SEISMIC HAZARD IN GREECE BASED ON DIFFERENT STRONG GROUND MOTION PARAMETERS

The available Greek strong ground motion records to date are used in order to study the duration of strong-motion in Greece, covering magnitudes between 4.5 and 6.9 and distances from 1 km to 128 km. An attenuation relation of strong-motion duration is calculated and compared to earlier existing similar relations proposed for Greece and Japan. Furthermore, the seismic hazard for the area of Greece is assessed, using the strong-motion parameters of duration and peak ground acceleration. The results are presented in the form of a map according to which Greece is classified in four different categories of equal seismic hazard.     

NEW EMPIRICAL RESPONSE SPECTRAL ATTENUATION LAWS FOR MODERATE EUROPEAN EARTHQUAKES

This paper presents response spectral attenuation laws used in the new French Safety Rule, which is the reference for nuclear safety studies in France. Attenuation laws were derived from 965 horizontal and 485 vertical components from a two-step inversion method and accounts for geometrical spreading, anelastic attenuation and geological site condition. The datasets are mainly constituted of European strong motion records (83%) recently collected and homogeneously processed. In order to complete the distribution data beyond magnitude 6, a few American records were added, representing 17% of the datasets. The magnitude type and source-to-site distance definitions chosen to derive the laws are tested with respect to other definitions. These parametric tests induce a conservative law, for some magnitude and distance ranges of interest. The residual values between observed and predicted spectral accelerations are studied and do not exhibit any bias. The inferred laws are in good agreement with classical strong motion attenuation laws.     

EFFECTS OF SOIL LAYERING ON THE CHARACTERISTICS OF BASIN-EDGE INDUCED SURFACE WAVES AND DIFFERENTIAL GROUND MOTION

This paper studies the effects of soil layering in the basin based on the characteristics of basin-edge induced surface waves and associated differential ground motion. Seismic responses of various basin-edge models were simulated using software based on parsimonious finite difference staggered grid approximation of 2.5D eiastodynamic wave equation. Seismic responses of various models with different number of soil/soft rock layers but for a fixed thickness of deposit, fundamental frequency and impedance contrast revealed a decrease of surface wave amplitude with an increase in the number of layers in the basin. Shifting of dominant frequency towards the higher values was obtained with an increase of number of layers. An increase of dispersion of surface waves with an increase of number of soil layers in the basin was observed. A minor increase of Rayleigh wave velocity with an increase of number of soil layers was also obtained, but in the case of Love wave it was almost negligible.

Spectral analysis of the edge-induced surface waves revealed that the anomalous earthquake intensity may arise in a zone of width of 2.5–3.0 km, parallel to basin-edge and at an offset of 0.5–0.7 km from the edge. Maximum horizontal differential ground motion (HDGM) developed by Love wave (≈4.9×10^?2) was more than that of Rayleigh wave (≈9.4×10^?3). Large variation in HDGM caused by the surface waves was obtained with a change in the number of layers in the basin and maximum HDGM was observed when there were only two layers in the basin. It was inferred that the effect of soil layering in the basin was more on the Rayleigh wave as compared to the Love wave. Development of large HDGM near the basin-edge and its dependency on the number of soil layers reveals that basin-edge induced surface waves need special attention during seismic microzonation or seismic hazard prediction.     

STRONG GROUND MOTIONS AND DAMAGE PATTERNS FROM THE 1999 DUZCE EARTHQUAKE IN TURKEY

The M _w , 7.1 Duzce earthquake occurred on 12 November 1999 along the North Anatolian Fault in northwestern Turkey. This paper documents observations from a field reconnaissance team, addressing two principal aspects of this significant earthquake: the recorded ground motions and the distribution and severity of the earthquake effects on the built environment. In general, the recorded ground motions from this earthquake were smaller than predicted by ground motion predictive equations available at the time of the event. One anomalous recording is presented and potential causes for this irregular motion based on observations from field reconnaissance are discussed. The effects of rupture directivity on the near-fault recordings are assessed and the effects of soil conditions on the recorded ground motions are examined. The patterns of building damage based on post-earthquake reconnaissance are presented for the most strongly shaken cities in the near-fault region: Duzce, Kaynasli, and Bolu. Damage in Duzce was concentrated in the southern part of the city, which is underlain by softer sediments. Damage in Bolu was distributed evenly throughout the city; whereas damage was concentrated on more recent alluvial sediments in Kaynasli. No evidence of liquefaction or ground failure was observed in the populated areas surveyed after the earthquake.     

ESTIMATION OF GROUND MOTION ACCELERATION AND BUILDING RESPONSE TO A LONG DISTANCE EARTHQUAKE

In October 1995 an earthquake with a magnitude of 7 on the Richter scale occurred in Sumatra, 450 km from Singapore. Tremors were felt by occupants of several buildings in Singapore and were recorded as an RMS acceleration value by instruments installed in a high-rise condominium. Based on this value and considering instrumental effects, site conditions and building characteristics, this paper investigates the ground motion accelerations and the building response.     

Correspondence

EUROPE

The Scotland of Our Fathers. By Elizabeth S. Haldane. London : A. Maclehose and Co., 1933. Price 18s. 6d. net.

Fifty Tears and More of Sport in Scotland. By the Duke of Portland. London : Faber and Faber, 1933. Price 21s.

The Woodlands and Marshlands of England. By H. A. Wilcox. University Press of Liverpool; London: Hodder and Stoughton Ltd., 1933. Price 6s.

The Face of Scotland. By Harry Batsford and Charles Fry. London : B. T. Batsford Ltd., 1933. Price 7s. 6d. net.

The Charm of Brittany. By R. A. J. Walling. London : George G. Harrap and Co. Ltd., 1933. Price 7s. 6d.

Poland. By Roman Dyboski. London : Ernest Benn Ltd, 1933. Price 21s.

Rumania : Its History, Politics and Economics. By George Glenton Logio Manchester : Sherratt and Hughes, 1932. Price 5s.

Belgium : The Land and its People. By Clive Holland. London : Herbert Jenkins Ltd., 1933. Price 5s.

Pavements and Peaks. By Anthony Bertram. London : Chapman and Hall Ltd., 1933. Price 7s. 6d.

AFRICA

My Farm in Lion Country. By Joyce Boyd. London : Hurst and Blackett Ltd., 1933. Price 12s. 6d.

AMERICA

The Explorers of North America, 1492–1806. By J. B. Brebner. London : A. and C. Black Ltd., 1933. Price 18s.

Land of Feast and Famine. By Helge Ingstad. London : Victor Gollancz Ltd., 1933. Price 16s.

From Pacific to Atlantic: South American Studies. By Kenneth G. Grubb. London : Methuen and Co. Ltd., 1933. Price 10s. 6d.

True North. By Elliott Merrick. New York: Charles Scribner's Sons, 1933. Price 10s. 6d.

AUSTRALASIA

Gold Dust and Ashes. By Ion L. Idriess. Sydney : Angus and Robertson, 1933. Price 6s.

GENERAL

Light on the Dark Continent. By Garveth Wells. London : Jarrolds Ltd., 1933. Price 16s.

The Horse and the Sword. By Harold Peake and H. J. Fleure. London : Humphrey Milford, Oxford University Press, 1933. Price 5s.

The Problem of Disarmament. Edited by R. Schmidt and A. Grabowsky. Berlin : Carl Heymanns Verlag, 1933. N.p.

Nansen of Norway. By C. Turley. London : Methuen and Co. Ltd., 1933. Price 5s.

Voyage of the “ Parma.” By A. J. Villiers. London : Geoffrey Bles, 1933. Price 25s.

Come Easy, Go Easy. By Arthur Mason. London : Jonathan Cape, 1933. Price 7s. 6d.

Far Vistas. By Sir Percival Phillips. London : Methuen and Co. Ltd., 1933. Price 12s. 6d.

Round the World to Freedom. By Major Paul Stoffa. London : John Lane (The Bodley Head) Ltd., 1933. Price 7s. 6d.

Seaplane Solo. By Francis C. Ghighester. London : Faber and Faber, 1933. Price 10s. 6d.

Thames to Tahiti. By Sidney Howard. London : George Bell and Sons Ltd., 1933. Price 10s. 6d.

Scamper Tour to Rhodesia and South Africa. By Mrs. Maude Speed. London : Longmans, Green and Co. Ltd., 1933. Price 7s. 6d.

Trade Winds. By Louis Kornitzer. London : Geoffrey Bles, 1933. Price 10s. 6d.

Historical Geology. By Raymond C. Moore. New York : McGraw‐Hill Book Co. Inc., 1933. Price 24s.

A Political Geography of the British Empire. By C. B. Fawcett, B.Litt., D.Sc. London: University of London Press, 1933. Price 18s.

EDUCATIONAL

Economic and Social Geography. By Ellsworth Huntington, Frank E. Williams and Samuel van Valkenburg. New York and London : John Wiley and Sons, 1933. Price 23s.

The Story Atlas. Edited by John Stirling. London : Ivor Nicholson and Watson, n.d. Price 31s. 6d.

Our World To‐day. By W. R. Kermack. Edinburgh : W. and A. K. Johnston Ltd., 1933. Price 2s. 6d.

This Land of Ours. By Wm. Platt. London : George Allen and Unwin Ltd, 1933. Price 2s.     

Contemporary Sorted Patterned Ground in Low Altitude Areas of Tasmania

This paper summarises the distribution of patterned ground phenomena in Tasmania. It presents observations of low altitude sorted stone circles forming on glacial and alluvial deposits in the vicinity of Queenstown, Western Tasmania. Evidence suggests that freeze‐thaw derived patterned ground could develop in most inland valleys in Tasmania where cold air drainage causes sub‐zero ground temperatures in winter and permits the formation of ground and segregation ice to low elevations. Field observations suggest that patterned ground can only develop where freeze‐thaw processes are not inhibited by vegetation. The occurrence of patterned ground below altitudes of 900 m asl in Tasmania is largely a result of anthropogenic disturbance.     

The relationship between school ground design and intensity of physical activity

In this study, we investigated the relationship between school ground design and children's physical activity levels. In particular, we were interested in understanding the contribution of ‘green’ school ground design to physical activity levels. Data for this study were collected at an elementary school in Australia and in Canada. At each school, scans of Target Areas were completed to record the students' location and intensity of physical activity, based on the System for Observing Play and Leisure Activity in Youth (SOPLAY) (Australia: 23 scans, 6 Target Areas; Canada: 18 scans, 7 Target Areas). At both schools, the highest percentage of children present was engaged in vigorous physical activity on the manufactured equipment (42% of children/scan). Similarly, at both schools, the green area encouraged the highest percentage of children present to be engaged in moderate physical activity (47% of Australian children/scan, 51% of Canadian children/scan). The patterns of sedentary behavior differed slightly between countries. At the Australian school, the paved sporting courts (57%) and the paved canteen courtyard (50.5%) promoted the highest degree of sedentary play. At the Canadian school, the treed grassy berm (42%) and the treed concrete steps (43%) encouraged the highest percentage of sedentary behavior, followed by the open asphalt (34%). These results are also discussed in light of gender distribution. We conclude with a discussion of the design and cultural factors that influence children's physical activity on school grounds. We argue that if school grounds are to realize their potential to promote physical activity, they should include a greater diversity of design features and ‘green’ elements that engage children of varying interests and abilities in active play.     

The Value of Rents: Global Commodity Chains and Small Cocoa Producers in Ecuador

Drawing on the Marxian theory of ground rent, this paper develops an analysis of “global commodity chains” (GCCs) with agrarian roots. There is an acknowledgement that the concentrated downstream governance of primary commodity‐based GCCs has created a set of “asymmetrical” power relations which blocks the transmission of value upstream towards small producers. This paper argues that this research under‐specifies what is meant by value and rent, and in doing so marginalises the analysis of value production before its journey through inter‐firm relations. We demonstrate the importance of theorising the value constitution of commodities produced on the land and the forces that contest the payment of ground rent and thereby shape the geography of GCCs. Based on empirical research conducted around Ecuador's “post‐neoliberal” cocoa re‐activation plan, we identify the class politics and production mechanisms through which value and rent escapes the hands of a stratified network of small owner producers.     

GROUND MOTION DOMINANT FREQUENCY EFFECT ON THE DESIGN OF MULTIPLE TUNED MASS DAMPERS

Utilising the Kanai-Tajimi and Clough-Penzien spectrums and the pseudo-excitation algorithm in the frequency domain, parametric study is performed to examine the effect of the dominant frequency of ground motion on the optimum parameters and effective-ness of multiple tuned mass dampers (MTMD) with identical stiffness and damping coefficient but with unequal mass. The examination of the optimum parameters is con-ducted through the minimisation of the minimum values of the maximum displacement and acceleration dynamic magnification factors of the structure with the MTMD. The optimum parameters of the MTMD include the optimum frequency spacing reflecting the robustness, the average damping ratio and the tuning frequency ratio. Minimisation of the minimum values of the maximum displacement and acceleration dynamic mag-nification factors, nondimensionalised respectively by the maximum displacement and acceleration dynamic magnification factors of the structure without the MTMD, is used to measure the effectiveness of the MTMD. The results indicate that in the two cases where both the total mass ratio is below 0.02 and the total mass ratio is above 0.02, but the dominant frequency ratio of ground motion is below unity (including unity), the earthquake ground motion can be modelled by a white noise. It is worth noting, however, that for the total mass ratio above 0.02, the Kanai-Tajimi Spectrum or Clough-Penzien spectrum needs to be employed to design the MTMD for seismic structures in situations where the dominant frequency ratio of ground motion is beyond unity.