USSR production) purchased by the Seismological Observatory in Skopje in 1974. The shown seismometer is installed in the seat building of the Seismological Observatory in Skopje in a way to reflect the ground motions along the direction East–West (SKD E–W component).

 

One of the analog recorders type VR 1 Kinemetrics Inc. USA purchased by the Seismological Observatory in Skopje in the middle 1970-ties

One of the analog recorders type VR‑1 (Kinemetrics Inc., USA) purchased by the Seismological Observatory in Skopje in the middle 1970-ties.

 

            During the 1960-ties and 1970-ties, the Seismological Observatory in Skopje performed instrumental observations and investigations of seismicity also of epicentral areas beyond Republic of Macedonia: Leskovac area (Serbia) in the period 1 June 1967 till 15 December 1968, by three own seismological stations; Banja Luka area (Bosnia and Herzegovina), after the strong earthquake occurred there on 27 October 1969 (in fact, from 29 October 1969 till 31 May 1971), with five seismological stations, jointly with the Institute of Earthquake Engineering and Engineering Seismology (IZIIS) from Skopje; in the Montenegrin coastal area, after the strong earthquake occurred there on 15 April 1979 (in fact, from 10 May 1979 till 10 October 1979), by two seismological stations.

In the period 1970–1976, the Seismological Observatory in Skopje participated in the international UNDP/UNESCO scientific-research project on investigation of the seismicity of the Balkans. The main office of the project was in Skopje. The cooperation with world-known seismologists and experts of UNESCO (V. Karnik, T. S. Algermissen, N. V. Shebalin, A. R. Ritsema, V. V. Belousov, C. R. Allen, L. Christoskov, J. Drakopoulos, C. Radu and others) within this project led to a considerable progress of the оbservatory. The Editor-in-Chief of the project, the world-known seismologist Vit Karnik (one of the authors of the famous MSK-64 macroseismic scale), stayed in Skopje the longest time, with accommodation in the building of the observatory. (In that time, Vit Karnik was employed in the Geophysical Institute of the Czechoslovak Academy of Sciences, Prague). During this project, in 1974, the Observatory installed a set of three middle-period electromagnetic seismograph SKD with galvanometric analog registration on photo paper (made in USSR), as well as an electromagnetic accelerograph type OSB-I MP with galvanometric analog registration on photo paper (an USSR make). At the same time, the observatory also procured three analog recorders type VR-1, which use a needle with ink over white paper put on a rotating drum (a product of Kinemetrics Inc., Pasadena, California).

 

The seismological station at the seat building of the Seismological Observatory in Skopje

PRESS EWING long period and SKD middle period used from the middle 1960-ties up to the early 1990-ties with galvanometric analog registration on photo paper

The seismological station at the seatbuilding of the Seismological Observatory in Skopje: (up) the band-limited electromagnetic seismometers LEHNERGRIFFITH(short‑period), PRESS‑EWING (long‑period) and SKD (middle‑period), used from the middle 1960-ties up to the early 1990-ties with galvanometric analog registration on photo paper (down).

 

In the period 1970 to 1974, the Seismological Observatory in Skopje elaborated the scientific-research project Seismic Zoning of the Territory of SR Macedonia, together with the Institute of Earthquake Engineering and Engineering Seismology and the Department of Geotechnicsat the Faculty for Civil Engineering. For the needs of this project, six temporary seismological stations (equipped with sets of short‑period electromagnetic seismometers type VEGIK with galvanometric analog registration on photo paper) were installed in the towns of Veles and Star Dojran, and at the dams of Kežovica (near the town of Štip), Došnica (near the town of Demir Kapija), Turija (near the town of Strumica) and Tikveš (near the town of Kavadarci). A very important result from this project is the Seismic Zoning Map of Macedonia.

             The above two projects clearly pointed out the need for installation of a denser network of permanent seismological stations in the territory of Republic of Macedonia. Since then, a number of programmes referring to this problem have been developed at the Seismological Observatory in Skopje.

On 11 May 1976, the Seismological Observatory in Skopje became a member of the Skopje University Centre for Mathematical and Technical Sciences. On 14 June 1976, the Seismological Observatory in Skopje joined the Faculty of Physics in Skopje, the later being also a member of the mentioned centre. On 12 December 1984, the Faculty of Natural Sciences and Mathematics in Skopje was again established, and the observatory became one of its institutes.

           

 

 

The third generation of seismological instrumentation,

from early 1990-ties up to nowadays: modern band-limited, wide-range

and broad-band electromagnetic seismometers with digital registration (Под-подрубрика 4)

 

Following the new worldwide trends of development of instrumental seismology, the Seismological Observatory in Skopje undertook many activities. It succeeded to be included in the UNDP project Development and installation of telemetred and computerized seismic stations network in SR Macedonia. In connectionwiththis project, LazoPekevski, then a Master ofPhysical Sciencesand an assistantinthe observatory, performed a specialization intheUS Geological Survey – USGS,inGolden, Colorado.

In 1986, the observatory submitted to the Parliament of the Republic of Macedonia a five-year Programme for Development of Seismological Service in SRM. This programmeincluded the Programme for Installation of a Telemetric Network of Seismological Stations in Macedonia. It was planned to equip the existing three seismological stations (Skopje, Valandovo and Ohrid) with new seismometers and digital recorders, and to open new telemetric stations, all connected into a network with computer acquisition and processing of seismological data.

According to an intervention law on retirement, Prof. Dragan Hadžievski, the Head of the observatory, was prematurelyretired on 5 July 1988. From then until 30 September 1989, the acting Head of the observatory is Lazo Pekevski. On 1 October 1989, Ljube Milenkovski, a Doctor of Geographical Sciences and an Associate Professor in the Institute of Geography at the Faculty of Natural Sciences and Mathematics in Skopje, was appointed Head of the observatory. On 9 July 1993, Ljupčo Jordanovski, a Doctor of Civil Engineering and Engineering Seismology, then an Associate Research Professor at the observatory, was appointed Head of the observatory.

Accepting the aforementioned Programme for Installation of a Telemetric Network of Seismological Stations in Macedonia, the Parliament of the Republic of Macedonia allowed funding for the purchase of new seismological and computer equipment. According to a project which was led by Lazo Pekevski, these funds were partly realized in 1991, when sets consisted of three short‑period electromagnetic seismometers type SS‑1 and a digital recorder type SSR‑1 (all products of Kinemetrics Inc., USA) were acquired for the seismological stations in Skopje, Ohrid and Valandovo. The installation in the seat building of the observatory in Skopje was done during March 1991, in the station in Ohrid – on 12 March 1994, and in the station in Valandovo – on 23 March 1994. The exchange of digital seismological data among these stations was realized by a modem, via telephone connections. The centre of data acquisition and analysis was set at the seat building of the Seismological Observatory in Skopje.

Thus, 23 March 1994 is the day of putting into operation of the first telemetric seismological network in the Republic of Macedonia. For some period of time, the later network operated simultaneously with the former network of analog seismological stations.

During the realization of the scientific-research project PLATO, the project partners, the Institute of Earthquake Engineering and Engineering Seismology from Skopje and the National Institute for Geophysics and Vulcanology (INGV) from Italy, cooperated with the Seismological Observatory in Skopje. As a result, a new integrated network of analog and telemetrically connected digital seismological stations was established in Republic of Macedonia. The Seismological Observatory in Skopje obtained additional modern equipment. In 1996, the short-period electromagnetic seismometers type SS-1 RANGER at the stations in Skopje, Ohrid and Valandovo were replaced by wide-range electromagnetic seismometers type WR-1 RANGER (products of Kinemetrics Inc., USA). New telemetric digital stations, each consisted of three short-period electromagnetic seismometers type SS-1 RANGER and one digital recorder SSR‑1, were installed on the Streževo dam (near the town of Bitola), on the Ratevo dam (near the town of Berovo), in the towns of Bitola, Štip, Kriva Palanka and Debar, as well in the village of Gorno Vranovci (near the town of Veles). The data from the network was exchanged with a number of institutions, such as the Strong Motion Laboratory at Institute of Earthquake Engineering and Engineering Seismology in Skopje, the Seismological Network MEDNET of the INGV in Rome and the Euro-Mediterranean Seismological Centre (CSEM) in France. The feedback information on earthquakes that occur in the territory of the Republic of Macedonia enabled much faster and high-quality investigation of the earthquakes.

           

The modern short-period electromagnetic seismometers type SS 1 RANGER set in a way to reflect the ground motions along the vertical direction and the directions NorthSouth and EastWest

The modern short-period electromagnetic seismometers type SS‑1 RANGER, set in a way to reflect the ground motions along the vertical direction and the directions North–South and East–West. The seismometersof this type were for the first time purchased by the Seismological Observatory in Skopje from Kinemetrics Inc., USA, in 1991.

 

A wide-range electromagnetic seismometer type WR 1 RANGER production of Kinemetrics Inc. USA

Awide-range electromagnetic seismometer type WR‑1 RANGER (production of Kinemetrics Inc., USA). The seismometer contains, in fact, three wide-range electromagnetic seismometers, set in a way to reflect the ground motions along the vertical direction and two perpendicular horizontal directions. The Seismological Observatory in Skopje obtained three WR‑1 RANGER seismometers in 1996.

 

Due to some problems in the infrastructure, from all above mentioned stations, only the stations in Bitola, Štip and Kriva Palanka, were kept. The first two of these three stations are now permanent station in the telemetric network of Republic of Macedonia, while the station in Kriva Palanka operates as a temporary one.

           

The seat building of the Seismological Observatory in Skopje after its extension in 1998

The seat building of the Seismological Observatory in Skopje after its extension in 1998.

 

The acquiring of new equipment within the project PLATO released a part of the observatory’s finances approved previously (in 1990) by the Parliament of the Republic of Macedonia for the same purpose. The observatory made new efforts to obtain an additional budget from the Government for extension of the seat building and for upgrading the computer equipment. Thus, during 1998, with a large engagement of the Head of the observatory, Ljupčo Jordanovski, and of all other employees, an extension of the seat building of the observatory in Skopje was done. This provided additional separate offices and a room for every-day analysis of the seismological network data. Ljupčo Jordanovski was the Head of the observatory up to 9 March 2001. On 10 March 2001, this function was again assigned to Lazo Pekevski, then a Doctor of Natural Sciences and an Assistant Professor.

In 2003, a partial renovation of the seismological station in Ohrid was done using a budget obtained from the Government.

The project DIRECTE 2 (Development of Infrastructure for Rapid Earthquake Data Collection and Exchange), 2004–2005, whose leaders were Peter Labak from the Geophysical Institute of the Slovak Academy of Sciences, Bratislava, and Lazo Pekevski from the Seismological Observatory in Skopje, planned to enhance the capacity of the telemetric seismological network in Republic of Macedonia and to implement a real-time exchange of seismological data within this network, as well as with the telemetric seismological stations from abroad.,

Under this project, in 2005, with funding from UNESCO (namely from the programme Slovac Aid), the digital recorders type SSR-1 in the stations in Skopje, Ohrid, Valandovo, Bitola and Štip were replaced with digital recorders type Wave24. (Wave24, a product of the company MicroStep-MIS from Slovakia, is a seismological measuring system, which uses a 24-bit digitizer and has an appropriate data acquisition.) These stations were interlinked via Internet in a new telemetric network. Again via Internet, this network was linked with a number of seismological stations from the Balkans, which enabled a real-time exchange of seismological data. The central acquisition and processing of seismological data for the Republic of Macedonia was prescribed to seat building of the Seismological Observatory in Skopje, where new computer equipment was set and appropriate softwares in the operating system LINUX were installed. The software Seismic Handler was installed for data processing. Through the web-site of the observatory, the records of the seismological stations in Republic of Macedonia used to be available to the seismological institutions from around the world and to the public.

 

electromagnetic seismometers SS 1 short-period WR 1 wide-range period up and right the SSR 1 digital recorder

down and left the QuanterraQ330 digital recorderdown and right the Wave24 digital recorder and the obtained record on a computer monitor

Modern equipment of the seismological station at seatbuilding of the Seismological Observatory in Skopje. (Up and left) electromagnetic seismometers SS1 (short-period) and WR1 (wide-range period); (up and right) the SSR1 digital recorder; (down and left) the Quanterra–Q330 digital recorder; (down and right) the Wave24 digital recorder and the obtained record on a computer monitor.

 

All new equipment is officially put into operation on 3 February 2006. On 29 July 2006, in the town of Kruševo, at a temporary location, a digital seismological station, consisted of three SS‑1 seismometers and one Wave24 digital recorder, was installed. The station was also included in the above described exchange of seismic data in real time. In 2009, the Wave24 digital recorder at the station in Skopje was replaced with a Quantera-Q330 digital recorder (a product of Kinemetrics Inc., USA).

The described new increasing of the capacity of the telemetric seismological network in Republic of Macedonia provides detailed information on seismicity of the territory of the Republic and the surrounding areas. This has a direct impact on the precision in determining the seismic hazard, and, consequently, on the input data for relevant codes of construction of buildings. The internal and external real-time data exchange of the seismological network in the country allows obtaining fast and reliable data about the earthquakes. Thus, the readiness of the Republic of Macedonia for a case of strong earthquake is particularly increased, since the fast information about a strong earthquake enables also fast actions and measures for protection of the population.

 

The seismological station real-time digital data from the seismological stations The seismological station real-time digital data from the seismological stations and their analysis with the software Seismic Handler

The seismological station at the seatbuilding of the Seismological Observatory in Skopje: real-time digital data from the seismological stations in the Republic of Macedonia and the Balkans (left) and their analysis with the software Seismic Handler (right).

 

Lazo Pekevski performs the function Head of the observatory until 14 October 2007. On 15 September 2007, Ljupčo Jordanovski, then a Research Professor, was again appointed Head of the observatory. On 15 September 2009, Lazo Pekevski, then an Associate Professor, was again appointed Head of the observatory. Ljupčo Jordanovski died on 7 October 2010. Lazo Pekevski finished his Head’s mandate on 14 September 2011, when his University title was Research Professor. On 15 September 2011, Vera Čejkovska, a Doctor of Physical Sciences and, then an Assistant Professor,was appointed Head of the observatory (her present university title is Associate Research Professor).

The Ministry of Education and Science of the Republic of Macedonia, after the visit of the Minister Nikola Todorov to the observatory on 15 March 2011, provided funds for new equipment of the observatory. Thus, during 2011, five personal computers were received, and, at the end of the same year, two modern digital seismic stations, each consisting of a package EpiSensor-Model FBA ES-T and a digital recorder type Quantera-Q330HRS (products of Kinemetrics Inc, USA) were purchased. Each package EpiSensor–Model FBA ES-T consists of three broadband seismic sensors / accelerometers EpiSensor, which reflect the ground motions movement along the vertical direction and two horizontal directions.

The observatory plans to install the new seismic stations at locations in the town of Debar and in the Delčevo-Berovo area. Unfortunately, due to very unfavorable financial situation of the observatory, driven by the continued reduction of the budget for the seismological service, these installations can not be realized soon.

According to an application project for monitoring of the regular and induced seismicity in the area around the accumulation for the Kozjak dam (the municipality of Makedonski Brod) in the period 2004–2008, the observatory maintained in 2003–2008three digital seismic stations, owned by the Macedonian Power Plants Inc. The locations of the stations were at the Kozjak dam and in the villages of Samokov and Belica. The monitoring at these stations continued, in fact, also during the period 2009–2011, at it was reported to the Macedonian Power Plants Inc.

According to a new application project for monitoring of the regular and induced seismicity in the areas around the accumulations for the Kozjakdam (the municipality of Makedonski Brod) and St. Petka dam (near the town of Skopje) in the period 2012-2014, the observatory has been maintainingthree digital seismic stations, two of which (at the Kozjak and St. Petka dams) are owned by Macedonian Power Plants Inc., and one is owned by the observatory itself.

 

           

One of the two packages EpiSensor-Model FBA ES-T

One of the two packages EpiSensorModel FBA ES-T provided for the Seismological Observatory in Skopje by the Ministry of Education and Science of the Republic of Macedonia in 2011.

 

The two digital recorders QuanteraQ330HRS provided for the Seismological Observatory in Skopje by the Ministry of Education and Science of the Republic of Macedonia in 2011

The two digital recorders Quantera–Q330HRS provided for the Seismological Observatory in Skopje by the Ministry of Education and Science of the Republic of Macedoniain 2011.

 

In 2010, within an application project for seismic monitoring of the area around the accumulation for the Lisiče dam (near the town of Veles), the observatory maintained its own seismological station at the dam.

According to an application project for monitoring of the regular and induced seismicity in the area around the accumulation for the Kneževo dam (hydrosystem “Zletovica”, near the town of Probištip) from October 2012 to October 2013, the observatory has been maintaining its own digital seismic station at the Kneževo dam.