Laboratory of Exploration Geophysics West Building 2, office 431. Department of Earth Resources Engineering Faculty of Engineering, Kyushu University 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan.
Hakim SAIBI Associate Professor Laboratory of Exploration Geophysics International Education Center of Kyushu University, Japan Email: saibi.hakim@gmail.com
Research interests: Exploration Geophysics (measurements, analysis, interpretation, modeling, inversion), microgravity (relative and absolute, applied on geothermal and volcanological fields), Reservoir Engineering (3D geothermal reservoir simulation), GIS, Hydrochemistry and Hydrogeology.
PROFESSIONAL EXPERIENCE
Faculty of Engineering, Kyushu University, JAPAN (January 2010 - Actual): Teaching Undergraduate Students: Heat and Waves. Teaching Graduate Students (Master & PhD): Geophysics.
INNOVATION TRAINING PROGRAM CENTER, KYUSHU UNIVERSITY – FUKUOKA, JAPAN 7/2009–12/2009 (3 months Internship at West JEC company, Fukuoka) Post-Doctoral Fellow - Doctor with Business Expertise-
FACULTY OF ENGINEERING, KYUSHU UNIVERSITY – FUKUOKA, JAPAN 2007–2009 JSPS (Japan Society for the Promotion of Science) Post-Doctoral Researcher
FACULTY OF SCIENCES, UNIVERSITY OF ALGIERS – ALGIERS, ALGERIA 2002-2003 Lecturer in Geosciences
EDUCATION Bachelor of Science in Earth Sciences, 2000, UNIVERSITY OF SCIENCE AND TECHNOLOGY, ALGERIA Masters of Science in Earth Sciences, 2003, UNIVERSITY OF SCIENCE AND TECHNOLOGY, ALGERIA Ph.D. of Engineering in Earth Resources Engineering, 2007, Kyushu UNIVERSITY, JAPAN
AWARD
European Post-doctoral Fellowship 2009
JSPS Post Doctoral Fellowship for Foreign Researchers Program 2007 (Japan Society for the Promotion of Science) at Kyushu University, Faculty of Engineering.
Best Student Paper Award 2005 from EAGE 2005 (European Association of Geoscientists & Engineers) For presenting at the 2nd North African/Mediterranean Petroleum & Geosciences Conference and Exhibition.
Japanese Govt. Scholarship for postgraduate studies (Monbusho fellowship) 2003 Kyushu University, Japan
Excellent distinction for the graduation as an Engineer in Geology 2000 University of Science and Technology Houari Boumedienne, Algiers, Algeria.
Invited Talk at Low Carbon Earth Summit (19-26 October 2011) in Dalian, China Session: Geophysics and Geothermal Energy
Chairman: Session Coastal Engineering International Symposium on Earth Science and Technology (7-8 December 2010) in Fukuoka, Japan Chairman: Mineral Resources in Asia International Symposium on Earth Science and Technology (6-7 December 2011) in Fukuoka, Japan
Peer Reviewer Geophysical Research Letters Arabian Journal of Geosciences, Springer Environmental Progress & Sustainable Energy, Wiley InterScience
Professional membership American Geophysical Union (AGU) since 2006 European Association of Geoscientists & Engineers (EAGE) since 2004 Society of Exploration Geophysicists (Associate Member) Geothermal Research Society of Japan (GRSJ) since 2004
Abstract: The Aluto-Langano geothermal field is located in the central southern portion of Ethiopia within the Ethiopian Rift Valley. The gravity of the area was surveyed in an attempt to delineate the subsurface structure and to better understand the relationship between the geothermal systems and the subsurface structure. The gravity data were analyzed using integrated gradient interpretation techniques, such as the Horizontal Gradient (HG), Source Edge Detection (SED), and Euler Deconvolution (ED) methods. These techniques detected many faults that were compared with the mapped faults in the surface geology. The results of the present study will lead to an improved understanding of the geothermal system in the study area and aid future geothermal exploration of the area.
Abstract: The Gulf of Suez region is one of the most interesting geothermal areas in Egypt because of the high temperatures of its springs. The eastern and western shores of the Gulf of Suez are characterized by superficial thermal manifestations including a cluster of hot springs with varied temperatures. Variations of deuterium and oxygen-18 concentrations in thermal waters have been used to aid in describing the source of recharge in the Gulf of Suez hot springs. Isotope and geochemical data for the Gulf of Suez thermal waters suggest that recharge to the hot springs may not be entirely from the Gulf of Suez water, but possibly from the meteoric water that comes from areas of higher altitude surrounding the hot springs.
Abstract: The tectonic position of Egypt in the northeastern corner of the African continent sug-gests that it may possess significant geothermal resources, especially along its eastern margin. The eastern margin is characterized by the existence of what has been interpreted as a median spreading center in the Red Sea and the Gulf of Suez. Gravity and magneto-telluric surveys were conducted in the area of the Hammam Faraun hot spring, which represents the most promising area of geothermal development in Egypt. The results from the analyses and interpretations of these data were used to construct a conceptual model of the hydrothermal system in the Hammam Faraun hot spring. The final product of the modeling process was a computer model that included all simplifications and assumptions made in the conceptual model. This study was assisted by an assessment of the potential for geothermal resources to be used for conventional electric power production in the Hammam Faraun region.
Abstract: In this study, the physicochemical parameters (Conductivity, pH, Clâ, HCO3â, PO43â, SO42â, NO3â, NO2â, Fâ, TH, Ca2+, K+, Mg2+, Na+, and DS) were determined for 41 samples collected from fourteen places in Algeria. The temperature of the thermal water samples at collection sites varied from 26°C to 86°C. pH values varied from 6.5 to 8.5 (i.e., from slightly acidic to moderately alkaline); 90.24% of the samples exhibited relatively high salinity (DSâ=â550â5,500 mg Lâ1). Total hardness measurements indicated these waters to be moderately hard. Forty-six percent of the samples are NaâCl in character. The ratios Na+/Ca2+, Na+/Mg2+, and (Na+ + K+)/(Ca2+ + Mg2+) were high in 90.24% of the samples. This indicates the ion exchange process is important, which indicates that most of the Algerian thermal waters had developed over a long period at a depth sufficient to react with the rock. Statistical analyses of the physicochemical data gave positive correlation values, thereby enabling good interpretation of the results and revealing the composition of ions present in the thermal waters, as well as some information about their origin. The therapeutic properties associated with thermal waters encourage people at spas to drink the water they bathe in. Therefore, we examined the drinkability of these thermal waters. World Health Organization (WHO 1993) standards were used to evaluate the thermal water quality for drinking. With respect to hardness, the samples were classified as moderately hard (58.54% of the samples), very hard (36.58% of the samples), and soft (4.88% of the samples). The drinkability study shows that only 16 samples of the investigated waters were drinkable and thus could be consumed without special precaution.
Abstract: Magnetotelluric (MT) soundings and gravity methods were employed to study the deep freshwater aquifer in the area north of Abo Zenema city on the eastern side of the Gulf of Suez, Egypt. Seven MT sites and 48 gravity stations were surveyed along northeast-southwest profiles as close as possible to a line perpendicular to the coast of the Gulf of Suez. The MT survey was conducted using high and low frequencies to investigate shal-low and deep areas, respectively. One-dimensional inversion was conducted using a heu-ristic inversion scheme of the Bostick algorithm. The MT data were also inverted with a 2-D smooth model inversion routine using the nonlinear conjugate gradient method to infer variation in vertical and lateral resistivity inside the Earth. A 100-Ohm-m homoge-neous half-space initial model was used to invert the TE mode data only. Then, the in-verted model obtained from the TE mode data was used as an initial model for inversion of the TM mode data. The inverted model thus obtained from the TM mode data inver-sion was used as an initial model for the inversion of the joint TE and TM responses. Two-dimensional (2-D) forward modeling of the gravity data was conducted using the 2-D polygon method of Talwaniâs algorithm for an arbitrarily shaped body and was based on the subsurface information from the MT survey and the available information about the geological structure of the study area. This method enabled us to obtain the basement structure of the coastal aquifer in the study area. The results from the analysis and the in-terpretation of MT and gravity data were used to detect and delineate the groundwater coastal aquifer in the study area.
Abstract: This study presents the physicoâchemical and the bacteriological characteristics of 26 springwaters from nine regions (western and Saharan regions) of Algeria: Mostaganem, Mascara, Ain Temouchent, Tlemcen, Saïda, Chlef, Adrar, Bechar and Ghardaia. In total, 26 groundwater samples have been analyzed for major physicoâchemical elements and metals. The results show that the water samples exhibit pH values that range between 7 and 8.1, salinities that range between 216 and 1,082 mg/L, and nitrate concentrations that range between 0.25 and 47.5 mg/L. The samples are mainly of the Ca-Na-HCO3 type. The chemistry of the springwaters results from their contact with carbonate rocks. All the trace metal concentrations are within the admissible standard ranges, except those of Zn and Mn; some springwaters present slightly high values of these metals. The bacteriological analysis of the 26 samples analyzed showed that five samples (nos. 1, 8, 12, 13, and 18) are contaminated. We conclude that the groundwater samples may be safely used for drinking, domestic, agricultural, and industrial purposes, with the exception of sample nos. 1, 8, 12, 13, and 18. Herein, we employed descriptive statistics, correlation matrices, and principal component analyses to understand the hydrogeochemistry of the springwater in the western and Saharan parts of Algeria.
Abstract: We report on results from post-eruptive time-lapse gravity investigations performed between 1999 and 2004 at Unzen volcanic complex, Shimabara Peninsula, Kyushu Island, southwest Japan. One of the most active volcanoes in Japan, Unzen saw its most recent eruption between 1990 and 1995. Here we demonstrate that annual residual gravity variations reflect subsurface mass changes most likely coupled to changes in shallow aquifer levels on the order of several meters. We find a positive correlation between rainfall and gravity data with a 3 to 4 month lag time. We interpret this link as a delayed aquifer response to local rainfall and show that high permeability rocks of the Unzen complex are indicative for low aquifer storativity, which in turn results in substantial water table fluctuations upon deviation from average rainfall budgets. While aquifer dynamics may represent a first order explanation to the observed gravity data, hydrothermal fluid circulation in the feeder system of the recent eruptive episode is also likely to contribute to the gravity signals by deteriorating the signal-to-noise ratio compared to hydrothermally quieter volcanoes. This study shows that shallow hydrological processes may dominate temporal changes in the gravity field after dome-building eruptions identifying a clear need for a better understanding of the interaction between magmatic and hydrological systems at arc volcanoes.
Abstract: Thermal waters from Quaternary volcanic rocks (predominantly andesites) discharge along faults in the Obama geothermal field of southwestern Japan. The chemistry of more than 100 thermal and ground water samples collected between 1936 and 2005 indicate that the NaâCl hot spring waters are a mixture of âandesiticâ magmatic, sea and meteoric waters. Mixing models and silica and cation geothermometry were used to estimate the SiO2 and Cl composition and the temperature (not, vert, similar200 °C) of the reservoir fluids deep in the geothermal system. The isotopic data (18O and D) are consistent with a mixed origin interpretation of the waters feeding the Obama hot springs, i.e. a large proportion of meteoric and sea waters, and a small magmatic component. Temperatures and chemical concentrations of the thermal waters were affected by the 1944â1959 salt production operations, but have recovered after closure of the salt factories; now they are similar to their pre-1940 values. In the future, the Obama geothermal field may be suitable for electric power generation, although heat and fluid extraction will require careful management to prevent or minimize reservoir cooling.
Abstract: Mostaganem City, located in the northwestern part of Algeria, has grown and has been urbanized rapidly. The city and surrounding areas depend heavily on groundwater as a resource for drinking water, as well as domestic, industrial, and agricultural uses. Understanding the groundwater chemistry provides insight into the interactions of water with the environment and contributes to better resource management. In total, 12 groundwater samples from wells in Mostaganem City have been analyzed for major physicalâchemical elements and metals. The results show that the waters have pH values ranging between 7.1 and 8.1, salinity between 226 and 1,073 mg/L, and nitrate concentrations between 15 and 47.7 mg/L. The high concentration of nitrates is explained by the utilization of chemical fertilizers in agriculture. Almost all samples are of type NaâSO4 and NaâHCO3, and the trace metal concentrations are within the admissible standard ranges. We conclude that the groundwater in Mostaganem may safely be used for drinking, domestic, agricultural, and industrial purposes.
Abstract: Ungaran Volcano is located in the province of Central Java, Indonesia, and is a Quaternary volcano that consists of older and younger volcanoes. The older Ungaran volcano formed over 500,000 years ago, and the younger volcano was active until 300,000 years ago. The younger volcano seems to have been constructed inside a caldera formed by the older Ungaran activity. In this study, gravity data was used in an attempt to determine the exact location of the younger and older Ungaran volcanoes, and to investigate the relationship between fault structure and geothermal manifestations.
A positive Bouguer anomaly was observed over the volcanic body. From detailed analysis of the gravity data, high anomalies were located over the northern part of the summit that correlate with the older Ungaran volcano. Various interpretation methods, such as horizontal gradient analysis, spectral analysis, and 2-D forward modeling, were applied to the gravity data. The younger Quaternary volcanic rocks, which consist of hornblende-augite-andesite (andesite lava) of the Gajahmungkur volcanics, have an average density of 2,390 ± 120 kg/m³, while the older Quaternary volcanic rocks, consisting of augite-olivine basalt flows (basaltic lava) from the Kaligesik formation, have an average density of 2,640 ± 100 kg/m³. The structural setting of the Ungaran volcano has characterized by circular structure where most geothermal manifestations are located. The result of gravity analysis shows that Ungaran volcano seems to have occurred in tectonic depression, and prominent caldera depression has not formed within Ungaran volcano without surficial caldera rim. The horizontal gradient analysis indicates that geothermal features at Ungaran volcano are structurally controlled and are located within the younger volcano.
Abstract: Phreatic aquifers present many serious problems for local public authorities, and they have done so especially for the water resources managers in Oued-Souf, Algeria, since 1980. Recently, a perturbation in piezometric level was observed in Oued-Souf. The spatial distribution of piezometric level data was analyzed by applying geostatistical methods, which provide an indication of the uncertainty of the estimation using the computer software VARIOWIN 2.2. In this paper, the evolution of the piezometric level by referring to other research campaigns was studied. Campaigns were conducted from March 1993 to April 2002. In the beginning, elementary statistics has been carried out to understand the statistical distribution and performed an analysis of variance so that two campaigns could be chosen for comparison. Geostatistics for modeling and cartography were applied. The results show that piezometric levels admit power model that the direction of groundwater flow is from south to north and that, due to the return of irrigation water (there is no drainage system), water levels increase in places like Foulia (1.35 m), northwest of Oued-Souf (1.43 m), Kouinine (4.58 m), and Ouzitene (3.01 m). The water levels also decrease in places like Guemar, Dmitha, Rhamra, and Djeldida, from between â2 and â6 m, due to excessive pumping of groundwater.
Abstract: The geothermal resources in Algeria are of low-enthalpy type. Most of these geothermal resources are located in the northeastern of the country. There are more than 240 thermal springs in Algeria. Three geothermal zones have been delineated according to some geological and thermal considerations: (1) The Tlemcenian dolomites in the northwestern part of Algeria, (2) carbonate formations in the northeastern part of Algeria and (3) the sandstone Albian reservoir in the Sahara (south of Algeria). The northeastern part of Algeria is geothermally very interesting. Two conceptual geothermal models are presented, concerning the northern and southern part of Algeria. Application of gas geothermometry to northeastern Algerian gases suggests that the reservoir temperature is around 198 °C. The quartz geothermometer when applied to thermal springs gave reservoir temperature estimates of about 120 °C. The thermal waters are currently used in balneology and in a few experimental direct uses (greenhouses and space heating). The total heat discharge from the main springs and existing wells is approximately 642 MW. The total installed capacity from producing wells and thermal springs is around 900 MW.
Abstract: The present work deals with the integration of remote-sensing, surface-geology and gravity-survey data to improve the structural knowledge of the Tarhunah area, northwest Libya. Geological information and remote-sensing data provided information about the surface structure. A gravity survey was conducted to decipher the subsurface structure. The results revealed that a basin having a width of 39 to 48 km trends NE. A two-dimensional (2-D) schematic model shows that the basin gradually deepens toward the southwest. Faults determined from a horizontal gradient, tilt derivative, and Euler deconvolution show a depth range of 2.5 to 7.5 km. The integration and interpretation of the results indicate that volcanic activity was related to the tectonic activity of an anticlinal structure called the Jabal Uplift.
Abstract: This study utilized the GIS technique and the DRASTIC method to assess the vulnerability of groundwater resources to contamination in the Mostaganem plateau, northwestern Algeria. The DRASTIC groundwater vulnerability map shows regional groundwater areas that are sensitive to contamination on the basis of hydrogeologic conditions. Seven hydrogeologic factors were used for the vulnerability assessment. There are depth to water table, net recharge, aquifer media, soil media, topography, impact of the vadose zone, and aquifer hydraulic conductivity. The vulnerability maps were constructed using MAPINFO software. The areas of highest contamination vulnerability are Mostaganem city and Mazagran city. The areas of lowest contamination vulnerability are located in the northern part of the study area. A risk of pollution map is developed from the combination of the vulnerability map with the sources of pollution map.
Abstract: In this study, we successfully integrated geological data, potential field data, and remote sensing data with the aim of investigating and improving our knowledge of the structural setting of the Eljufra area, northwestern Libya. SPOT-5 panchromatic band and digital elevation models (DEM) were used to construct surface shaded maps, and gravity and aeromagnetic surveys were used to provide information on subsurface structures and the nature of intrusive bodies. The results revealed that the prevailing trend of lineaments is NNW-SSE and NNE-SSW. A Bouguer anomaly map revealed that horst and graben blocks occur inside the large graben. An analytic signal method was applied to the aeromagnetic data to estimate locations and the minimum depths to the contact. A comparison of gravity and magnetic data provided information on hydrothermally altered basalt and sediment density. An anticlinal structure was detected in the western part of the study area. The effects of faults on basalt rocks indicated geological time for volcanic activity.
Abstract: The Fukuoka area is located in the southwestern part of Japan. The Yokote-Ijiri area, located in the southern part of Fukuoka city, has several low-temperature geothermal systems, including eleven hot springs. From 1996 to 2008, the Fukuoka area was investigated by gravity survey, using Scintrex CG-3 and CG-3M gravimeters, in an attempt to delineate its subsurface structure. The surveys were intended to improve the understanding of the relation between the geothermal systems and the subsurface structure as well as to locate the active faults in the surveyed area, which are responsible for generating large earthquakes. The gravity data were analyzed using integrated gradient interpretation techniques, such as the Horizontal Gradient (HG), Tilt Derivative (TDR), and Euler deconvolution methods. With these techniques, many faults were detected, including the famous Kego fault, which is an active fault in Fukuoka city. A 2-D gravity model was constructed to show the relationship between the faults and the geothermal systems. The results of the present study will hopefully lead to an understanding of the relationships between the interpreted faults and the location of the low-temperature geothermal systems and possibly aid in future geothermal exploration of the area.
Abstract: The Obama geothermal field is located on the western part of Kyushu Island, Japan. This area has importance due to its high geothermal content which attracts sporadic researchers for study. In 2003 and 2004, Obama was covered by gravity surveys to monitor and evaluate the geothermal field. In this paper, the surveyed gravity data will be used in order to delineate and model the subsurface structure of the study area. Gradient methods such as analytic signal and vertical derivatives were applied to the gravity data. The available borehole data and the results of the gradient interpretation techniques were used to model the Obama geothermal field. In general, the obtained results show that the gradient interpretation techniques are useful to obtain geologic information from gravity data.
Abstract: There are more than 240 thermal springs in Algeria. The geothermal energy in Algeria is generally of a low enthalpy type. The total heat discharge from the main springs and existing wells is approximately 642 Mwt. Three geothermal zones have been delineated according to some geological and thermal considerations: 1) The Tlemcenian dolomites in the northwestern part of Algeria, 2) carbonate formations in the northeastern part of Algeria and 3) the sandstone Albian reservoir in the Sahara (south of Algeria). The northeastern part of Algeria is geothermally very interesting. Application of gas geothermometery to northeastern Algerian gases suggests that the reservoir temperature is around 198°C. Two conceptual geothermal models are presented, concerning the northern and southern part of Algeria. The principal utilizations of the hot water are balneology and space and greenhouse heating. Eight hot springs are used as public thermal resorts for medical purposes.
Abstract: Obama geothermal area is located on the western side of Kyushu Island, southwestern Japan. This area is characterized by high potential geothermal resources that attract most of researchers to study the subsurface structure of the area. Euler deconvolution is applied to newly acquired gravity data to image the subsurface structures thereby aiding the geothermal exploration. The results were compared with the available geologic and geothermal information in order to get a relationship between structures and geothermal resources. These analyses indicate that the dominant subsurface faults trend E-W, but N-S trending faults also exist. The dominant orientation of these faults provides a geothermal relation between subsurface structures and geothermal resources in the Obama geothermal field.
Abstract: The present work deals with the integration of remote sensing data with surface geology and gravity survey to improve the structural knowledge of the Tarhunah area, northwest Libya. Geological information and remote sensing data provided information about the surface structure. The gravity survey was conducted to explore the subsurface structure. The results revealed a basin trends in the NE direction with width varying from 39 to 48 km. A 2D schematic model shown the basin is gradually deeper toward the southwest direction. Faults extracted from horizontal gradient, tilt derivative, and Euler Deconvolution shown a depth ranges from 2.5-7.5 km. The integration and interpretation of the results indicates that the study area was affected by three main movements. And the volcanic activity was related to the tectonic activity of Jabal Uplift.
Abstract: The Obama geothermal field is located in the western side of Kyushu Island, southwestern Japan and exactly on the western foot of Unzen volcano and in front of Chijiwa bay. This area is characterized by high potential geothermal resources. The Obama spa is historically noted for the abundance and high temperature of its spring waters. The Obama geothermal field is a dynamic system, and its coastal location allows the incorporation of seawater into the underground circulating waters. It was suggested that Obama geothermal field is originated from magmatic emanations derived from a magmatic reservoir, at about 15 km depth beneath Chijiwa bay.
For the detailed understanding of the Obama geothermal field, a numerical simulation technique has been carried out at the Obama geothermal field after combining gravity and hydrochemical results.
First, we studied the structure of Obama geothermal field using integrated gravity interpretation techniques such as: 3-D inversion, analytic signal, Euler deconvolution, transformations and 2-D modeling of the gravity data. These analyses indicate that the dominant subsurface faults trend E-W, but N-S trending faults also exist. The substratum of the Obama geothermal field is characterized by many grabens and horsts separated by normal faults. Also, a micro-gravity monitoring was conducted at Obama geothermal field from 2003 to 2004 and showed an increase by about 95 ïgal, which is attributed to groundwater level change and increasing of reservoir pressure. The calculated anomalous mass is 15 Mt. The recovery of reservoir pressure is caused by the recent limitation in withdrawal of hot water.
Secondly, a hydrogeochemical study of Obama hot spring waters was carried out. Some chemical/isotope geothermometers, fluid/mineral equilibrium modeling and mixing models were analyzed. All hot spring waters are of Na-Cl in type. The reservoir temperature is estimated to be 210oC. The Obama geothermal reservoir is recharged by deep-chloride waters and secondarily by meteoric/surface and seawater, with a sea water mixing ratio of 24%. In general, the Obama geothermal field is in recovering process with the recovering of the water quality, increasing in the number of boiling well, rising in the water temperature, and decreasing in the salinity.
Finally, a comprehensive hydrothermal model of the Obama geothermal field was constructed. Building the Obama geothermal field, two heat sources were necessary. The first one (Source I) is located in the eastern part of Obama geothermal field, associated to the Unzen fumarolic field. The second one (Source II) is located beneath the Obama geothermal field. The physical properties of the Source I and the Source II are enthalpy of 3200 kJ/kg, 400 kJ/kg and a mass flow of 300 kg/s, 30 kg/s, respectively. The characteristics of the first source agree with the previous geochemical studies. The second source seems to be cooled by the infiltrating low temperature waters. An estimation of heat supply was calculated. 1000 MWt was supplied from the first source and just 12 MWt from the second source. We must note that the major part of the heat supplied from the first source was discharged into the sea. From the above results, the Obama geothermal field can be used much more for various kinds of geothermal energy utilization.
