Field survey of the 1994 Mindoro Island,Philippines tsunami   总被引：2，自引：0，他引：2  

Fumihiko Imamura  Costas E. Synolakis  Edison Gica  Vasily Titov  Eddie Listanco  Ho Jun Lee 《Pure and Applied Geophysics》1995,144(3-4):875-890

This is a report of the field survey of the November 15, 1994 Mindoro Island, Philippines, tsunami generated by an earthquake (M=7.0) with a strike-slip motion. We will report runup heights from 54 locations on Luzon, Mindoro and other smaller islands in the Cape Verde passage between Mindoro and Luzon. Most of the damage was concentrated along the northern coast of Mindoro. Runup height distribution ranged 3–4 m at the most severely damaged areas and 2–4 in neighboring areas. The tsunami-affected area was limited to within 10 km of the epicenter. The largest recorded runup value of 7.3 m was measured on the southwestern coast of Baco Island while a runup of 6.1 m was detected on its northern coastline. The earthquake and tsunami killed 62 people, injured 248 and destroyed 800 houses. As observed in other recent tsunami disasters, most of the casualties were children. Nearly all eyewitnesses interviewed described the first wave as a leading-depression wave. Eyewitnesses reported that the main direction of tsunami propagation was SW in Subaang Bay, SE in Wawa and Calapan, NE on Baco Island and N on Verde Island, suggesting that the tsunami source area was in the southern Pass of Verde Island and that the wave propagated rapidly in all directions. The fault plane extended offshore to the N of Mindoro Island, with its rupture originating S of Verde Island and propagating almost directly south to the inland of Mindoro, thereby accounting for the relatively limited damage area observed on the N of Mindoro.  相似文献   

海南什统萤石矿床地质特征     

覃海灿  张小文  傅杨荣  纪明秀  古志祥  杨昌松 《矿产与地质》2005,19(4):398-402

什统萤石矿床位于海南省白沙拗陷带与五指山隆起的接触部位,是以断裂控矿为主的大型萤石矿床,其容矿构造为NE向张扭性断裂,成矿围岩为二长花岗岩和结晶灰岩.笔者以现场地质事实为依据,细致地研究该区的矿床地质特征,为今后的萤石矿床地质探矿提供了理论依据.  相似文献   

ARE ISLANDERS INSULAR? A PERSONAL VIEW*     

KENNETH R. OLWIG 《Geographical review》2007,97(2):175-190

ABSTRACT. I use my personal experience as an islander doing fieldwork among islanders in the West Indies to explore the meaning of “insularity.” I then expand on that personal experience by drawing on literary sources, particularly Homer's the Odyssey and Herman Melville's Moby Dick, both of which express an island worldview. The island worldview is contrasted and compared with the continental worldview on the basis of differing modes of navigation and cartography and differing modes of orientation as defined by cognitive psychologists.  相似文献   

Application of integrated methods in mapping waste disposal areas   总被引：2，自引：0，他引：2  

Pantelis Soupios  Nikos Papadopoulos  Ilias Papadopoulos  Maria Kouli  Filippos Vallianatos  Apostolos Sarris  Thrassyvoulos Manios 《Environmental Geology》2007,53(3):661-675

An integrated suite of environmental methods was used to characterize the hydrogeological, geological and tectonic regime of the largest waste disposal landfill of Crete Island, the Fodele municipal solid waste site (MSW), to determine the geometry of the landfill (depth and spatial extent of electrically conductive anomalies), to define the anisotropy caused by bedrock fabric fractures and to locate potential zones of electrically conductive contamination. A combination of geophysical methods and chemical analysis was implemented for the characterization and management of the landfill. Five different types of geophysical surveys were performed: (1) 2D electrical resistance tomography (ERT), (2) electromagnetic measurements using very low frequencies (VLF), (3) electromagnetic conductivity (EM31), (4) seismic refraction measurements (SR), and (5) ambient noise measurements (HVSR). The above geophysical methods were used with the aim of studying the subsurface properties of the landfill and to define the exact geometrical characteristics of the site under investigation.  相似文献   

Quantitative analysis of soft-bottom molluscs in the Bellingshausen Sea and around Peter I Island   总被引：2，自引：0，他引：2  

Jesús S. Troncoso  Cristian Aldea  Patrick Arnaud  Ana Ramos  & Francisco García 《Polar research》2007,26(2):126-134

  相似文献   

辽东半鸟南部寒武系与奥陶系的界线     

关培彦  李超英 《地质通报》2002,21(2):95-97

在辽南瓦房店市长兴岛镇二龙山、长岭子等地的寒武纪—奥陶纪冶里组上部首次发现Saukia,Calvinella等属种的化石,确定了Saukia—Calvinella组合带,为晚寒武世凤山阶最顶部的化石带。此外在该带之上采到了微体化石Ulahconusbeimadaoensis,该化石属种为奥陶纪早期的标准分子。据此重新厘定了辽南地区寒武系与奥陶系的界线。  相似文献   

Quantitative models for reconstructing catchment ice-extent using physical-chemical characteristics of lake sediments     

P.E. Noon  H.J.B. Birks  V.J. Jones  J.C. Ellis-Evans 《Journal of Paleolimnology》2001,25(3):375-392

The physical characteristics of surface sediments from a suite of pristine lakes on Signy Island, maritime Antarctic, were used to develop a quantitative link between catchment ice-extent and lake-sediment response. Percentage dry weight, median particle size, percentage loss-on-ignition and wet density of the lakes' surface sediments were the most significant variables explaining contemporary catchment ice-extent. Two independent reconstruction models – Partial Least Squares (PLS) and a Modern Analog Technique (MAT) – were applied to dated sediment cores at two sites on Signy Island. The validity of the reconstructions was tested against historical information on catchment ice-extent. With sufficiently high sedimentation rates and sampling resolution, the models can predict sub-decadal changes in ice-extent. The model results are best regarded as indicators of erosion resulting from meltwater activity in the catchment. Comparison of results with Twentieth Century climate records affirms the hypothesis that climatic warming is the most likely cause for the ice retreat observed on Signy Island during the last 40 yrs. Similar reconstruction models using these simple sedimentary measures could be developed for analogous locations in the Antarctic and in Arctic and Alpine regions.  相似文献   

Quaternary vertical offset and average slip rate of the Nojima Fault on Awaji Island, Japan   总被引：5，自引：0，他引：5  

Akihiro Murata  Keiji Takemura  Takao Miyata  Aiming Lin 《Island Arc》2001,10(3-4):360-367

Abstract Drilling was carried out to penetrate the Nojima Fault where the surface rupture occurred associated with the 1995 Hyogo-ken Nanbu earthquake. Two 500 m boreholes were successfully drilled through the fault zone at a depth of 389.4 m. The drilling data show that the relative uplift of the south-east side of the Nojima Fault (south-west segment) was approximately 230 m. The Nojima branch fault, which branches from the Nojima Fault, is inferred to extend to the Asano Fault. From the structural contour map of basal unconformity of the Kobe Group, the vertical component of displacement of the Nojima branch–Asano Fault is estimated to be 260–310 m. Because the vertical component of displacement on the Nojima Fault of the north-east segment is a total of those of the Nojima Fault of the south-west segment and of the Nojima branch–Asano Fault, it is estimated to total to 490–540 m. From this, the average vertical component of the slip rate on the Nojima Fault is estimated to be 0.4–0.45 m/10³ years for the past 1.2 million years.  相似文献   

Recent sedimentation in a high arctic lake, northern Ellesmere Island, Canada     

Bern Zolitschka 《Journal of Paleolimnology》1996,16(2):169-186

A multiple core study was conducted on laminated minerogenic sediments from Lake C2, Northern Ellesmere Island, Canadian High Arctic. Lateral persistence, distal thinning, variation in grain size of these laminations as well as present-day processes of highly seasonal sediment transfer into the lake basin suggest that clastic varves have been formed. Sedimentation rates based on ²¹⁰Pb dating agree well with sedimentation rates based on lamination counts giving further evidence that laminations are annual. Errors in varve counting were reduced from 12% to < 2% using the multi-core approach of cross-correlating all records. Varved sediments are occasionally interrupted by thick coarse-grained layers, which are interpreted as deposits of turbidity currents and may be related to extremely high discharge events and slope failures of the delta front. Micro-laminated sediments spanning the last two centuries were studied in detail. Suspension settling is the dominant process of deposition depending upon stream discharge which is controlled by nival melt and summer temperatures. Application of varve chronology thus allows to use lamination thickness measurements as source of high resolution proxy data for palaeoclimatic reconstruction.This is the fifth in a series of papers published in this issue on the Taconite Inlet Lakes Project. These papers were collected by Dr R. S. Bradley.  相似文献   

The late Quaternary development of three ancient tarns on southwestern Cumberland Peninsula, Baffin Island, Arctic Canada: paleolimnological evidence from diatoms and sediment chemistry     

Alexander P. Wolfe  Joachim W. Härtling 《Journal of Paleolimnology》1996,15(1):1-18

Sediment diatom and chemical analyses of cores from three poorly buffered extra-glacial lakes on the northeastern margin of the Canadian Shield (Cumberland Peninsula, Baffin Island) record interactions between aquatic and terrestrial spheres that were influenced by late Quaternary climatic conditions. Although differences exist between each of the lakes, notably with regards to the intensity of pre-Holocene catchment erosion and the timing of the onset of organic sedimentation, an underlying pattern of lake ontogeny, common to all three lakes, is identified. Although intensified watershed erosion characterized the Late Wisconsinan and Neoglacial cold periods, the lakes nonetheless remained viable ecosystems at these times. Sudden catchment stabilization during the late-glacial to earliest Holocene is associated with incipient organic sedimentation. Lake-water pH increased at this time, likely in response both longer base cation residence times as lake flushing rates decreased, and enhanced alkalinity production from sediment biogeochemical reactions. Subsequently, as the catchments remained stable during the productive early Holocene (c.9–7 ka BP), then gradually received a renewed increase of minerogenic sedimentation, the breakdown of sources of lake alkalinity resulted in natural acidification. Burial of cation-rich mineral sediments and the loss of permanent sedimentary sinks for the products of microbial reduction likely impeded within-lake alkalinity production, and catchment-derived base cations appeared ineffective in curtailing pH declines. The general nature of the Holocene development of these lakes is similar to that observed elsewhere on crystalline terrains, following deglaciation. Our data therefore suggest that catchment glaciation is not a necessary precursor for models of lake development characterized by initial base cation enrichment and subsequent gradual acidification.  相似文献