ABSTRACT

SEISMO – IONOSPHERIC INDUCED PERTURBATIONS PRIOR TO THE SEPTEMBER 28, 2007 M7.5 NORTHERN MARIANA U.S.A. GEOQUAKE FROM GPS, TEC AND DEMETER DATA

Journal: Malaysian Journal of Geosciences (MJG)
Author: Jewel E. Thomas

This is an open access article distributed under the Creative Commons Attribution License CC BY 4.0, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited

DOI: 10.26480/mjg.01.2020.38.42

Data from DEMETER (IAP and ISL sensors) and GPS (TEC), were used to decipher variations of electron density, electron temperature and ion density within the seismogenic zone of a seismic event that occurred on September 28, 2007 at Northern Mariana U.S.A, through statistical analysis. The study revealed both pre and post ionospheric perturbations from both sets of data. The observed anomalous variations were screened for false alarm using the geomagnetic indices of kp and Dst. It was observed that the abnormal TEC on -10, – 7, -3 and -2 days occurred under quiet geomagnetic conditions while all pre-seismic (-15, -10, – 9 -7 days) ionospheric variations from the DEMETER data were also obtained during quiet geomagnetic conditions suggesting them to be seismo-ionospheric induced perturbations. Interestingly, the perturbations on -10 and -7 days were simultaneously observed from both GPS and DEMETER datasets under quiet geomagnetic ionospheric conditions offering a strong pointer to the impending geo-quake.

ABSTRACT

Flood mitigation measures using intuitionistic fuzzy dematel method

Journal: Malaysian Journal of Geosciences (MJG)

Author: Norzanah Abd Rahman, Zamali Tarmudi, Munirah Rossdy, Fatihah Anas Muhiddin

This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited

DOI: 10.26480/mjg.02.2017.01.05

Flood is a natural disaster induced by climate change that resulted in the losses of lives, damages to property, and disrupts the daily activities of local community. Thus, the flood mitigation measures are developed to reduce the impact of flood in our country. The aim of this paper is; to propose IF-DEMATEL method and deal with the uncertainty of input data set of flood mitigation measures, and to validate it using sensitivity analysis. Here, this method is used for flood mitigation measures comprise drainage improvements, barriers, wet flood proofing, dry flood proofing, elevation, relocation, and acquisition. A numerical example from the flood control project selection proposed by a researcher which was adopted to show the applicability of the proposed method. The result shows that the flood mitigation measures are placed based on their priority. Although the rank of flood mitigation measures is sensitive to changes based on the weight of criteria but the best measures is remaining unchanged.

ABSTRACT

Estimation of peak ground acceleration of ranau based on recent eartqhuake databases

Journal: Malaysian Journal of Geosciences (MJG)
Author: Noor Sheena Herayani Binti Harith, Azlan Adnan

This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited

DOI: 10.26480/mjg.02.2017.06.09

The occurrence of earthquake with magnitude MW 6.0 in Ranau recently has triggered many questions regarding their nature of recurrence, characteristics in size and mechanism in and its surrounding region. In recent years, Sabah has witnessed an increase in low to moderate seismic activities due to the causative ground structures which reflected in their seismic productivities. Over the past years between 1900 until recently, magnitudes ranging from MW 2.9 to 6.0 were known to have occurred. While large magnitude earthquakes are fortunately rare, in the history of earthquakes, the region already experienced devastating earthquake including a magnitude of MW 5.8 on 26th July 1976 centred in Lahad Datu. The observation on earthquake catalogue spanning from 1900 to 2014 has been obtained from various earthquake data centers, Ranau previously recorded an earthquake with magnitude MW 5.1, the repeat over intervals of sudden large earthquake is considered to have much shorter recurrence intervals. This paper discusses the procedure for evaluating the probabilistic seismic hazard analysis (PSHA) whereas the peak ground acceleration (PGA) on bedrock of Ranau area for 10% and 2% probability of exceedance is taken into account. By analysing the correlation between the tectonic features and the available data on past seismicity, the estimation of PGA is based on smoothed-gridded seismicity with a subjectively chosen correlation distance of 50 km. The PGA estimation values for Ranau are approximately in the range of 80 to 140 cm/s2 that will be exceeded 10% probability of exceedance and 140 to 250 cm/s2 for 2% probability of exceedance.

ABSTRACT

Research on data management model of national defense mobilization potential based on geo spatial framework

Journal: Malaysian Journal of Geosciences (MJG)
Author: LI Guoming，CHEN Yanmin，YING Guowei，WU Xiaoping

This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited

DOI: 10.26480/mjg.02.2017.10.12

At present, the national defense mobilization potential data is mainly unstructured data composed of text, images, report forms, lacking space attribute and location information. Therefore, a large study of national defense mobilization potential database has focused on data collection, reporting and information system construction, etc. To solve national defense mobilization potential data application problems in the construction of informatization, taking advantage of the characteristics of geographical spatial framework, this paper discusses national defense mobilization potential data management model based on geographical spatial framework.

ABSTRACT

Landslide susceptibility analysis lsa using weighted overlay method wom along the genting sempah to bentong highway pahang

Journal: Malaysian Journal of Geosciences (MJG)
Author: Rodeano Roslee, Alvyn Clancey Mickey, Norbert Simon, Mohd. Norazman Norhisham

This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited

DOI: 10.26480/mjg.02.2017.13.19

This study focused on the Landslide Susceptibility Analysis (LSA) of the Karak highway, which link the Genting Sempah to Bentong area, Pahang. The physical relief of the study area is largely flat to undulating and moderately rough to steep mostly. The aims of this study are to identify the landslide prone area and to produce the Landslide Susceptibility Level (LSL) map using Weighted Overlay Method (WOM) integrated with Geographic Information System (GIS) and remote sensing techniques. Landslide locations were identified in the study area from imagery and aerial photograph interpretations followed by field work observation. The topographic, geologic data and satellite images were collected, processed and constructed into a spatial database using image processing. The factors that influence landslide occurrences such as slope gradient, slope aspect, topographic curvature and distance from drainage were retrieved from the topographic database. Geomorphology, lithology and geological structure were generated from the geologic database; whereas land use and soil types from SPOT satellite data image. Several areas are considered as susceptible, such as areas of Ladang Fook Who, Kg. Temiang, Ladang Ng Chin Siu, Kemajuan Tanah Genting Pandak, Kg. Lentang, Kg. Baharu Bt. Tinggi and Ladang Pandak. To avoid or minimize the landslide occurrences, development planning has to consider the hazard and environmental management program. This engineering geological study may play a vital role in Landslide Risk Management (LRM) to ensure the public safety.

ABSTRACT

The crust and uppermost mantle s-wave velocity structure beneath japan islands revealed by joint analysis of p-and s-wave receiver functions

Journal: Malaysian Journal of Geosciences (MJG)
Author: Jun Wang, Hongtai xu

This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited

DOI: 10.26480/mjg.02.2017.20.23

We have studied the crust and uppermost mantle S-wave velocity structure beneath Japan Islands by using the teleseismic waveform data above Mw 6.0 recorded from January 2006 to February 2017 by 15 Hi-Net stations and the joint inversion technique of P- and S-wave receiver functions based on the Bayes theory. The results show that, beneath Japan Islands, the crust appear the characteristic of thinner in the south and east, and thicker in the north and west. The thinnest and thickest crust in the study region locate at station JSD (26km) and JGF(44km), respectively. The horizontal distribution of S-wave velocity in the study region are relatively complicated within upper and middle crust depth, while from the lower crust to the uppermost mantle depth, the velocity distribution is relatively uniform. The large earthquakes (above Mw 6.0) mainly took place at the edge of the high and low velocity zones.

ABSTRACT

Appraisement of the geologic features as a geo heritage in abu roash area cairo-egypt

Journal: Malaysian Journal of Geosciences (MJG)
Author: Mohamed A. Abdel-Maksou, Kholoud M. Abdel-Maksoud

This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited

DOI: 10.26480/mjg.02.2017.24.28

Egypt contains Geologic Heritage that create much opportunity to develop educational and recreational programs as well as tourism projects. Enhancement of Geologic Heritage and awareness of the importance of Geologic Heritage is a great challenge. This paper focuses on a neglected area inside Cairo that is facing a great destruction from the people living there. The Abu-Roash archaeological site is located at 31ᵒ 02′ 42″ E longitude and 30ᵒ 02′ 42″ N latitude. It is one of the most important areas for education and scientific study inside Cairo. Although the area is not suited as a geo-heritage or even a protected area, it contains Cretaceous to upper Eocene sedimentary beds and fossils, and a great variety of structural features. Not only an important geologic aspect found in the area but also an archeological site is present which provide the area of a great scientific, cultural/historical, aesthetic and/or social/economic value. These different criteria qualifies the study are to have a regional/provincial rank for its Geo-heritage. Abu Roash area are possess good geo-diversity, geo abundance and geo richness which lead us to start point for establishing potential geo-heritage that should be conserved the area also need to be recognized as a geological conservation sites, the area should be Stated as a protected area of a heritage legislation to protect geo-heritage.

ABSTRACT

Flood Potential Analysis (FPAn) using Geo-Spatial Data in Penampang area, Sabah

Journal: Malaysian Journal of Geosciences (MJG)
Author: Rodeano Roslee, Felix Tongkul, Norbert Simon & Mohd. Norazman Norhisham

This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited

DOI: 10.26480/mjg.01.2017.01.06

Flooding is one of the major natural disasters in Sabah, Malaysia. Several recent cases of catastrophic flooding were recorded especially in Penampang area, Sabah (e.g. July 1999; October 2010; April 2013; October & December 2014). Heavy monsoon rainfall has triggered floods and caused great damage in Penampang area. The 2014 floods has affected 40,000 people from 70 villages. The main objective of this study are to analysis the Flood Potential Level (FPL) in the study area. In this study, eigth (8) parameters were considered in relation to the causative factors to flooding, which are: rainfall, slope gradient, elevation, drainage density, landuse, soil textures, slope curvatures and flow accumulation. Flood Potential Analysis (FPAn) map were produced based on the data collected from the field survey, laboratory analysis, high resolution digital radar images (IFSAR) acquisation, and secondary data. FPL were defined using Multi Criteria Evaluation (MCE) technique integrated with GIS software. The information from this paper can contribute to better management of flood disaster in this study area.

ABSTRACT

Attenuation of waves from boat wakes in mixed mangrove forest of rhizophora and bruguiera species in matang perak

Journal: Malaysian Journal of Geosciences (MJG)
Author: Isfarita Ismail, Mohd Lokman Husain, Rozaimi Zakaria

This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited

DOI: 10.26480/mjg.02.2017.29.32

In Malaysia, there are several small rivers and estuaries which are frequented by fishing boats. The wave action due to the movement of boats impact the coastal morphology of the area. In this paper, we have studied the wave reduction in mixed mangrove forest of Rhizosphere and Bruguiera species based on field observations of waves from boat wakes in Sg. Sangga Kecil of Matang forest reserve, west coast of Peninsular Malaysia. The unique physical characteristics of Bruguiera sp. and Rhizophora sp. such as the intricate knee root and numerous pneumatophores, respectively, impact the wave amplitudes in the mangrove forest. The reduction of wave amplitudes in a 15 m long transect of mixed mangrove forest at a given study site has been analysed in the present study. It is found that the wave reduction for each 5-m distance from the vegetation edge ranged from 47.4% to 9.6%. However, on a cumulative basis the wave reduction inside the mixed mangrove forest ranged between 47.4% to 72.8%, with an average of 63%. As far as the vertical trend is concerned the wave reduction in (0-10cm) level was 88.7% while in (10-20cm) level it was found to be 61.2%.

ABSTRACT

Association of Evacuation Dimensions towards Risk Perception of the Malaysian students who studied at Jakarta, Medan, and Acheh in Indonesia

Journal: Malaysian Journal of Geosciences (MJG)
Author: Ahmad Azan Ridzuan, Ungku Azly Ungku Zahar, Noor Akmar Mohd Noor

This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited

DOI: 10.26480/mjg.01.2017.07.12

Disasters can strike anywhere at any time that may result in injuries or loss of life for those individuals who are ill-prepared for disaster situations. Evacuation is a vital part of disaster management. Successful evacuation requires involvement of the community by understanding evacuation orders, knowing evacuation routes and timely decision making to evacuate. This study was conducted to measure the relationship between evacuation dimensions (behavioral, organizational, physical hazard, response, social, and warning) and risk perception using questionnaires gathered from the Malaysian students who studied at Jakarta, Medan, and Acheh in Indonesia. The outcomes of SmartPLS path model showed six important findings: firstly, behavioral not significantly correlated with risk perception. Second, organizational significantly correlated with risk perception. Third, physical hazard significantly correlated with risk perception. Fourth, response significantly correlated with risk perception. Fifth, social significantly correlated with risk perception. Sixth, warning significantly correlated with risk perception. Statistically, this result confirms that the implementation of organizational, physical hazard, response, social, and warning have been important determinant of risk perception. Conversely, the implementation of behavioral had not enhanced the risk perception in the organizational sample. In addition, discussion, implications and conclusion are elaborated.