Rezultaty
Field observations included quantitative geomorphology with measurements of past displacements and structural analysis of fault zones that revealed a clear fault segmentation. The correlation between fault segments and macroseismic zones of historical earthquakes (as obtained from the APAME seismicity catalogue) documents the precise location of past earthquake ruptures. Paleoseismic and archeoseismic investigations in Turkey (along the DSF and at Sicantarla Tell site), in Syria (at 3 sites along the Missyaf segment of the DSF), in Lebanon (along the Yammouneh Fault, the Roum Fault, the Serghaya Fault and Rachaya Fault) and in Jordan (at the Karameh and Tell Assaydiyeh along the Jordan Valley) provide the seismic parameters necessary to assess the size of past earthquakes. Detailed topographic profiles and DEM were achieved for each paleoseismic and archeoseismic site (Deliverable D4).
The paleoseismology and archeoseismology approaches (Deliverable D5) clearly contribute to the extension of seismicity catalogues in the past, which covers now in some regions such as the DSF in Turkey and along the Jordan Valley several seismic cycles (> 20 000 years of large earthquakes catalogue). On the other hand, the Paleoseismology of the Al Harif Roman Aqueduct included a detailed study of cores in travertines and showed results consistent with the trenching and excavation that revealed the occurrence of 3 major seismic events in the last 2000 years (among them the AD 1170, Deliverables D5 and D6).
Geophysical and geodetic (GPS) investigations were also conducted at different sites along the fault zones and archaeological sites. The ground penetrating radar (GPR) and magnetic prospecting at the Sicantarla Tell in Turkey displayed ~ 40m of left-lateral offset along the DSF which constitutes a real archive on the occurrence of successive earthquakes since 6500BC. Similarly, the GPR and high-resolution seismic profiles along the Jordan Valley (at Al Karameh-Ghor Kabed pull apart) revealed the extent of the fault zone and related cumulative offsets related with past earthquakes. On the other hand, collaboration with TUBITAK (National Research Centre in Turkey) and the MIT (Boston) allowed the installation of a dense GPS network of 22 (campaign) stations at the junction between the DSF and EAF in the Hatay region in Turkey.
The 2004 campaign measurements at the junction (combined with results of previous campaigns since 1991) characterized the slip rate along the EAF (9.2mm/yr.) along the Karasu Valley fault (4.1 mm/yr.) and along the DSF (6.2mm/yr.). These results are an important contribution to the identification of active with earthquake slip deficit and the potential for future large earthquakes at the junction.
Partner 3 (ICSTM London) took in charge the historical and instrumental reappraisal of a parametric seismicity catalogue and seismic event locations in cooperation with Partner 1 (IPG Strasbourg), Partner 4 (DGAM Syria), Partner 7 (Ujordan) and Partner 8 (OGU, Turkey). Among the most striking results, the seismicity catalogue published by Sbeinati and colleagues (Partner 4) provide with valuable dataset on the moderate-sized and large earthquakes occurrence with damage distribution and location of the northern segments of the Dead Sea fault zone. Specific studies and the 3 publications of Ambraseys (Partner 3) on the middle of the 8th century seismicity in Syria and Palestine (with special attention to historical earthquakes in Jerusalem) and on the 12th century seismic paroxysm in the Middle East contribute to significantly enhance the seismicity catalogue. The new parametric catalogue compiled by the APAME working group (see also the list in Deliverable D1) indicates that the level of uncertainty of the location of large historical earthquakes is good enough to guide field studies for further investigation.
The preparation of the parametric seismicity catalogue consisted in:
- Specific studies on newly discovered historical earthquakes from original documents,
- Critical evaluation of major historical earthquakes and reappraisal from new documents,
- Critical evaluation of the seismic activity of the DSFZ before our era, based on archaeological and paleoseismological information,
- The uniform re-evaluation of seismicity of the study region for the period before 2000.
- Magnitude assessment of the size (Msm) of historical events.
- Derivation of frequency-magnitude recurrence relations for the assessment of earthquake hazard in the study region and in the DSFZ.
- Assessment of the slip rate of the DSFZ
The APAME project drained interests from a large part of the scientific community, including historians, archaeologists, seismologists, geophysicists, earthquake geologists, sociologists and local authorities of the studied regions. The APAME project benefits from a Web site at http://apamea.u-strasbg.fr/ since early months of the project where a Member site is devoted to the exchange of data and results in between partners.
The dissemination strategy was built following three steps:
1) toward the local authorities and scientists that could benefit from the recent field investigations and results immediately applicable to the seismic hazard assessment;
2) toward a large component of the scientific community and therefore, large international meetings as the European Geophysical Union (EGU) or the American Geophysical Union (AGU) were our preferable targets; and
3) small meetings and workshops with specific topics dedicated to the seismic hazard and preservation of cultural heritage and archaeological sites.
In parallel, the consortium presented the project and its main results to different institutions in Turkey (the municipality and civil engineering association of Antachia), in Syria (to the Ministry of Culture and University of Damascus and Aleppo) and in Jordan (to the local association in engineering geology and Ministry of Natural Resources and to the Civil Protection). Press conferences were also organised in Turkey and Jordan.
The different work packages and large amount of field investigations and related results requires a certain elapsed time for the preparation of publications. Even well after the end of the project (in August 2006) the APAME consortium aims at a further meeting and seeks for organizing a special conference where the results could be presented and discussed. The conference is in preparation for 2008. However, more than 10 papers with reference to the APAME Project were published in standard international and peer-reviewed scientific journals (see also the list below). At least other 10 publications are in preparation and a special volume in a scientific collection (Springer) is planned.
Although a large amount of paleoseismic and archaeoseismic data were collected and important results on the long term behaviour of seismogenic faults and related return period were provided in APAME, the absence of critical seismological data (seismometer and accelerometer recordings) prevented us to construct a robust seismic hazard analysis and map of the DSF for engineering purposes. An attempt has been made for Lebanon and previous studies provide some scenarios of seismic hazard assessment. However, a definitive parametric seismic catalogue is needed that covers S.E. Turkey, Syria, Lebanon, Israel, Palestine and Jordan, with all precise locations and magnitudes of historical and instrumental seismic events. Recent earthquakes should provide important results on the velocity structures, crustal behaviour at depth and surface and rate of active deformation along the DSF. Also, we need to know the frequency-magnitude distribution (f-m), not only within the region covered by the APAME project, but also in the different tectonic sub-regions. This information is not available. One has to note that the (f-m) distribution for the DSF is discontinuous in time, involving long periods of relative quiescence.
This is a typical feature of the DSF, which cannot be ignored. A collaboration with the Lebanese American University allowed to test and model earthquake damage to columns of Baalbek (Jupiter Temple) and other building structures. The approach consists on the use of state of the art numerical modelling to predict the effect of earthquake damage on large masonry structures. The model needed earthquake loading and a source-rupture/time history of ground motion and acceleration. The reference earthquake is the Gulf of Aqaba earthquake of November 22, 1995 (epicenter 28.76N, 34.66E, focal depth 12km, Ms= 6.2). The Peak ground accelerations 0.109g updown, 0.097g E-W, and 0.086g N-S. The modelling clearly predicts the beam characteristics of the different blocks.
Also the DSF long-term (f-m) distribution is strongly non-linear as well as clustered in space and time. So far as we know there are no non-linear hazard mapping programmes at present readily available to account for these conditions. On the other hand, this project provides evidence of past seismic hazard through archeo-paleoseismic studies that would contribute to our knowledge. Moreover, an important observation is the total lack of a region-specific ground motion attenuation law. Any attempt to produce a hazard map, glossing over all these difficulties for the sake of convenience, and to over-simplify the model, is likely to produce fictitious results, which will be not only unscientific but also misleading for the end-user.
A large number of documents, maps, tables, and publications are produced by the APAME consortium.
The GIS is implemented using MAPINFO and will charge the following documents:
- Maps, reports and publications.
- Revised historical catalogue in both electronic and printed form.
- Oral and Poster presentations during scientific and public meetings and seminars.
- Direct access to the APAME Project Web-site, where main project achievements and results will be visible to professionals and large audience.
- Since the Geographic Information System (GIS) and website will remain in activity for the coming years, some documents such as maps, publications in PDF and for instance the final report can be downloaded by scientists and a large public.
A Catalogue of textual and archaeological references related to earthquakes of the prehistoric, Greek, Roman, Byzantine and Islamic periods has been completed. This tremendous work was prepared under the direction of Partner 6 (U. Tubingen). A shorter version of the catalogue (that allow an easy access to the large catalogue) is also completed with bibliography, chronology, abbreviations of languages, concordance of sigla and biographical data in Greek, Latin and Islamic authors.
In addition, maps of localities were damage attributed to large earthquakes have been prepared as a general site-map at 1:1 000 000 scale, with inset Damascus and vicinity, index, topographical names, geographical coordinates and grids. A list of large seismic events with corresponding maps is also available.
The field work included excavation in several sites: Dahes, Apamea, Al Harif and Crak des Chevaliers (Qalaat Hosn) in Syria, the Sicantarla Tell and Orontes Hittites bridge in Turkey, the column of Baalbek in Lebanon and Tell Assaydiyeh and archaeological sites in the Jordan Valley. Each site was the location of extensive field investigations with topographic mapping, detailed logging, collection of photographs and sample collection for isotopic dating. More than 300 samples have been dated (radiocarbon) and earthquake sequences were identified in excavations.
The activities of archaeology-archaeoseismology working group in APAME have led to the preparation of catalogues and maps and related database that form the most extensive collection of sources concerning the past earthquakes in the Middle East. It would therefore be quite important to continue updating and supplementing the database with the aim to complete and print the catalogues so that the work done remains accessible to all who are interested.
Precise 14C dating of the archaeological and paleoseismological sites was achieved by Partner 2 (U. Kiel) in collaboration with the different partners involved in the study of sites. In addition, methodological research was carried out to improve the reliability of 14C sample preparation for low carbon content samples, which are common in the region. A time frame related to the different civilizations that occupied the region was also established by including the information gathered by the partners in the catalogues and from the excavations. In Jordan, the two sites studied in collaboration with Partner 1 and Partner 7 at Karameh and Tell Saidiyyeh, were both faulting studies. A total of 38 samples (17 and 18 from Karameh and Tell Sadiyyeh respectively) were dated to give age boundaries to the observed faulting episodes. Both datasets proved very difficult to interpret.
In Lebanon, four seismic/faulting excavation sites were dated in Lebanon: TIS, Deir-al-Achayer, Jarmaq, and Rachaya, in collaboration with Partner1. The TIS site proved very difficult to date due to the very low carbon content of the samples from the site. Three dates were measured and indicate an event more than 150 years ago. No older limit could be established. Five 14C dates were measured from Deir-al-Achayer. The site of Jarmaq with 7 dates provided a correlation between a bracketted faulting event and the 1837 large earthquake. At the Rachaya site, 22 dates were obtained and shows the faulting episodes during the late Holocene time, among them the most recent event of 1759 is well defined.
In Syria, the 14C results of the archaeological excavations carried out in Der Dahess by Partner 6 and Partner 4 led to the conclusion that after a destruction of the monastery complex around 540 AD (526 AD earthquake in the seismicity catalogue) during the Byzantine period further signs of occupation might have no connections to earthquakes. A series of samples obtained from Crak des Chevaliers by partner 4, Directorate General of Antiquities, Syria, provided evidence of seismic activity extending from the late 10th Century up till the 15th Century, from the Early Islamic period to the Mamluk period. The Al Harif Roman aqueduct that was affected by past earthquakes, as it crosses the fault, was extensively studied and sampled (108 results) by Partners 1, 2 and 4. The construction is covered by travertine, a carbonate deposit that reached 80 cm on the north side of the wall. The 108 14C results lead to ambiguous conclusions so the cores were sampled for stable 18O and 13C in the hope to match these results with known climate records. The travertine has recorded 4 events after in construction between A.D. 1 and 120. Two could be of seismic or human origin, around A.D. 340 and A.D. 1150. The other two, around A.D. 660 and A.D. 1070 were probably caused by seismic events. Furthermore, 104 14C results were obtained from samples taken in trenches and the results are consistent with the occurrence of.
In Turkey, nine sites were studied in collaboration with Partner 1 and Partner 8. We obtained 4 results in Bosin, 9 results in Demirkopru, in Hanimaga, 18 results Harabe, 1 result in Imalu, 4 results in Lake, 19 results in Yazlik, 3 results in Yolu, and 11 results in Ziyaret. Most of the Turkish sites were locates in the Amik basin and proved carbon poor. However, the results clearly show a correlation with the 1408 earthquake along the DSF.
Finally, ten plates show a map of the fault as prepared by Partner 1 and to the right representation of the earthquake references as shown contained in the Catalogue of Historical Earthquakes according to time and latitude, which can visualise the recurrence of seismic events.
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