Ancient Earthquakes Research Articles

Fossil shorelines at Corfu and surrounding islands deduced from erosional notches

New geomorphological investigations along the coasts of Corfu, Othonoi, Paxoi, and Antipaxoi Islands allowed the identification of recent fossil shorelines. Former sea-level positions were deduced from sea-level indicators. A ‘modern’ tidal notch, submerged c. −20 cm, was observed in all studied islands. This notch is regarded to have been submerged by the global sea-level rise that occurred during the 19th and 20th centuries at a rate exceeding the possibilities of intertidal bioerosion. Its presence provides evidence that no vertical tectonic movements occurred since its formation. On Corfu, impacts of ancient earthquakes have left some marks of emergence at about ≥+130 ± 11, +110 ± 11, +65 ± 11, +40 ± 11, and +25 ± 11 cm, as well as marks of submergence at about −40 to −50, −85 ± 11, −120 ± 11, and −180 ± 11 cm. The emergence of +130 ± 11 cm, previously dated at about 790–400 cal. bc, was detected through erosion notches at various sites in the western part of Corfu and appears to continue even more west, at Othonoi Island. Tidal notches submerged at depths exceeding 0.4 m were observed in the northeastern part of the island and suggest the local occurrence of a sequence of four coseismic subsidences, with average vertical displacements of 40 cm, during at least the last few millennia. At Paxoi and Antipaxoi, Holocene vertical movements seem to have been mainly of subsidence. At Paxoi, the ‘modern’ notch was found at about −20 to −30 cm, while four more submerged tidal notches were distinguished at about −40 ± 11, −60 ± 11, −75 ± 11, and −90 ± 11 cm, while in Antipaxoi, three submerged tidal notches were distinguished at about −60 ± 11, −75 ± 11, and −120 ± 11 cm.

Comment on Analyses of Seismic Deformation at the Kibyra Roman Stadium, Southwest Turkey by Volkan Karabacak, Önder Yönlü, Eray Dökü, Nafiye Günenç Kıyak, Erhan Altunel, Şükrü Özüdoğru, Cahit Çağlar Yalçıner, and Hüsnü Serdar Akyüz

The ancient city of Kibyra, which has been damaged by ancient earthquakes, is located on the middle part of Burdur‐Fethiye Fault Zone (SW Turkey). The existence of an active NNE‐SSW‐trending left‐lateral fault cutting the stadium of Kibyra has been previously discussed in many publications (Akyüz and Altunel, , ; Karabacak, ). Karabacak et al. () also adhere to this view and restate it in the recent article published in Geoarchaeology. However, there is no evidence directly indicating a fault cutting the stadium and the earthquake damage to the stadium was most likely caused by ground shaking. In conclusion, the arguments, observations and interpretations presented by Karabacak et al. () are misleading in key respects and must be reviewed.

On a more precise assessment of seismic hazards for the city of Ulaanbaatar, Mongolia

The recent geological, geophysical, and paleoseismic research of the Hustai, Emeelt, and Gunjiin active seismogenic faults in the vicinity of Ulaanbaatar provided evidence of prehistoric seismic events there. In particular, dislocations of two fault-forming paleo-earthquakes were revealed in the Gunjiin tectonic zone. The shocks occurred in the Late Pleistocene-Early Holocene. The presence of ruptures, initially identified by morphological characteristics, was proven by trenching studies and materials of geophysical profiles. The magnitudes of the ancient earthquakes are estimated to be 6.5–7.0. The obtained results provide grounds for reassessment of the possible level of seismic hazards for the territory of Ulaanbaatar to at least 8.

Biomarkers heat up during earthquakes: New evidence of seismic slip in the rock record

Research Article| February 01, 2014 Biomarkers heat up during earthquakes: New evidence of seismic slip in the rock record Heather M. Savage; Heather M. Savage 1Lamont-Doherty Earth Observatory, Columbia University, Palisades, New York 10964, USA Search for other works by this author on: GSW Google Scholar Pratigya J. Polissar; Pratigya J. Polissar 1Lamont-Doherty Earth Observatory, Columbia University, Palisades, New York 10964, USA Search for other works by this author on: GSW Google Scholar Rachel Sheppard; Rachel Sheppard 1Lamont-Doherty Earth Observatory, Columbia University, Palisades, New York 10964, USA Search for other works by this author on: GSW Google Scholar Christie D. Rowe; Christie D. Rowe 2Department of Earth and Planetary Sciences, McGill University, 3450 University Street, Montréal, H3A 0E8 Quebec, Canada Search for other works by this author on: GSW Google Scholar Emily E. Brodsky Emily E. Brodsky 3Department of Earth and Planetary Sciences, University of California–Santa Cruz,1156 High Street, Santa Cruz, California 95064, USA Search for other works by this author on: GSW Google Scholar Author and Article Information Heather M. Savage 1Lamont-Doherty Earth Observatory, Columbia University, Palisades, New York 10964, USA Pratigya J. Polissar 1Lamont-Doherty Earth Observatory, Columbia University, Palisades, New York 10964, USA Rachel Sheppard 1Lamont-Doherty Earth Observatory, Columbia University, Palisades, New York 10964, USA Christie D. Rowe 2Department of Earth and Planetary Sciences, McGill University, 3450 University Street, Montréal, H3A 0E8 Quebec, Canada Emily E. Brodsky 3Department of Earth and Planetary Sciences, University of California–Santa Cruz,1156 High Street, Santa Cruz, California 95064, USA Publisher: Geological Society of America Received: 02 Jul 2013 Revision Received: 24 Sep 2013 Accepted: 02 Oct 2013 First Online: 09 Mar 2017 Online ISSN: 1943-2682 Print ISSN: 0091-7613 © 2014 Geological Society of America Geology (2014) 42 (2): 99–102. https://doi.org/10.1130/G34901.1 Article history Received: 02 Jul 2013 Revision Received: 24 Sep 2013 Accepted: 02 Oct 2013 First Online: 09 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation Heather M. Savage, Pratigya J. Polissar, Rachel Sheppard, Christie D. Rowe, Emily E. Brodsky; Biomarkers heat up during earthquakes: New evidence of seismic slip in the rock record. Geology 2014;; 42 (2): 99–102. doi: https://doi.org/10.1130/G34901.1 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGeology Search Advanced Search Abstract During earthquakes, faults heat up due to frictional work. However, evidence of heating from paleoearthquakes along exhumed faults remains scarce. Here we describe a method using thermal maturation of organic molecules in sedimentary rock to determine whether a fault has experienced differential heating compared to surrounding rocks. We demonstrate the utility of this method on an ancient, pseudotachylyte-hosting megathrust at Pasagshak Point, Alaska. Measurements of the ratio of thermally stable to thermally unstable compounds (diamondoids/n-alkanes) show that the melt-bearing rocks have higher thermal maturity than surrounding rocks. Furthermore, the mineralogy of the survivor grains and the presence of any organic molecules allow us to constrain the temperature rise during the ancient earthquakes to 840–1170 °C above ambient temperatures of ∼260 °C. From this temperature rise, we estimate that the frictional work of the earthquake was ∼105–228 MJ/m2. Using experimental friction measurements as a constraint, we estimate that the minimum slip necessary for heating was ∼1–8 m. This paper demonstrates that biomarkers will be a useful tool to identify seismic slip along faults without frictional melt. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.

They Call You the Parisian: On Thera by Zeruya Shalev

Zeruya Shalev writes on marital crises through the prism of Jewish legends and Greek myths on catastrophic themes. The destruction of the Second Temple, the rift between the biblical Kingdom of Israel and the Kingdom of Judea, and an ancient earthquake that decimates an entire civilization serve as analogies to events in the personal lives of her characters. The article examines Shalev’s novel Thera , whose protagonists are archeologists married to one another, and Wilhelm Jensen’s Gardiva: A Pompeiian Fancy (1903)—whose protagonist is also an archeologist, who received a fascinating treatment in Sigmund Freud’s Delusion and Dream in Wilhelm Jensen’s Gardiva (1907). Both Shalev’s Thera and Jensen’s Gardiva use an ancient artwork related to a cataclysmic natural disaster to stimulate the male protagonist’s falling in love with a woman. The scientific archeological investigation serves as an excuse, camouflage, and metaphor for real life taking place in the present.

Comparison of seismotectonic peculiarities of Altai Mountains and Mongolian Altai

The paleoseismogeological studies within the two representative segments of fold systems in the Altai mobile belt (Altai Mountains and Mongolian Altai) have been carried out. These studies revealed the primary seismodislocations (seismic ruptures) of both the ancient historic and prehistoric strongest earthquakes. Based on amplitudes of single displacements (reverse fault and normal fault motions were 0.5–1.6 m) and with the significant strike slip component (more than 1.5 m) taken into account, the magnitude of ancient events in the Altai Mountains was determined at approximately 7.5. The recurrence period is 1400 years on average for the M = 7.0 events and 2100 years for the M = 7.5 ones. In the western Mongolian Altai, reverse fault motions were up to 2 m, corresponding to an earthquake magnitude of about 8.0 (an analog with the 1931 Fuyun earthquake). The recurrence period for the strongest earthquakes in Mongolian Altai was longer than that for the Altai Mountains, about 3000 years. This can be explained by higher magnitude values for western Mongolian Altai. It also can be concluded that the seismic regimes of the Altai Mountains and Mongolian Altai remained almost unchanged during the entire Holocene.

Under the Action of Earthquake Ancient Timber Building Column Small Feet Slip Phenomenon Analysis

In ancient China timber building earthquake damage records, often about "column small feet slip", scholars in ancient timber buildings for the seismic performance study, also thought that "column small feet slip" is one of the reasons for the ancient building in the earthquake Could be survived. This article through to column small feet slip phenomenon, to lead to column small feet slip condition were analyzed, and "column small feet slip" seismic effect evaluation, is to the ancient timber aseismic performance research achievements added.

Thermal decomposition along natural carbonate faults during earthquakes

Earthquake slip is facilitated by a number of thermally activated physicochemical processes that are triggered by temperature rise during fast fault motion, i.e., frictional heating. Most of our knowledge on these processes is derived from theoretical and experimental studies. However, additional information can be provided by direct observation of ancient faults exposed at the Earth’s surface. Although fault rock indicators of earthquake processes along ancient faults have been inferred, the only unambiguous and rare evidence of seismic sliding from natural faults is solidified friction melts or pseudotachylytes. Here we document a gamut of natural fault rocks produced by thermally activated processes during earthquake slip. These processes occurred at 2–3 km depth, along a thin (0.3–1.0 mm) principal slip zone of a regional thrust fault that accommodated several kilometers of displacement. In the slip zone, composed of ultrafine-grained fault rocks made of calcite and minor clays, we observe the presence of relict calcite and clay, numerous vesicles, poorly crystalline/amorphous phases, and newly formed calcite skeletal crystals. These observations indicate that during earthquake rupture, frictional heating induced calcite decarbonation and phyllosilicate dehydration. These microstructures may be diagnostic for recognizing ancient earthquakes along exhumed faults.

Evidence of ancient earthquakes in the alluvial deposits of Katun River (Uimon depression, Gorny Altai)

NEOTECTONIC STRUCTURE AND SEISMICITY OF THE STUDY AREAInstrumental observations show that the GornyAltai is a seismoactive territory. For solving problemsconcerning the evolution of its seismicity, analysis ofdifferent type deformations, which disturb the primarystructures of sedimentary complexes and can be foundin natural outcrops and artificial sections, have gainedincreasing importance recently. Examples of suchstudies are for the Neopleistocene interval are publications [1, 2] and [7] for the upper Holocene. Paleoseismogeological studies have been mostly concentratedin the southeastern part of the Gorny Altai, where thetwo largest basins (Chuya and Kurai) are located andwithin the limits of major river valleys (Chuya andKatun). However, specialized paleoseismogeologicalstudies in the central part of the Gorny Altai, wherethe Uimon basin, which is third in size, is located(Fig. 1), may also be promising.To the north, the Uimon basin is framed by theTerekta and Kamza ridges (see Fig. 1) of 2000 to 2900m high. Their block structure and general decrease inaltitude towards the depression is determined by acombination of three fault systems of different orientations: northwestern, northeastern, and sublatitudinal [3]. The geological and geophysical data indicatethe thrust of the northern mountain framing onto theCenozoic deposits of the Uimon depression along theSouth Terekta fault zone; the deposits are involved inthe tectonic motion and a series of tectonic scarps isformed [3, 10]. To the south, the intermontane is confined by the branches of Katun Ridge of 2000 to3000 m high and higher. Their neotectonic structure isdetermined by a combination of submeridional andarcshaped faults [3].In the mountain framing of the basin and in theadjacent areas (including Rudny Altai), earthquakesof up to the 12th energy class are recorded by a regularseismic network (see Fig. 1). An example of a relativelystrong events is the Tyngur earthquake of September18, 1997, whose magnitude was 4.0 to 5.2 based on thedata of various agencies. The regional value of magnitude was

Coal maturation by frictional heat during rapid fault slip

The detection of frictional heating effects along faults provides key insight into the dynamics of earthquakes and faulting. Thermal maturity of organic matter has been considered a possible fault‐thermometer that records the frictional heat signature of ancient earthquakes. However, whether or not organic matter can mature on the order of seconds, typical earthquake rise time, remains uncertain. Here we present the results of experiments aimed at revealing coal maturation by frictional heat generated at slip velocities representative of natural earthquakes of up to 1.3 m/s. Our results show that coal can mature coseismically in ∼11 seconds at temperatures induced by frictional heat ranging from 26 to 266°C. Even with a temperature rise to only 28.7°C over 15 m displacement in ∼3.2 hours, coal can slightly mature within a shear localized zone. The commonly used kinetic model of vitrinite maturation cannot predict the experimental results. A kinetic model involving the effect of flash temperature at grain contacts and mechanochemical effects on reaction kinetics is necessary to better estimate heat generation along a fault.

All That Rubble Leads to Trouble: Reassessing the Seismological Value of Archaeological Destruction Layers in Minoan Crete and Beyond

Since its discovery in the beginning of the twentieth century by British archaeologist Arthur Evans, the Bronze Age (Minoan) civilization of Crete (Greece, ca. 3000–1200 B.C.) received considerable scholarly, scientific, and popular attention (e.g., Papadopoulos, 2005). Although subject to critique and revision (e.g., Hamilakis, 2002), Evans’s ideas and hypotheses about Minoan society remain remarkably central to modern archaeological research on the island (e.g., Schoep, 2010). The recognition of the disruptive effects of earthquakes on Minoan society represents one of Evans’s enduring legacies. Earthquakes have been considered as responsible for the successive destructions of the palace of Knossos (Evans, 1928) and as convenient time markers for Minoan archaeological periods (e.g., Driessen, 1987). Nowadays, they are often seen by Minoan archaeologists as an unattractive explanatory concept (Cadogan, 2011), at least when divorced from their wider social, political, and economic contexts (e.g., Driessen and Macdonald, 1997). Fear of catastrophism, undesirable use of deus ex machina phenomena, and resistance to Occam’s razor ( lex parsimoniae )asa heuristic guide to archaeological explanation partly account for this situation. The ambiguous value of Minoan archaeological remains as indicators of ancient earthquakes may also have played a role: although damage typologies have been put forward in Greek archaeological contexts (Stiros, 1996), their applicability to Minoan earthen and rubble constructions is often limited. As a result, recognition of ancient earthquake damage on Minoan archaeological sites is frequently based on isolated observations (e.g., Sakellarakis and Sapouna-Sakellaraki, 1981; Vallianou, 1996; Monaco and Tortorici, 2004) and limited archaeological/palaeoenvironmental evidence (e.g., Gorokhovich, 2005), thereby perpetuating a catastrophist research tradition initiated by Evans more than a century ago. In the current context of increased scientific and scholarly interest in evaluating the role of archaeological data in seismotectonic studies, we feel that the time is ripe to critically evaluate the nature of Minoan archaeological data …

A comprehensive classification of Earthquake Archaeological Effects (EAE) in archaeoseismology: Application to ancient remains of Roman and Mesoamerican cultures

One of the key tasks in archaeoseismolo`gy is to test whether the recorded building damage in ancient cities can be related to ancient earthquakes. Archaeologists often claim abandonment, ruin or war instead of natural causes to explain the recorded damage in archaeological findings. This work proposes a comprehensive classification of Earthquake Archaeological Effects (EAE) based on the seismic deformation of buildings and monuments within urban areas of ancient cities. Accordingly, the proposed EAE classification differentiates the seismic deformation on the structure of buildings in two groups: from transient shaking and from permanent ground deformation. The first type of EAE corresponds to fractured walls and fallen key stones in arches, for example. The second type of EAE are tilted walls and shock breakouts of flagstones due to basement failure. To illustrate the proposed EAE classification, examples of earthquake damage on ancient buildings are described: Baelo Claudia and Tolmo de Minateda cities (Roman and Visigothic Periods, 1st–6th century AD, respectively, South of Spain) and Teotihuacán and Tarascan sites (Early Classic ca. IVth century AD, and Upper Post-Classic Period XIII th century AD, Central Mexico).

Archaeoseismology: Past, present and future

Reflecting on the burgeoning scientific discipline of archaeoseismology, a clear trend can be discerned. What started as an “extravaganza” in a good story (archaeological perspective) became a multidisciplinary effort to get a maximum amount of information on the parameters of ancient earthquakes out of archaeological evidence (seismological and archaeoseismological perspective). A clear shift can be observed from a more qualitative approach focussing on the extension of earthquake catalogues to a more quantitative approach concerning site effects. Looking into the future, the vocation of archaeoseismology may lie elsewhere. Archaeoseismology could become a holistic interdisciplinary discipline concerned with establishing the essential earthquake culture in a region (sociological perspective).

Basic Parameters and Characteristics of Seismicity in Mongolia

Much of the territory of Mongolia is located in highly seismic areas of Central- Asian seismic belt and is subjected to frequent and large earthquakes. Its western half is particularly seismically dangerous. Only in twentieth century more than 60 earthquakes with M>5.5 (7 to 11-12 - intensity) occurred here, among which tens of earthquakes were responsible for severe destruction of the earth surface, and seismic disasters of 1905, 1931 and 1957 were accompanied by seismotectonic deformations to several hundred kilometers in length. Judging from the retained traces of ancient earthquakes and the chronicles, similar and probably larger seismic events occurred here in the recent past.DOI: http://dx.doi.org/10.5564/pmas.v0i4.39Proceedings of the Mongolian Academy of Sciences 2007 No 4 pp.36-49

A Pleistocene landslide-dammed lake, Jinsha River, Yunnan, China

On both sides of the Jinsha River valley near Benzilan, Dêqên, northwest of Yunnan, China, a series of varied lacustrine deposits have been discovered under the fourth terrace (Q 3 2). Landslide debris has been identified underlying the lacustrine deposits, indicating that the lacustrine deposits were caused by a landslide damming the Jinsha River. U-series dating shows that the age of the upper and middle portions of the lacustrine deposits on the right bank were 55.4 ± 3.5 and 82.1 ± 6.6 ka respectively. Lacustrine deposits on the left bank have been dated to 122.0 ± 12.4 ka at the bottom, which indicates that the large-scale landslide was formed before 122.0 ± 12.4 ka and the paleo-lake was developed within the early stage to the mid-stage of the Late Pleistocene. The characteristic of spore-pollen and high content of CaCO 3 in the lacustrine clays reveal that the paleoclimate was semi-arid with less heavy rainfall. Considering the regional neotectonic background, the authors prefer to interpret that the Benzilan ancient landslide-dammed lake was caused by an ancient earthquake. The discovery of the ancient landslide-dammed lake provides significance to the understanding of the formation and evolvement of calamitous geological hazards along large rivers.

Paleoseismogeological Investigations in a “Seismic Gap” in the Northwest Caucasus Compared to the West Himalayan Region

In this article we have compared the results of seismotectonic and paleoseismogeologic investigations for representative segments of the two fold systems of the Alpine-Himalayan mobile belt (in the North- west Caucasus and West Himalayas). It has been found that during the previously identified “seismic gaps,” in both cases, we are dealing with primary dislocations (seismic ruptures) of ancient historical and prehistoric strong earthquakes. According to estimations, the magnitude of one-act seismogenic displacements in the first region was about 6.5-7.0 m, and the recurrence period ranges from 500 to 1500 years on average. In the West Himalayas, the overthrust displacements along the ruptures were 6-7 m, which corresponds to an 8.0-magnitude earthquake. At the same time, the recurrence period of strong earthquakes during a seismic gap in the Himalayas was 500-1000 years, which is similar to that in the Caucasus. The data collected also demonstrate the correct preliminary estimation of the seismic potential of zones of seismic quiescence in both the studied fold systems.

Timing of the Landslide-Dammed Lake Triggered by Earthquake, at Toyama River, Central Japan

Huge landslides triggered by strong earthquakes or torrential rains can result in unstable natural dams that pose serious risks to humans. In this study, we attempt to document the age of an ancient earthquake that produced a landslide-dammed lake. A buried forest found in the Toyama River area of the southern Nagano Prefecture, central Japan, provides evidence of this event. The dammed lake formation has been previously estimated to have occurred in AD 714. However, the age of the dam and the way it was formed have never been directly determined. To determine the position and timing of the landslide dam, we analyzed the radiocarbon content of branches and wood fragments from a brecciated deposit. We show that the 14C dating method is suitable for clarifying the timing of burial for a variety of trees, although the method does not produce a narrow age for the event. In addition to the dating, we determined the landslide dam's position and reconstructed the formation of the lake.

The 2nd century AD earthquake in central Italy: archaeoseismological data and seismotectonic implications

The 2nd century AD earthquake in central Italy is only known by an epigraph that mentions restorations to a damaged weighing-house at the ancient locality of Pagus Interpromium. The available seismic catalogues report this event with the conventional date of 101 AD, a magnitude M aw of 6.3, and an epicentral location at the village of San Valentino in Abruzzo Citeriore, in the province of Pescara. In order to improve the knowledge of the damage pattern, we gathered all the archaeological data collected during modern excavations at sites located in the area, which were presumably struck by the earthquake. This information is mainly represented by (1) stratigraphic units due to the sudden collapse of buildings over still frequented floors; (2) stratigraphic units demonstrating restoration or re-building of edifices; (3) stratigraphic units formed as the result of the abandonment of sites or of their lack of frequentation for decades or centuries. Only stratigraphic evidence consistent with an earthquake occurrence during the 2nd century AD has been considered. The most recent archaeological material found in a collapsed unit is a coin of Antoninus Pius, dated at 147–148 AD. This may represent a post quem date very close to the occurrence of the earthquake. The gathered information, plus the stratigraphic data that excluded the earthquake occurrence at some sites, has allowed us to roughly delineate an area of possible damage, including the Sulmona Plain and surrounding areas. Comparisons between the possible 2nd century damage distribution and (i) the damage patterns of more recent historical events that have struck the investigated area, (ii) the distribution of virtual intensities obtained by simulating an earthquake having an epicenter in the Sulmona Plain and applying an intensity attenuation relationship and (iii) a shaking scenario obtained by modelling the activation of the major active fault of the Sulmona Plain area (the Mt. Morrone fault) have revealed consistency between the ancient earthquake and the activation of this fault. Since no other historical events can be attributed to this active fault, we conclude that the time that has elapsed since the last fault activation should be in the order of 1,850 years, i.e. a time span that is very close to the recurrence interval of Apennine seismogenic sources. Moreover, considering the fault length, the causative source may be responsible for earthquakes with M up to 6.6–6.7. The comparison between the presumed 2nd century damage and the shaking scenario suggests that the magnitude mentioned is consistent with the presumed effects of the ancient earthquake. Finally, considering that Sulmona (the most important town in the region investigated) is located in the middle of the Mt. Morrone fault hanging wall, we consider it as the probable epicentral area. Therefore, to summarise the information on the 2nd century AD earthquake, we can conclude that (i) it occurred shortly after 147–148 AD; (ii) a magnitude M w 6.6–6.7 can be attributed to it and (iii) the probable macroseismic epicentral area was Sulmona.

Earthquake Archaeology--Just a Good Story?

Investigating the remains of past human activity in search of evidence of ancient earthquakes is the principal objective of archaeoseismology. In this regard, it sits within a continuum of overlapping and complementary subdisciplines that span the broad research realm of earthquake science, specifically bridging the gap between instrumental and historical seismology on one side and paleoseismology and earthquake geology on the other. Each of these research fields focuses on a particular source of data, applies appropriate analytical methods and techniques, and targets a specific time window, which in the case of archaeoseismology tends to be cultural material data spanning the last few millennia. Ultimately, however, each of these discrete subdisciplines converges on a common goal: to reduce the seismic hazard within a region through a better understanding of its earthquake history. “Ancient accounts of earthquakes do not help us much; they are incomplete, and accuracy is usually sacrificed to make the most of a good story.” — Charles Richter Half a century ago, Charles Richter (1958) complained that “ancient accounts of earthquakes do not help us much; they are incomplete, and accuracy is usually sacrificed to make the most of a good story.” Those remarks were directed at documentary records of antique earthquakes, but in the intervening 50 years a concerted effort to rigorously extract meaningful quantitative seismic parameters from textual archives has ensured that historical seismology is now an important facet of modern seismic-hazard assessment. Archaeological data, …

Dislocations caused by ancient strong earthquakes in the Elbrus region

The probability of natural disastrous phenomena in the Northern Caucasus is a topical scientific problem. According to materials of the Map of General Seismic Zonation of the Russian Federation, the Elbrus region belongs to the seismic impact zone with a magnitude of as much as 8 or 9 [1]. Estimation of seismic risk for the Caucasian region based on the cluster analysis of geological–geophysical and seismological data [2] showed that the Elbrus region includes a potential seismic focus (PSF) with a predictable maximal magnitude of expected earthquakes equal to 7.2 [3]. At the same time, the region also incorporates a vast calm zone in terms of seismicity, for which any instrumental and macroseismic data on earthquakes are absent. This situation is accounted for by the fact that the melt in a vast magma chamber existing at present beneath Mt. Elbrus in the central part of the Earth’s crust [4–6] promotes the stress relief. Therefore, strong seismic quakes do Dislocations Caused by Ancient Strong Earthquakes in the Elbrus Region E. A. Rogozhin, A. N. Ovsyuchenko, and A. V. Marakhanov Presented by Academician S.A. Fedotov August 17, 2007