stable carbon and oxygen isotopic evidence for late pleistocene to middle holocene climatic fluctuations in the interior of southern africa stable carbon and oxygen isotope analyses of ungulate grazers from four archaeolog ical sites located in different environs within the caledon river valley have provided a relatively well dated proxy palaeoenvironmental and palaeoclimatic sequence for the period between 16 000 and 6000 calendar cal yr bp within the overall trend towards hot mid holocene temperatures and a summer rainfall pattern stable carbon isotope results show that there were three periods when growth season temperatures were cool enough for c3 grasses to be present 16 000 14 000 10 200 9600 and 8400 8000 cal yr bp similar trends were recorded in stable oxygen isotope values reflecting shifts in either temperature or available moisture although having a similar pattern to that of the lower altitude site sites situated in foothills and montane portions of the valley consistently maintained lower temperatures until the mid holocene altithermal at this time growth season temperatures warmed sufficiently for a 100 c4 grassland to expand in altitude from the warmer low lying localities in relation to present understanding of synoptic and global climatic patterning these findings suggest that the early to middle holocene transition was not a gradual warming trend but rather it was marked by a series of climatic fluctuations of particular note is the possible global rather than regional occurrence of the 8200 cal yr bp event copyright 2002 john wiley sons ltd journal of quaternary science

short term and intermediate term geochemical precursors detection of precursory phenomena in observation data is essential to earthquake prediction studies continuous monitoring of radon concentration in groundwater in japan in one case showed a short term anomaly related to a nearby earthquake with the exception of the 1978 izu oshimakinkai earthquake m7 0 however no abnormal change has been noted this may be due partially to difficulty in detecting insignificant precursory signals from observation data which ordinarily contains a noise induced fluctuations and partially to lack of understanding of the mechanism controlling the appearance of precursory phenomena in order to increase our knowledge of the variation pattern of precursory changes in radon concentration of groundwater hydrologic precursors with significant features are examined in this paper complexity of appearance of precursory phenomena and problems in assignment of the specific earthquake are discussed

palynological evidence for late quaternary warming episodes in southern africa abstract polleniferous sediments from southern africa associated with past warm episodes before the last glacial maximum are rare interpretation of environmental conditions during these phases are complicated by difficulties of dating in sediments from the northern areas north of 28 s the prominence of tropical woodland pollen suggests that the period between 7000 and 6500 yr b p was associated with optimal temperatures during the holocene identifying the warmest phase in the southern high lying grasslands and semi arid karoo shrublands south of 28 s is difficult because unlike the savanna areas of the north they do not yield good pollen indicators for changes in temperature such as those of frost sensitive trees however some pollen sequences from further south along the southern coast of africa 34 s and at marion island in the southern ocean 47 s suggest that the holocene temperature optimum occurred at about the same time in the sub antarctic area in the south and the subtropical regions in the north the advent of moister conditions in southern africa during the early to middle holocene is generally recorded earlier ca 7500 6500 yr b p in the north at ca 26 s than around 31 s ca 5000 yr b p this change is provisionally associated with a relative shift in seasonality from a predominance of all season precipitation to a greater proportion of summer rainfall which apparently reached the southern karoo areas two thousand years later than the northern bushveld region

the leaf wax biomarker record of a namibian salt pan reveals enhanced summer rainfall during the last glacial interglacial transition abstract conventional continental geoarchives are rarely available in arid southern africa therefore palaeoclimate data in this area are still patchy and late quaternary climate development is only poorly understood in the western kalahari salt pans playas ephemeral lakes are common and can feature quasi continuous sedimentation this study presents the first climate related biomarker record using sediments from the omongwa pan a kalahari salt pan located in eastern namibia our approach to reconstruct vegetation and hydrology focuses on biogeochemical bulk parameters and plant wax derived lipid biomarkers n alkanes n alkanols and fatty acids and their compound specific carbon and hydrogen isotopic compositions the presented record reaches back to 27 ka during the glacial rather low 2h values of n alkanes and low sediment input exclude a strong influence of winter rainfall n alkane and n alkanol distributions and 13c values of n hentriacontane n c31 indicate a shift to a vegetation with a higher proportion of c4 plants at the end of the last glacial maximum until the end of heinrich stadial i ca 18 14 8 ka which we interpret to indicate an abrupt excursion to a short wetter period likely to be caused by a temporary southward shift of the intertropical convergence zone shifts in 2h values of n c31 and plant wax parameters give evidence for changes to drier conditions during early holocene comparison of this dataset with representative continental records from the region points to a major influence of summer rainfall at omongwa pan during the regarded time span and demonstrates the potential of southern african salt pans as archives for biomarker based climate proxies

second round of evaluations of proposed earthquake precursors this review summarizes the result of the second round of nominations for the iaspei preliminary list of significant precursors currently this list contains five cases of precursors 1 foreshocks 2 preshocks 3 seismic quiescence before major aftershocks 4 radon decrease in ground water and 5 ground water level increase a list of four cases that could not be accepted nor rejected by the panels reviewing them contains three on crustal deformations and one on seismic quiescence in the second round 10 nominations were evaluated nine new ones and one which had been considered previously two were accepted for the list two were placed in the category of undecided cases to date a total of 40 nominations have been evaluated by iaspei for 37 of these the nominations the mail reviews the panel opinions and where supplied the author s reply were published this evaluation process remains active throughout the international decade for natural hazards reduction additional nominations are invited

grassland development under glacial and interglacial conditions in southern africa review of pollen phytolith and isotope evidence abstract pollen evidence suggests that grasslands were well established in southern africa by the late tertiary evidence for grassland composition in the region during the quaternary includes published accounts of isotopes grass phytoliths and pollen of both grasses and woody plants from a wide range of different environments isotope data were derived from speleothems stalagmites fossil bones and fossil tooth enamel and plant material in fossil hyrax dung the different data types suggest that with perhaps the exception of the dry southern kalahari region temperate grassland consisted of a relatively increased c3 to c4 grass ratios during the last glacial maximum lgm cold winter temperature extremes in the southern high latitude and altitude regions and a persistent winter rainfall pattern over the cape region during the lgm probably limited the distribution of c4 grasses and canceled out any advantages gained from lowered co2 concentrations in the atmosphere in contrast in the tropics where marked seasonal temperature fluctuations were lacking c4 grass growth was favored

groundwater ion content precursors of strong earthquakes in kamchatka russia the kamchatka peninsula located in the far east of russia is a geologically active margin where the pacific plate subducts beneath the north american and eurasia plates this area is characterised by frequent and strong seismic activity magnitudes reaching 8 6 and epicentres are generally distributed offshore along the eastern coast of the peninsula for many years hydrogeochemicals have been sampled with a mean interval of three days to measure the most common ions in the groundwater of five deep wells in the southern area of the kamchatka peninsula in the last decade five earthquakes with m 6 5 have occurred at distances less than 250 km from these wells these earthquakes were powerful enough for them to be considered as potential originators of precursors in order to reveal possible precursors of these earthquakes we analysed the groundwater ion contents the quasi periodic annual variation was filtered out together with other slow trends and then we smoothed out the high frequency fluctuations that arise from errors in a single measurement when examining the data we labelled each signal with an amplitude greater than three times the standard deviation as an irregularity and we made a first attempt at defining an anomaly as an irregularity occurring simultaneously in more than one parameter at each well in a second definition we used the existence of an irregularity occurring simultaneously in each ion at more than one well then on the basis of past results worldwide and the time interval between the earthquakes observed we chose 158 days as the maximum temporal window between a possible anomaly and the subsequent earthquake with the first anomaly definition we identified 6 anomalies with 4 possible successes and 2 failures for the five earthquakes considered capable of producing precursors we obtained precursors in three cases with the second anomaly definition we identified 10 anomalies with 7 possible successes and 3 failures and we obtained precursors in four of the five earthquakes a schematic model explaining aspects of the complex relationship linking earthquakes and ion content anomalies is also presented

identification of anomalous radon concentrations due to geodynamic processes by elimination of rn variations caused by other factors summary it has been suggested that temporal variations of radon rn concentrations in various media may be used as a possible predictive indicator of seismic activity however observed rn measurements are a function of a number of diierent physical processes including seismic activity this paper describes a generalized approach to removing noise components from the observed data to leave a residual component of radon concentration that re ects geodynamic processes at depth the approach is demonstrated using data gathered in israel at the time of the 1992 october 12 giza earthquake in egypt

the kashiru pollen sequence burundi palaeoclimatic implications for the last 40 000 yr b p in tropical africa abstract a continuous pollen record from a central african highland site 3 28 s 29 34 e with 15 radio carbon dates spans at least the last 40 000 yr both modern and fossil pollen have been investigated a clear pattern of changes in vegetation and climate is suggested prior to 30 000 yr b p the occurrence of the montane conifer forest including the upper forest limit indicates climatic conditions colder and drier than now but more humid than in late glacial time between 30 000 and 15 000 yr b p grassland with afroalpine indicators expanded down to 2500 2000 m altitude as a result of dry and most probably cool climate the montane forest persisted in refuges although much reduced forest vegetation with the same floristic composition as today appeared after 13 250 200 yr b p suggesting more humid conditions the occurrence of a possible short term humid episode about 21 500 yr b p is correlated with some high lake level stages in east africa and with organic deposits in deep sea cores from the mediterranean and the atlantic ocean

release of mantle and crustal helium from a fault following an inland earthquake abstract static stress changes caused by megathrust slip of the 2011 mw 9 0 tohoku oki earthquake considerably affected the seismicity patterns in inland areas resulting in the occurrence of numerous earthquakes along several active faults in japan on june 30 2011 the mj 5 4 central nagano earthquake occurred at a shallow depth of 5 km indicating the reactivation of the gofukuji fault in central japan this study was undertaken to elucidate spatial and temporal changes of 3he 4he ratios around a source region before and after an inland earthquake using both existing and new and helium isotope data from hot spring and drinking water wells gas samples near the gofukuji fault and its surrounding active faults are characterized by an increase in postseismic 3he 4he ratios in contrast the postseismic ratios decreased by up to about 30 away from the mainshock epicenter episodic faulting could either release stored crustal radiogenic helium from host rocks or enhance the transfer of mantle volatiles through permeable fault zones such that subsequent fluid flow near to the source region could then explain the spatio temporal variations in 3he 4he ratios

precursory and coseismic groundwater temperature perturbation an example from taiwan abstract we have conducted taiwan s first groundwater temperature earthquake precursory and coseismic signal study using totally 8 month time series of groundwater temperature from two monitoring wells in eastern taiwan we applied hilbert huang transform hht analysis to identify possible precursory signals with periods ranging from one to ten minutes and duration of tens of hours that occurred one to three days before mw 4 7 earthquakes these signals are not correlated with atmospheric and pumping processes the precursors are sensitive to an earthquake within an epicentral distance that is about 20 to 25 time of the earthquake rupture length with this limited dataset we found the rates of false positives and false negatives are 16 7 and 28 6 respectively exact physical processes that generate such signals are unclear and additional data are needed but we propose that real time groundwater temperature monitoring has potentials to become a low cost but beneficial way to complement other earthquake precursory projects for more robust short term earthquake forecasting

assesment of the response of the meteorological hydrological parameters on the soil gas radon emission at hsinchu northern taiwan a prerequisite to identify earthquake precursors abstract the present study is an attempt to assess and quantify the influence of the meteorological atmospheric temperature and pressure and hydrological rainfall and ground water head gwh parameters on the soil gas radon emission at hsinchu northern taiwan the quasi periodic variations corresponding to diurnal and semi diurnal periods were estimated and eliminated by decomposing the time series for the period of september 16 2009 to march 5 2010 to singular spectrum analysis the reconstructed non periodic variations which reproduce the salient feature of recorded time series were searched for meteorological hydrological influences in radon emission the combined response of barometric pressure and atmosphere temperature are found to be small when compared to the total variability in radon the influence of rainfall on radon is found to be strongest at the onset of rainfall radon shows a step jump that attains peak with a time lag of 12 15 h this enhancement is attributed to entrapment of soil gas in the top soil cover as increased soil moisture prevents escape of radon into the atmosphere capping effect the decay of radon after the recession of rainfall is approximated by double exponential decay terms one corresponding to the natural decay of radon with half life of 3 84 days and second representing slow weakening of capping effect the third effect related to internal loading due to rise and fall of groundwater modulates the propagation of radon in overlying strata accounting for the long term variations in radon the rainfall inflicted changes in radon look strikingly similar to earthquake related precursory or co seismic perturbations inferred by long term synotopic observations it is surmised that unless radon variations are corrected for meteorological hydrological contamination some precursory signals are masked on one hand while on the other hand some anomalies are falsely viewed as earthquake precursors

isotopic analysis of equid teeth from wonderwerk cave northern cape province south africa abstract stable carbon and nitrogen isotope ratios have been determined from equid teeth from a well dated sequence of holocene deposits at wonderwerk cave situated in a summer rainfall area of the northern cape province of south africa stable carbon isotope ratios confirm the existence of a c 4 grassland habitat throughout the holocene nitrogen isotope ratios are assessed in relation to data from modern equid samples from southern africa temporal variability in both carbon and nitrogen isotope ratios of holocene equid samples from wonderwerk appears to be analogous to spatial variability of such ratios determined for faunal samples from modern environments relationships between isotope ratios and data from modern environments are used to obtain rainfall indices

pollen analysis of hyena coprolites and sediments from equus cave taung southern kalahari south africa equus cave in quaternary tufa near taung in the semiarid woodland of the southern kalahari yielded 2 5 m of sediment in which a rich assemblage of bones and coprolites was preserved the fossils were accumulated mainly by hyenas during the late pleistocene and holocene pollen from coprolites reflects diet as well as vegetation over relatively large areas visited by hyenas while pollen from sediments represents more local sources the pollen sequence derived from coprolites and sediments demonstrates how the vegetation evolved from open grassland with small shrubs and occasional trees during the late pleistocene to open savanna with more small shurbs then during the last 7500 yr to modern savanna temperatures were not more than 4 c cooler and it was slightly moister than today during the late pleistocene phase it became gradually warmer but relatively dry before optimal temperature and moisture conditions developed around 7500 yr b p climatic conditions slightly less favorable for woodland occurred during part of the late holocene

geochemical patterns of groundwater from the palomares carboneras active fault area aquifers se spain determination of a network of sensitive sites indicators of seismic events the aim of this study is to evaluate the hydrogeochemical parameters of the palomares carboneras active fault zones se spain aquifers to establish especially sensitive sampling points that could be indicators of seismic activity in the fault zone we consider these points as a part of a network for this fault area and others in the south of spain with a seasonal and or continuous sampling in the future that may allow us to provide advices of possible seismic events the eastern part of the betic cordillera is a mediterranean semi arid zone with a special sensitivity to climatic fluctuations and human activity a remarkable scarcity in water resources is evident in this region making it difficult to find groundwater sampling points subsequently a network has been designed with 33 water sites selected for availability and proximity to the active fault zones where the physical chemical features and isotope contents of the groundwater have been determined taking into account the geological complexity as well as the different hydrogeological paths recognized in the area three geochemical families of water have been found 1 water with high electrical conductivity up to 14 000 s cm temperatures above 20 c and in some cases traces of boron 2 water with medium electrical conductivity 2 000 3 500 s cm temperatures above 20 c and traces of boron 3 water with electrical conductivity below 1 000 s cm temperatures below 20 c and absence of boron high temperature waters with presence of boron were selected as indicators of deep water circulation processes that can be connected to the seismic activity of the palomares carboneras active fault zones according to this study a selected sensible warning aquifer sites has been established

a late quaternary pollen record from the transvaal bushveld south africa pollen spectra from cores of organic spring deposits from the transvaal provide evidence for the climatic evolution of the province during the last 35 000 yr b p or more the past climatic phases are derived from palynological reconstructions of past vegetation types by comparison of fossil pollen data with modern surface pollen spectra from various localities evidence is provided for an early moist cool phase with relatively mesic bushveld and expanded montane forest in the central transvaal followed by a drier period with drier bushveld which probably lasted until approximately 25 000 yr b p during the next phase which at the latest ended about 11 000 yr b p the temperatures were probably 5 6 c cooler than at present at that time bushveld vegetation in the central transvaal was replaced by open grassland with macchia elements climatic amelioration came and semiarid savanna returned to the plains at first gradually and then developing into a warm kalahari thornveld type vegetation after 6000 yr b p it apparently became slightly wetter and a more broad leafed bushveld developed about 4000 yr b p it again became cooler and slightly wetter and the bushveld vegetation on the central and northern plains was comparable to present open upland types after 2000 yr b p conditions gradually became warner until about 1000 yr b p when the modern climate of the central transvaal bushveld originated

a late quaternary record of monsoon variability in the northwest kimberley australia abstract understanding of the late quaternary environment of australia s vast kimberley region has to date been hindered by the region s lack of classic palaeoenvironmental archives such as deep lake sediments however mound spring peat deposits in the region have been found to be a potentially rich archive of palaeoenvironmental data here we present a high resolution record from black springs mound spring in the kimberley s northwest filling some of the current gaps in knowledge of the region s environmental history this builds on a 6000 year record developed from the same site and indicates that since the last glacial interglacial transition the australian summer monsoon has varied greatly in intensity with an increase in monsoonal precipitation from 14 000 yr bp and pronounced drying in the late holocene despite some chronological uncertainties thought to be due to the inclusion of younger microscopic root fragments changes in the record compare well with other records of climatic change from the kimberley and across tropical northern australia

fossil hyrax dung and evidence of late pleistocene and holocene vegetation types in the namib desert abstract pollen was derived from fossil dung of herbivorous hyraxes deposited in a rock shelteron the highest mountain in namibia da ures or brandberg situated on the namib desert margin radiocarbon dating ranging in age between modern times and 30000yrbp showed it representsthe rst empirical pollen evidence of continental palaeovegetation during the late pleistocene alongthe western escarpment of southern africa the initial results indicate last glacial maximum vegeta tion differed totally from the current pattern as vegetation types were dominated by small asteraceaeshrubs in contrast to those of the holocene and modern times which show more succulents grassandwoody elements arboreal pollen the resultssuggest that cape oral communities didnot reachinto thetropics along thewestern escarpment ofafrica despite such pollentypes occurring inmarinecores copyright 2004 john wiley sons ltd keywords palynology namibia restionaceae late pleistocene last glacial maximum

african hydroclimatic variability during the last 2000 years abstract the african continent is characterised by a wide range of hydroclimate regimes ranging from humid equatorial west africa to the arid deserts in the northern and southern subtropics the livelihoods of much of its population are also vulnerable to future climate change mainly through variability in rainfall affecting water resource availability a growing number of data sources indicate that such hydroclimatic variability is an intrinsic component of africa s natural environment this paper co authored by members of the pages africa 2k working group presents an extensive assessment and discussion of proxy historical and instrumental evidence for hydroclimatic variability across the african continent spanning the last two millennia while the african palaeoenvironmental record is characterised by spatially disjunctive datasets with often less than optimal temporal resolution and chronological control the available evidence allows the assessment of prominent spatial patterns of palaeomoisture variability through time in this study we focus sequentially on data for six major time windows the first millennium ce the medieval climate anomaly 900 1250 ce the little ice age 1250 1750 ce the end of the lia 1750 1850 ce the early modern period 1850 1950 and the period of recent warming 1950 onwards this results in a continent wide synthesis of regional moisture balance trends through history allowing consideration of possible driving mechanisms and suggestions for future research

earthquake related elemental and isotopic lead anomaly in a springwater abstract elemental and isotopic analyses of lead present at ultra trace levels were obtained with a double focusing inductively coupled plasma mass spectrometer on a pyrenean springwater the sampling was carried out across a time series of 598 days encompassing an earthquake of magnitude 5 2 lead concentrations show a tenfold increase and isotopic compositions shift toward anthropogenic values four days prior to the quake the time lag between these geochemical anomalies and the earthquake combined with hydrogeological constraints are then used to infer where and when strain changes during earthquake preparation processes went beyond the threshold required to temporarily mix waters from normally independent aquifers the occurrence of pre seismic centrifugal strain waves propagating from the epicenter area is proposed on the basis of the observed geochemical anomalies

implicit randomness in earthquakes 1 analytical number theory for two integers chosen at random provides a numerical method to estimate value an analysis of three datasets of earthquakes including earthquakes occurring in mainland china south california and all over the world thus allowed us to estimate with less than 3 0 relative deviation the complexity of earthquakes is expressed by implicit randomness and characteristics of seismicity if other physical precursors were not taken into account two or more earthquakes would be correlative with one another or an earthquake could be partly predictable on the basis of the event sequence itself with a ratio of about 40 at most

holocene palynology and palaeoenvironments in the savanna biome at tswaing crater central south africa abstract a radiocarbon dated pollen and microscopic charred particle record from the holocene section of the tswaing crater in the savanna biome of south africa give new evidence for environmental changes during the period c 9400 1800 cal years bp pollen grains are scarce or absent in layers dating from before 9400 cal years bp but deposits rich in pollen occur in overlying layers the section dated between 9400 cal years bp and c 7200 cal years bp contains grass asteraceae and dry savanna pollen types that suggest fluctuating but generally dry moisture conditions later between c 7200 and 1800 cal years bp broad leaved savanna woodland elements and local swamp pollen indicate relatively stable vegetation and wetter mildly fluctuating climatic conditions which is consistent with previously published biomarker analysis between c 6200 and 5500 cal years bp the numbers of charred particles increased slightly this indicates burning activity which can probably be attributed to dry season ignition of denser fuel under relatively moist conditions a decrease of local swamp pollen between c 3600 and 3500 cal years bp suggests that conditions became briefly drier again as pollen of woody elements declined in favour of open grassland pollen a comparison between the tswaing pollen profile and various other sequences within the central interior of south africa suggests generally similar conditions over the central interior of the sub continent during the holocene deviating from sequences further afield along the coastal areas of southern africa between 9400 cal years bp and ca 7200 cal years bp the western and southern coasts were probably controlled by different atmospheric and oceanic circulation regimes under the influence of a strong westerly winter rain system while the north eastern area where tswaing is situated experienced weaker precession and less summer rain from the intertropical convergence zone

radon emissions from mud volcanoes in northern italy possible connection with local seismicity data concerning radon emission in waters filling mud volcanoes of northern apennines northern italy sampled from 1986 until 1989 have been analyzed possible connections between shallow environmental conditions and rn emission from mud volcanoes have been explored a linear relationship between air temperature and rn count rates has been determined after the removal of temperature related rn variations a significant correlation has been pointed out between anomalous spike like rn emissions at one of the station considered and the occurrence of low magnitude m 4 5 local earthquakes

pollen indications of holocene palaeoenvironments at florisbad spring in the central free state south africa mid to late holocene pollen data from florisbad in the central free state south africa reveal a number of moisture fluctuations commencing at c 6500 bp the pollen sequence indicates an arid climate but shows more availability of moisture under grassy conditions from summer rain at c 6300 bp and again at c 4420 bp the interval between these dates is characterized by a dry episode with karroid shrubs some time between 5500 and 4500 bp possibly as a result of less marked summer seasonality after 4220 bp moisture conditions gradually fluctuated in intensity or seasonal availability until c 2100 1700 bp when strong summer evaporation is indicated at the upper end of the sequence the data are complemented by previously published results on environmental change from the nearby deelpan site to the west although some distinct events correlate regionally over south africa summer rains appear to have been significant at florisbad at an earlier stage in the mid holocene than in the karoo to the south

slip rate increase at parkfield in 1993 detected by high precision edm and borehole tensor strainmeters on two of the instrument networks at parkfield california the two color electronic distance meter edm network and borehole tensor strainmeter btsm network we have detected a rate change starting in 1993 that has persisted at least 5 years these and other instruments capable of measuring crustal deformation were installed at parkfield in anticipation of a moderate m6 earthquake on the san andreas fault many of these instruments have been in operation since the mid 1980s and have established an excellent baseline to judge changes in rate of deformation and the coherence of such changes between instruments the onset of the observed rate change corresponds in time to two other changes at parkfield from late 1992 through late 1994 the parkfield region had an increase in number of m4 to m5 earthquakes relative to the preceding 6 years the deformation rate change also coincides with the end of a 7 year period of sub normal rainfall both the spatial coherence of the rate change and hydrological modeling suggest a tectonic explanation for the rate change from these observations we infer that the rate of slip increased over the period 1993 1998

late quaternary peat accumulation in southern africa abstract it is suggested that the accumulation of peat deposits and other organic sediment may be a clue to the timing of moister periods in the late quaternary climatic history of southern africa data presented from 26 sites across the sub continent point to two periods during which organic sedimentation commenced suggesting a moister late pleistocene and a period during the mid late holocene when conditions also became more conducive to peat formation owing to the confusing and conflicting nature of other palaeoenvironmental information organic sediment accumulation chronologies seem to provide additional insight into the environmental history of southern africa and the implications of this are discussed

recent results of hydrogeochemical studies for earthquake prediction in the ussr the paper reviews the chief results of the hydrogeochemical and hydrogeodynamic investigations conducted for earthquake prediction in all seismic regions of the ussr

barrier fronted saltponds cape cod usa and limans nw black sea ukraine comparative morphostratigraphy and response to sea level rise abstract microtidal saltponds of the upper cape cod ma usa and the limans of the non tidal northwestern black sea are compared on the basis of their planimetric and barrier stratigraphic characteristics the shore normal ellipticity value e n is defined as a means of distinguishing between shore normal valley type and shore parallel lagoon type trending water bodies in addition to quantifying their overall morphology besides the differences in morphological response to relative sea level rise of the bays with different e n values greater impact of barrier retreat on bays with lower e n the size of the water bodies and barrier width and height are important factors in determining their response given simple landward barrier translation an average liman with e n 0 8 will have a 50 reduction in open water area over approximately 1000 years whereas less than 10 decrease is predicted for valley type systems e n 0 8 over the same time interval similar retreat will take place in just 300 years for saltponds although relative sea level is rising at a slower rate along the south shore of cape cod than along nw black sea it is expected to have a greater impact on saltpond water area reduction due to their smaller sizes and narrower barriers engineering structures make it difficult to predict the near future behavior of individual coastal segments storm driven flooding overwash and breaching of narrow and low barrier segments will be the likely morphodynamic response at both sites

microscopic charcoal in sediments quaternary fire history of the grassland and savanna regions in south africa the microscopic charcoal content of several quaternary pollen sequences is used to investigate fire history in south africa both during the holocene and the late pleistocene although fluctuations in charcoal composition are recorded it is difficult to link them directly to either human made or natural fires strong long term variations in microscopic charcoal of middle and upper pleistocene layers are independent of pollen indications of past temperature and moisture conditions holocene charcoal sequences from different areas show no correlation so no phases of regional burning are found some fluctuations in charcoal probably are the result of local burning in the various regions the arrival of iron age people some 2000 yr ago apparently did not coincide with widespread wild fires as these events do not consistently appear in regional microscopic charcoal records the only exception appears to be the wonderkrater spring deposit relatively open savanna environments which are implied by pollen analysis at some sites during this period and the generally low microscopic charcoal contents were either caused by climate change or controlled burning by iron age people copyright 2002 john wiley sons ltd

a revised 30 000 year paleoclimatic and paleohydrologic history of lake albert east africa abstract new geochemical and palynological data and a sedimentological reinterpretation of two cores from lake albert allow a revision of the paleoclimatic and paleohydrologic history of northwest uganda over the last 30 000 14 c yr bp our findings document one and possibly three periods of significantly reduced inflow to the nile river system from the white nile based on sediment fabric and mineralogy shifts in percentages of total organic carbon toc and total organic nitrogen ton hydrogen index hi and 13 c and 15 n as well as poor preservation of sporopollenin and siliceous microfossils we recognize two mature paleosols that formed between 18 000 and 12 500 14 c yr bp at the surface of exposed lacustrine muds a thin fossiliferous zone between the two soils documents a brief period of flooding lake albert was below the level of the coring site and thus a closed basin for several thousand years during the late pleistocene around 12 500 14 c yr bp the younger vertisol was flooded by a major rise in lake level relatively deep water conditions were established soon after this transgression but an apparent change in sedimentation rate sometime between 8 000 and 3 400 14 c yr bp may reflect another briefer period of low water which resulted in interruption of sedimentation at the coring site palynological data document a rapid and abrupt shift to drier conditions around lake albert from 11 400 to 9 900 14 c yr bp coincident with the cool younger dryas event of the northern hemisphere geochemical evidence suggests that throughout the terminal pleistocene and early holocene and again in the late holocene the water column was relatively well mixed with little tendency to persistent anoxia

geothermal investigations in an area of induced seismic activity northern sao paulo state brazil abstract geothermal investigations were carried out in nuporanga state of sao paulo brazil where occurrence of seismic activity has been found to be closely related to opening of groundwater wells results of macroseismic studies show that seismic activity had its beginning in may 1977 soon after completion of drilling of the colaba well and most of the initial seismic events are located close to it geothermal investigations were initiated in september 1977 on the assumption that fluid movements associated with seismic activities are capable of producing short term time dependent changes in the local thermal regime and in the hope that identification of such time dependent changes would contribute to a better understanding of the nature of local seismicity results of thermal logs in the colaba well reveal the existence of an unusual thermal regime with a constant temperature zone ctz down to 175 m followed by a zone in which temperature rises rapidly tgz in the interval of 180 204 m repeated thermal logs carried out over a period of three months reveal temperature drops of up to 0 8 c taking place in the tgz immediately after periods of intense microseismic activity temperature measurements of pumped water also show changes of lesser magnitude occurring in the ctz closely related to the frequency of seismic events substantial temperature changes related to periods of seismic activity were also observed in two nearby wells in nuporanga the available geothermal and macroseismic data have been used in the development of a simple model of the process that have triggered seismicity in nuporanga according to this model the colaba well acts as a natural siphon drawing water from a perched aquifer at depths of less than 40 m and injecting it to a fault zone at about 175 m the model allows a coherent explanation for the observed correlation between seismicity and absence of pumping during periods in which pumping is suspended the static level of water in the well is high and the pressure exerted by the water column induces a reduction in frictional resistance at the fault zone during pumping the water level falls to its dynamic level and consequently the pressure at the fault zone is also lower such pressure changes are apparently sufficient to trigger microseismic activity in nuporanga the observed temperature drops immediately after tremors could be attributed to the cooling effect associated with the penetration of relatively cold water from upper levels into newly opened fractures also the small but significant rise in temperatures during seismically quiescent periods can be considered as a result of warming up of stationary fluid bodies within fracture zones measures taken on the basis of this model has been successful in switching off seismicity on at least two occasions in view of this success we conclude that geothermal investigations can be of considerable use in understanding the nature of fluid movements associated with near surface earthquakes

geochemical monitoring in the marmara region nw turkey a search for precursors of seismic activity 1 physical and chemical properties of warm and hot spring waters as well as soil radon concentrations were measured continuously during a 3 year period in the marmara region following the devastating izmit earthquake of 17 august 1999 mw 7 4 promising and encouraging anomalies in ground radon emanation have been recorded and found to be closely related to seismic activity the temporal and spatial variations in the soil radon data are presented the earthquakes with magnitude 4 in the region were correlated with positive radon anomalies furthermore during quiescence absence of seismic activity the radon data indicate random walk behavior of radon in soil and show rayleigh type probability density function pdf however during the earthquake build up period the data show deviations from rayleigh type pdf the radon positive anomalies indicate disturbance of the path of gas movement or gas release pattern prior to earthquakes however systematic and consistent anomalies in physical and or chemical properties of the spring waters have not been detected for earthquakes occurring in the observation period m 5 3

gas geochemistry and seismotectonics a review abstract publications on soil and spring gases have been examined regarding their relationships with both tectonic and seismic activities the main sources behaviours and uses of species detected in soils and springs are displayed and their mode of sampling and analysing briefly described the main patterns of degassing in soils are described and we outline the wide range of geochemical signatures as the result of both permeability and mineralogical contrasts because thermomineral waters have been in contact with great volumes of crustal rocks at various depths spring gases might be more representative of the local environment than soil gases moreover gas signature comparisons show that spring gases are much more enriched with deep gases and slightly contaminated by atmospheric gases therefore they can be considered as better samples for identifying precursors of earthquakes environmental perturbations are examined and it is shown from divergent cases that pressure temperature soil moisture or earth tides may generate very high perturbations of the degassing process such effects demonstrate that no systematic correction law can be proposed and that removing external contributions from gas concentrations must be performed case by case this demonstrates therefore the need for the simultaneous measurement of external parameters during gas monitoring a qualitative examination of about 150 claimed precursors proposed in the literature has been reviewed as noted by previous authors anomalies appear at distances sometimes much greater than typical source dimensions and occur in the field of strain higher than 10 9 most of them being in the field of strain higher than 10 8 taking into account the very high heterogeneity of such a set of data we can suggest that amplitudes of gas anomalies are independent of both magnitudes and epicentral distances of related earthquakes suggesting local conditions to control amplitudes on the contrary precursory time and duration of anomalies seem to increase both with magnitudes and epicentral distances abundant evidence demonstrates the major role of crustal fluids in the earthquake cycle many works have outlined the fact that crustal instabilities can appear as the result of low stress strain perturbations during loading it has been suggested that motion of fluids may occur at various scales from microcrack fluid transfer up to changes of hydraulic levels of water tables the study of subsequent anomalies is expected to supply a tool for earthquake prediction following previous authors we outline the need for further methodological improvements including the setting up of multiparameter station networks and the simultaneous recording of the main external parameters atmospheric pressure water and air temperature soil moisture for signal processing

earthquake prediction a critical review summary earthquake prediction research has been conducted for over 100 years with no obvious successes claims of breakthroughs have failed to withstand scrutiny extensive searches have failed to find reliable precursors theoretical work suggests that faulting is a non linear process which is highly sensitive to unmeasurably fine details of the state of the earth in a large volume not just in the immediate vicinity of the hypocentre any small earthquake thus has some probability of cascading into a large event reliable issuing of alarms of imminent large earthquakes appears to be effectively impossible key word earthquake prediction

a 22 kyr bp sedimentological record of lake rukwa 8 s sw tanzania environmental chronostratigraphic and climatic implications abstract the sedimentological study of a 12 8 m long core r96 i from lake rukwa tanzania 8 s provides a new record of past lake level fluctuations that took place in response to changes of the regional climate since the last glacial period from 21 to 15 cal kyr bp nearshore and swamp marsh environments are evidenced from clastic deposition macrophytes debris and ca mg carbonate enrichments a transgressive sequence starting around 15 cal kyr bp lead to the humid lacustrine optimum between 15 and 7 cal kyr bp from 12 to 10 cal kyr bp anoxic lake bottom environments were favored by the concomitant effects of high primary productivity increased subsidence and inputs of volcanic ash in the lake the middle holocene 7 3 cal kyr bp is characterized by high concentrations of silt carbonates and low organic content which indicate the occurrence of relatively oxic shallow and saline depositional environments especially around 7 and 3 4 cal kyr bp although grainsize and toc profiles suggest that shallow environments likely persisted in the upper holocene low mg concentration values for the last 3 kyr may indicate a trend toward relatively more dilute environments the two main lake rukwa low stand periods at 21 15 and 7 3 cal kyr bp correspond remarkably well with the insolation maximum at the equator which occurred at 17 kyr bp for the spring equinox and at 6 kyr bp for the autumn equinox respectively we suggest that during these periods of minimum inter hemispheric insolation gradients monsoon circulation weakened in south equatorial regions and the itcz was located north of 8 s in east africa

simulated climate and biomes of africa during the late quaternary comparison with pollen and lake status data new compilations of african pollen and lake data are compared with climate ccm1 ncar boulder and vegetation biome 1 2 gsg lund simulations for the last glacial maximum lgm and early to mid holocene emh the simulated lgm climate was ca 4 c colder and drier than present with maximum reduction in precipitation in semi arid regions biome simulations show lowering of montane vegetation belts and expansion of southern xerophytic associations but no change in the distribution of deserts and tropical rain forests the lakes show lgm conditions similar or drier than present throughout northern and tropical africa pollen data indicate lowering of montane vegetation belts the stability of the sahara and a reduction of rain forest the paleoenvironmental data are consistent with the simulated changes in temperature and moisture budgets although they suggest the climate model underestimates equatorial aridity emh simulations show temperatures slightly less than present and increased monsoonal precipitation in the eastern sahara and east africa biome simulations show an upward shift of montane vegetation belts fragmentation of xerophytic vegetation in southern africa and a major northward shift of the southern margin of the eastern sahara the lakes indicate conditions wetter than present across northern africa pollen data show an upward shift of the montane forests the northward shift of the southern margin of the sahara and a major extension of tropical rain forest the lake and pollen data confirm monsoon expansion in eastern africa but the climate model fails to simulate the wet conditions in western africa

microplate boundaries as obstacles to pre earthquake strain transfer in western turkey inferences from continuous geochemical monitoring abstract warm and hot spring water chemistry changes as well as soil gas radon release patterns have been monitored in western turkey alongside regional seismicity providing a multi disciplinary approach from january 2009 to may 2011 33 earthquakes with ml between 4 0 and 6 0 occurred in this seismically very active region the ml 6 0 earthquake occurred on 19 may 2011 in simav town of kutahya province at a location midway between dense multidisciplinary monitoring networks of marmara region mr and the aegean extensional province aep we previously reported on noteworthy precursory anomalies prior to several earthquakes ml 4 in the mr and aep but no precursory anomaly was detected prior to the ml 6 0 event on 19 may 2011 in simav kutahya province midway between dense multidisciplinary monitoring mr and aep networks although these networks operate within the theoretical strain radii of this earthquake dobrovolsky et al 1979 no reliable anomaly were found geodetic studies based on gps data have identified crustal blocks in this region the epicentral area of the simav event is located within a block tectonically separated from aep and mr thus we speculate that pre earthquake strain accumulation within the simav block did not effectively transfer to adjacent blocks where the mr and aep networks are located thereby providing an explanation for the absence of detectable anomalies moreover prior to some earthquakes quadrant features of geochemical transients have been found suggesting that soil radon anomalies appear in compressional quadrant s of pre earthquake strain distribution

pollen in fossil hyrax dung from marine isotope stages 2 and 3 reveals past environments in namibia abstract in view of a scarcity of terrestrial quaternary pollen records relating to climate change in desert areas we present new terrestrial sequences from hyrax middens in namibia while the few previously available pollen records are mainly holocene we present climate time series for marine isotope stages 2 and 3 mis 2 and mis 3 the data are from two sites in central namibia that are surrounded by desert plains and close to the namibian escarpment viz the d ures massif brandberg and 200 km further south the mirabib shelter located in a small inselberg in the studied material grass rich pollen assemblages were more common at mirabib where the vegetation is desert grassland than at brandberg with its mountain vegetation hyrax radiocarbon ages range from 21 ka to 50 ka with inconsistencies in ages near the limit of effective radiocarbon dating however correlation of overlapping sequences supports the chronology we present despite chronological gaps in the available deposits pollen assemblages from different middens indicate marked climate cycles starting with moderately cool dry conditions with grassy karroid vegetation at mirabib c 50 ka after a gap in the record warmer conditions with savanna woodland are indicated at both mirabib and brandberg around 40 ka eventually cool conditions supporting shrubby grassland with wild olives developed at brandberg during mis 2 c 21 ka comparison with marine pollen data confirms earlier findings that terrestrial pollen assemblages differ markedly from south atlantic ocean marine pollen assemblages of the same age presumably due to mixing of pollen from wide source areas at the marine localities versus the more locally restricted terrestrial pollen sources trapped in hyrax dung the results therefore add information for the interpretation of local vegetation shifts on land during the interval between 50 ka and 21 ka in namibia

preseismic changes in groundwater level and volumetric strain associated with earthquake swarms off the east coast of the izu peninsula japan we have observed the groundwater level at omuroyama kita omr well on the izu peninsula japan since october 1994 during the observation period there were four earthquake swarms we detected one or two preseismic groundwater level changes together with preseismic crustal deformation recorded at the other nearby stations therefore those preseismic groundwater level changes are considered to be caused by crustal deformation or volumetric strain changes the crustal deformations are inferred to be caused by the magmatic dike intrusion which is a possible source of the earthquake swarms off the east coast of the izu peninsula

co2 and radon measurements in the vogtland area germany a contribution to earthquake prediction research the interpretation of long term radon measure ments in a spring located in vogtland shows a significant relationship to the seismicity of a region close to the sampling point a statistical check was performed in order to identify the anomaly generating area the cause for this relation is emission of mantle originated gases including co2 influenced by tectonic processes in the crust

rock as a critical point system and the inherent implausibility of reliable earthquake prediction summary the statistical mechanics of critical point thermodynamic systems provide a powerful conceptual tool with which to examine the plausibility of reliable earthquake prediction the issue turns on how rock is heterogeneous if the correlation range of a spatially fluctuating rock property is bounded by a characteristic length then the spatial average of that property over dimensions greater than may be regarded as defining an effective continuum value for that property ideas about earthquake preparation in rock with an effective continuum mechanical strength can plausibly focus on failure that is initiated at small anomalous zones and grows to instability with access to a continuous volume of strain energy the dimensions and temporal evolution of the growing anomaly can then be expected to relate to the size location and timing of the impending seismic event borehole log evidence indicates however that rock heterogeneity correlation lengths are unbounded and hence that the effective continuum approximation for rock must be applied with discretion an infinite correlation length indicates a statistical mechanical critical point system in which the correlation length is related to a singularity in a physical property in thermodynamic critical systems the singularity occurs at the critical system temperature tc 1 t tc in rock the singularity occurs at the critical percolation probability pc 1 p pc statistical physics descriptions of critical point spatial correlations are based on nearest neighbour inter actions at every scale length nearest neighbour interactions at one scale say that of large failure structures the loci of large earthquakes involve minimal coupling to structures at other scales in particular small scale failure structures the loci of small earthquakes the mechanics of nearest neighbour interactions plausibly form a fundamental constraint on the role of small scale failure or related nucleating activity as a prelude to large scale failure in light of 1 the evidence against rock being an effective medium notionally supporting localized precursory activity that reliably grows to large scale mechanical failure and 2 the history of failure to identify reliable precursors to major earthquakes the onus should now be on advocates of earthquake prediction schemes to evaluate their claims for precursory activity in terms of rock as a critical point system

a systematic compilation of earthquake precursors article a survey of published scientific literature was undertaken to identify and catalog observed earthquake pre cursors the earthquake precursors selected for analysis included electric and magnetic fields gas emissions groundwater level changes temperature changes surface deformations and seismicity for each of these precursors the published scientific literature was searched to document the statistics of each reported earth quake precursor spatial extent time duration amplitude signal noise ratio to analyze dependence of the observable for each precursor on earthquake magnitude and to explore proposed physical models to explain eachearthquakeprecursor somegeneralcharacteristics wereobservedfortheseprecursoryphenomena first the largest amplitude precursory anomalies tend to occur before the largest magnitude earthquakes also the number of precursory anomalies tends to increase the closer in time to the occurrence of the earthquake finally theprecursoryanomaliestendtooccurclosetotheeventualepicenterof theearthquake ingeneral the physical models indicate that all of the precursory phenomena are related to deformation that occurs near the fault prior to the main earthquake while the models provide plausible physical explanations for the pre cursors there are many free parameters in the models that are poorly resolved

holocene environmental changes in namibia inferred from pollen analysis of swamp and lake deposits spring deposits exposed during building operations in downtown windhoek and lake sediments retrieved from underneath 50 m of water in a sinkhole lake otjikoto contain pollen profiles which reflect environmental changes in namibia during the holocene at windhoek moist local conditions are reflected by pollen in the spring deposits which were radiocarbon dated to between ca 7000 and 6000 bp they remained relatively favourable until 5630 bp despite signs of drying weedy compositae lactucoideae or liguliflorae increased until the end of this record ca 2410 bp indicating local disturbance deposits from lake otjikoto were dated to the late holocene although an accurate chronology could not be estabiished for the sequence due to unexpected results with radiocarbon measurements pollen accumulation values and composition indicate relatively dry conditions after 3500 bp which were followed temporarily by a wetter climate during more recent times

reconstruction of environmental and climate changes at braamhoek wetland eastern escarpment south africa during the last 16 000 years with emphasis on the pleistocene holocene transition abstract a paleo environmental record covering the last 16 ka 16 000 cal yrs bp from the eastern areas of the summer rainfall region in south africa is presented this area is until now sparsely investigated due to the lack of well preserved natural archives for this study we used a peat section from a wetland situated close to the drakensberg escarpment where the high annual rainfall amounts supported a continuous peat accumulation since c 16 ka one peat core was analysed in terms of fossil pollen composition carbon and nitrogen content isotope composition 13c 15n and microscopic charcoal concentration the greatest degree of temporal resolution was achieved from the late pleistocene and early holocene section where proxy records indicate relatively dry conditions between ca 16 13 7 ka 12 8 10 5 ka 9 5 8 2 ka and wet conditions between c 13 7 12 8 ka and 10 5 9 5 ka a weak moisture signal is also evident at c 8 2 7 5 ka the late pleistocene to early holocene period was relatively cool while conditions became generally warmer after 11 8 ka the interpretation of the mid and late holocene sequence is limited due to a slow accumulation and low sample resolution but the available data suggest relatively dry conditions until c 1 5 ka followed by more humid conditions until c 0 5 ka we suggest that the millennial scale variability within the record can be attributed to shifts in the circulation systems dominating the region i e the latitudinal movements of the inter tropical convergence zone itcz and the dynamics of the mid latitude low pressure belts

an anomalous radon decrease in groundwater prior to an m6 0 earthquake a possible precursor a significant decrease in the radon concentration of artesian groundwater was observed at a well established observation site in northeast japan about two days before an m 6 0 earthquake occurred about 200 km from the site on the basis of a concurrent in situ minus 126 m temperature drop of the groundwater the authors infer that precursory changes in regional stress were locally amplified near this site and resulted in the temporary mixing of cooler radon poor groundwater into the normal artesian flow

modelling the mixing function to constrain coseismic hydrochemical effects an example from the french pyrenees groundwater coseismic transient anomalies are evidenced and characterized by modelling the mixing function f characteristic of the groundwater dynamics in the ogeu western french pyrenees seismic context investigations of water rock interactions at ogeu indicate that these mineral waters from sedimentary environments result from the mixing of deep waters with evaporitic signature with surficial karstic waters a 3 year hydrochemical monitoring of ogeu springwater evidences that using arbitrary thresholds constituted by the mean 1 or 2 as often performed in such studies is not a suitable approach to characterize transient anomalies instead we have used a mixing function f calculated with chemical elements which display a conservative behavior not controlled by the precipitation of a mineral phase f is processed with seismic energy release es and effective rainfalls r linear impulse responses of f to es and r have been calculated rapid responses 10 days to rainwater inputs are evidenced consisting in the recharge of the shallow karstic reservoir by fresh water complex impulse response of f to microseismic activity is also evidenced it consists in a 2 phase hydrologic signal with an inflow of saline water in the shallow reservoir with a response delay of 10 days followed by an inflow of karstic water with a response delay of 70 days the amount being higher than the saline inflow such a process probably results from changes in volumetric strain with subsequent microfracturation transient episodes allowing short inflow of deep salted water in the aquifer this study demonstrates that groundwater systems in such environments are unstable systems that are highly sensitive to both rainfall inputs and microseismic activity impulse responses calculation of f to es is shown to be a powerful tool to identify transient anomalies similar processing is suggested to be potentially efficient to detect precursors of earthquakes when long time series 5 years at least are available in areas with high seismicity

chronology and controls of donga gully formation in the upper blood river catchment kwazulu natal south africa evidence for a climatic driver of erosion dongas gullies and badland type terrain are found extensively across interior south africa but the controls on their formation remain contested establishing the timing of donga formation is essential for developing a clearer understanding of the relative importance of natural e g climatic and human e g overgrazing controls here we present optically stimulated luminescence osl ages for colluvial sediments exposed in the sidewalls of dongas and for tributary fan sediments deposited downslope of dongas in the upper blood river catchment eastern south africa the tributary fan ages enable the timing of donga formation to be established since fan sedimentation is a direct result of upslope donga erosion the osl ages indicate that net colluviation and intervening palaeosol formation occurred from prior to 22 ka until 1 6 ka from 0 89 ka to present there has been a shift to net erosion characterised by widespread donga formation and tributary fan sedimentation contemporary donga formation i

climatic conditions in southern africa since the last glacial maximum inferred from pollen analysis abstract a review of late quaternary palaeoclimatic data derived from several pollen sequences between ca 22 and 34 s in southern africa shows a degree of similarity in temperature and moisture variations between the various site pollen data from sites such as wonderkrater and rietvlei transvaal tate vondo venda elim orange free state equus cave southern kalahari and boomplaas cape province suggest relative dryness during the last glacial maximum wet conditions during the late glacial and dry conditions during the early holocene ca 8000 yr b p followed by progressively moister conditions peaking soon after the development of a temperature optimum ca 6500 yr b p problems with radiocarbon dating of polleniferous spring deposits however prevent precise correlations of especially late pleistocene sequences different seasonal patterns in the late glacial and early holocene may explain palaeobotanical data and are partly compatible with simulations of past climates of kutzbach and guetter 1986

vegetation history inferred from pollen in late quaternary faecal deposits hyraceum in the cape winter rain region and its bearing on past climates in south africa abstract pollen analysis shed light on vegetation community structure over the last 23 000 year in the western cape the pollen from dated hyrax faecal accumulations hyraceum relates to the evolution of climate and contributes to proxy records in southern africa principal components analyses of the pollen data and 13c values of the hyrax dung samples show millennial and shorter scale temperature moisture and seasonality variations in the winter rain region the moisture availability at times do not parallel that in previously studied proxy records in the summer rain region showing an asynchronous moist event in the early holocene and drier conditions in the middle holocene anomalies in climate between the two regions may depend on the degree of northward or southward shifting of winter and summer rain circulation systems scenarios with winter rain or cool growing seasons mostly typify the dung sequence but do not exclude the possibility of southward displacement of the westerly belt under precessional strength with slight summer rain increases during the last glacial maximum limited southward displacement is also possible during the mid holocene

earthquake forerunners in a selected area of northern italy recent developments in automatic geochemical monitoring abstract this article describes the monitoring of certain mud volcanoes in the northern apennines of italy this monitoring was carried out from a geochemical point of view and its aim was to verify the seismic precursory nature of the mud volcano fluids the operational strategy began by determining the regional character of the main physical and chemical precursors and a multidisciplinary approach to the historical research was used to achieve this the utility of such an approach in monitoring strategy has been confirmed a series of experiments was carried out to identify the physical model the main geochemical characteristics and the origin of the seismic precursory phenomena with particular reference to radon 222 the technological apparatus necessary for a reliable automatic continuous monitoring system of the geochemical parameters of mud volcanoes were then extensively tried out the first results of this monitoring system refer to dec 1988 jan 1989 in this period there were some seismic events which were preceded by certain phenomena we can call precursory an interpretative model has been created from all the information collected so that similar situations can be better understood from a physical and chemical point of view

earthquake prediction a political problem earthquake prediction is an area of research of great scientific and public fascination the reason for this is not only that earthquakes can cause extremely large numbers of fatalities in a short time but also because earthquakes can have a large social and economic impact on society earthquake prediction in the sense of making deterministic predictions about the place time and magnitude of earthquakes may very well be fundamentally impossible however based on a variety of data earth scientists can make statements about the probability that earthquakes with a certain size will occur in a certain region over a specified time period in this context one speaks of earthquake forecasting a number of methods to achieve this are presented however it is not obvious how society should respond to these forecasts it is shown that there is a fundamental dilemma for decision makers that statements of scientists concerning earthquake occurrence either contain very specific information but are very uncertain or contain very general information but are very certain earthquake hazard can to a large extent be reduced by formulating and enforcing appropriate building codes however given the fact that the majority of the population that is threatened by earthquakes is living in the third world it is clear that this cannot easily be realized for these reasons earthquake prediction is not only a scientific problem it also has a complex political dimension

tectonic leakage of fault bounded aquifers subject to non isothermal recharge a mechanism generating thermal precursors to seismic events abstract the thermal consequences of flow transients generated by deformation induced leakage at fault zones intersecting confined aquifers have been examined using a simple analytical model the recharge of the aquifer is assumed to take place by vertical infiltration through the confining layers the energy equation relevant in this case has been derived by evaluating enthalpy fluxes associated with lateral and vertical components of fluid flows as well as that due to volume changes in the permeable layer generated by deformation induced alterations in the hydraulic head results of numerical simulations indicate that thermal transients arise during the stress build up period when the infiltrating fluids mix with those in the aquifer but relatively rapid return to equilibrium conditions occur as soon as the leakage is cut off the model is thus capable of reproducing the characteristic features of thermal precursors found in observational records according to model results the growth of thermal perturbation as well as the time for attaining steady state conditions is proportional to the recharge rate the magnitude of the perturbation is related to the thermal gradients in the confining layers but permeability contrast between the confining layer and the aquifer also plays a significant role the model results also indicate that precursory signals are likely to be significant only in areas close to the fault plane where tectonic leakage has a direct influence on the hydraulic head of the aquifer if the fault plane is sensitive to deformation the tectonic leakage rate may undergo substantial changes in response to changing stress patterns and this in turn may easily lead to abrupt and substantial changes in the local thermal regime some of the transient thermal anomalies observed in records of temperatures in boreholes in tectonically active areas have characteristics similar to those predicted by the deformation induced leakage model examples are presented illustrating model fits to thermal transients identified as precursors to seismic events in firjusa turkmenistan didiweli georgia and izu peninsula japan the possibility of obtaining complementary information on processes responsible for fluid flow during pre seismic periods is pointed out it appears that the occurrence of thermal anomalies associated with small scale tectonic deformation may not be uncommon its detection depends on availability of suitable boreholes and of the facilities for monitoring of temperatures using high precision sensors over periods comparable to local recurrence periods of earthquakes

reconciliation of vegetation and climatic interpretations of pollen profiles and other regional records from the last 60 thousand years in the savanna biome of southern africa abstract long environmental proxy records are very scarce in semi dry continental areas and often those available present conflicting interpretations however more in depth investigation of apparent contradictions can address these problems for example comparison of the upper parts of pollen and sediment sequences from the tswaing crater and wonderkrater spring south africa and isotopes in a speleothem at lobatse cave botswana from the savanna biome establishes a basis for understanding of long term regional environmental processes in central southern africa over the last 60 ka the different proxies for the vegetation can hypothetically be reconciled on condition that the chronologies on which they are based and environmental controls are firm we discuss the ratio of woody elements under storey herb cover and the vegetation s general c4 c3 status in the central savanna region in relation to seasonal rainfall and temperature variations and long term climate forcing