11 research outputs found
KIẾN TẠO HIỆN ĐẠI VÀ CÁC TAI BIẾN ĐỊA CHẤT LIÊN QUAN Ở VÙNG BIỂN VIỆT NAM VÀ LÂN CẬN
Get PDFSUMMARY Neotectonics and geological hazards in Vietnam Sea and surroundings This paper presents velocities of present-day tectonic movements in Vietnam and surroundings determined from GPS campaigns from 2007 to 2010. Absolute displacements and velocities of GPS stations in the IGS05 frame were determined. The result indicates that Lang station (LANG) moves eastward with slip rate of ~39mm/yr, southward with slip rate of ~11 mm/yr. The rate of Bach Long Vi (BLV1) is ~30mm/yr for the eastern component and ~11mm/yr for southern component. Song Tu Tay (STT1) moves eastwards with the rate of ~24mm/yr and southwards of 8mm/yr. Con Dao (CDA1) moves to the east with the rate of ~22mm/yr and to the south with the rate of ~6mm/yr. Dong Hoi (DOHO) move to the east with the rate of ~27mm/yr and to the south with the rate of ~8mm/yr. Hue (HUES) moves to the east with the rate of ~30 mm/yr and to the south with the rate of ~12mm/yr. HOCM move to the east with the rate of ~22mm/yr and to the south with the rate of ~10mm/yr. Calculate errors for both direction vary in 0.6 - 1mm/y. Based on seismic profiles, focal mechanisms and regional stress field, several fault segments in Pliocene - Quaternary sediments in East Vietnam Sea has been identified in Red River, Cuu Long and Nam Con Son basins with maximum of 15 km in length. Actual stress regimes in Vietnam and south Hainan basins being transitional demonstrate no source of large tsunami closing to Vietnam shelf. The subduction zone located at north Borneo is not active at present. Only Manila subduction zone is the source for large tsunami in East Vietnam Sea. Based on gravimetric field, topography, distribution of focal mechanisms in various depths and the rate of actual tectonic movement, 5 fault zones of the Manila subduction zone have been divided. The fault zones F3 and F4 can produce respectively maximum earthquake of 8.1 and 8.4. Modeling of displacement of fault zone F4 from the depth 15 to 20 km, 2m high of tsunami at Quang Ngai can be occurred. The depth of tsunami flood can be up to 4-5 m at some places in Quang Ngai and Da Nang
Regional cluster of high sex ratio at birth in 2006–2007 in North Viet Nam.
No full text<p>The high-SRB regional cluster consists of provinces with SRB higher than average that are also surrounded by provinces with high SRB. The clustering's geostatistical significance is tested with the local indicator of spatial association (9999 permutations and p<.01).</p
Sex ratio at birth in 1999–2007.
No full text<p>Annual survey estimates are based on the births during the previous year and start with the initial sample data from the 1999 census. Birth history data are based on the averaged retrospective SRB values available from the last two population surveys. Estimates from the surveys of births are available only for 2006 and 2007.</p
Sex ratio at birth in various subpopulations, Viet Nam, 2006 and 2007 population surveys.
No full text<p>Data from the 2006 or 2007 surveys pertain to the three years before the survey.</p><p>Statistical significance of the chi-square test: * p<.10 **p<.05.</p
