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海权论与和谐海洋大战略观   总被引:1,自引:1,他引:0  
21世纪是海洋世纪。在当今和平的时代里,国家与国家之间的竞争,主要表现在能源等资源的竞争.人与自然的和谐发展以及科学技术的进步,如何用和平的手段去获取国家海洋的控制权益.提高国家的综合竞争能力,兵不血刃而达到目的,是我国重要的海洋战略。论文结合马汉的海权论,海洋新世纪的发展趋势,论述了构建当代我国和谐海洋大战略观及对海洋的控制权益。  相似文献   

3.
在丰富的可供开发的海洋旅游资源中,由于一些"海洋灾害"能够满足旅游者求异、探险等多方面的旅游需求,能够给旅游者带来"壮美"旅游体验,使其实现自我超越,因而促成了新的海洋旅游产品——"海洋灾害"旅游。其实质是通过恰当的旅游形式对可用作旅游资源的海洋灾害进行的旅游活动,这些旅游资源不仅包括海洋灾害本身(如台风、海啸等)、以海洋灾害为旅游内容建设的主题公园等,还包括因海洋灾害给人类带来的灾难或引致事故产生的遗址、纪念地等。该文基于旅游体验理论确定了"海洋灾害"旅游开发的可行性,并针对海洋灾害的特点分析现阶段与之相适应的旅游体验开发方式,即旅游景观吸引系统的博物馆化和主题公园建设,并提出旅游消费者心理需求、安全保障系统、科学技术手段、宣传促销等是对海洋灾害进行旅游开发的关键要素。  相似文献   

4.
Summary. Rayleigh-wave phase velocities at very long periods (185–290 s) are investigated and regionalized, taking into account the lateral heterogeneities within ocean plates revealed by earlier studies at shorter periods. The two-station method is applied to a few 'pure-age' oceanic paths, and is shown to be compatible with the average Earth model C2 (Anderson & Hart 1976) below depths of 180 km. Under this assumed oceanic model, regionalized for age above 180 km, continental velocities are then derived from a set of experimental great-circle values, both new or taken from previously published studies. The results basically agree with earlier studies (Dziewonski 1970; Kanamori 1970), although they exhibit less scatter than Kanamori's model. Results are successfully checked against a set of values derived by the two-station method from a pure continental path.
Although the shield velocities are substantially different from the mean oceanic ones, they still fall within the range of variation of oceanic velocities with the age of the plate. This makes velocities derived theoretically from Jordan's (1975a, b) models of deep continent—ocean lateral heterogeneities, inconsistent with the present set of experimental data. Finally, we show that Dziewonski's (1971) model S2 reconciles all experimental seismic data relative to shields, without being significantly different from oceanic models below 240 km.  相似文献   

5.
Velocity and mass fields from a constant-density, near-global ocean model, driven with observed twice-daily surface wind stresses and atmospheric pressures for the period October 1992-September 1993, are used to calculate oceanic excitation functions for the length of day (LOD) and for polar motion (PM), and results are analysed as a function of the frequency band. Variable currents and mass redistributions are both important in determining oceanic excitation functions. For bands with periods longer than one month, wind-driven variability is the primary cause of oceanic excitation signals. At higher frequency bands, larger deviations from the inverted barometer response occur, and pressure-driven signals contribute more significantly to the variance in the excitation functions. Oceanic LOD excitation is generally small compared to that of the atmosphere, except for the 2-10 day band. At these scales, adding oceanic to atmospheric excitation series does not lead to better agreement with the observed LOD, although this result may be related to data quality issues. With regard to the excitation of PM, the ocean is in general as important as the atmosphere at most time scales. Combined oceanic and atmospheric excitation series compare visibly better with geodetic series than do atmospheric series alone, pointing to the ocean as a source of measurable signals in PM.  相似文献   

6.
试论海洋经济地理学   总被引:4,自引:0,他引:4  
作者认为海洋经济地理学属于经济地理学范畴,其研究对象为海洋产业布局,以及海洋经济体系的形成过程、结构特点和发展规律。海洋产业可分为传统的、新兴的和未来的三种,作者探讨了它们的内容及其与国民经济建设的关系。我国海洋经济地理学研究的重点,80年代以海岸带、90年代以海岛为主,以后将以大陆架和专属经济区为主。海洋经济地理学的研究方法以系统方法为主,文章结合作者住长山群岛的实践,阐述了海洋开发的若干问题,提出开展海洋经济地理研究的同时,要开展更广泛的海洋人文地理研究。  相似文献   

7.
基于来自ECMWF的资料将1957年09月---2002年08月风浪、涌浪分离的ERA-40 wave reanalysis,对全球海域的波浪能资源进行重新审视.充分依据涌浪具有能量大、稳定性好等优点,利于波浪能的采集与转换,从提高波浪能资源有效利用率的角度出发,综合考虑能流密度的大小、能级频率、能流密度的稳定性和长期变化趋势等,对全球海域的波浪能资源进行系统性研究,并构建一套波浪能资源评估系统,对全球海域的波浪能资源进行功能区划,为海浪发电、海水淡化等波浪能资源开发工作提供科学依据.  相似文献   

8.
Summary. The temperature field and rates of cooling and solidification of the oceanic crust and upper mantle at an ocean ridge have been calculated as a function of spreading rate. The thermal model of the accretion process incorporates latent heat release associated with solidification of the basalt. liquid forming the ocean crust and uses a heat supply boundary condition on the vertical ridge axis model boundary. It is assumed that while oceanic layer 2 cools rapidly by hydrothermal circulation, oceanic layer 3 cools predominantly by conduction. Basalt liquid injection into the upper part of oceanic layer 3 is shown to solidify instantaneously while that injected into lower crustal levels takes up to 0.4 Myr to solidify. Material solidifying instantaneously is interpreted as corresponding to the dolerite unit of the ocean crust while that taking a finite time to cool is interpreted as corresponding to the gabbroic unit. The rate of cooling of the crust is shown to be faster for slower spreading rates and consequently the thicknesses of the dolerite and gabbro units are predicted to thin and thicken respectively with increase in spreading rate. The width of the molten region, or magma chamber, within the crust at the ridge axis is shown to be approximately proportional to spreading rate with chamber half widths of 1.5 and 10.0 km for half spreading rate of 1.0 and 6.0 cm yr−1. Below a critical half spreading rate of about 0.65 cm yr−1 no molten region exists and the crust is entirely doleritic.  相似文献   

9.
The devastation caused by the 2004 Indian Ocean tsunami in Sri Lanka is represented as a ‘natural disaster’. Yet, the tsunami did not occur in a sociopolitical and historical vacuum. How people responded to the tsunami, the challenges of and attitudes to relocation and post‐tsunami livelihoods, were/are shaped by uneven development, social exclusion and ethnonationalist war. All these responses are embedded in structures of gender, caste, class, and ethnicity. The tsunami, thus, brought to the forefront preexisting inequalities, showing up complexities in the temporality of disasters. Drawn from fieldwork in two coastal areas in the Southern and Eastern provinces, this paper shows how gendered structures within the local political economy influenced the ways that institutional actors as well as the displaced communities and women initially devised livelihood strategies. These reactions show how place matters as much as preexisting gendered political economy conditions and reveal the complex ways in which women continue to mediate and negotiate everyday responses in the aftermath of a ‘natural’ disaster.  相似文献   

10.
摘 要:21世纪是海洋的世纪,如何营造良好的海洋地缘环境和应对海洋地缘关系中的不断演变的冲突和争端,直接关系到一国在海洋地缘关系中所处的地位,影响着整个国家的发展。近些年来,随着中国经济持续稳定快速发展,全面走向海洋并把中国建设成为海洋强国是我国持续发展的必然趋势。本文基于海洋地缘关系相关理论,分别从黄海、东海、南海和日本海出发,侧重从时空层面探讨研究中国与周边国家海洋地缘关系的历史演变、现状和空间格局,分析其影响因素,最后提出中国周边海洋地缘战略,为我国的海洋建设提供理论支撑。  相似文献   

11.
After the Indian Ocean tsunami of 2004 a number of academics published texts in attempts to make sense of the disaster. Frustrations and feelings of inability to do something useful to assist were expressed. The academic discussions arising from the disaster may be linked with more general discussions around conducting relevant and responsible research in the social sciences. This paper addresses the role of researchers in the aftermath of the tsunami disaster in Sri Lanka and explores how the debate following the tsunami can move on to refine researchers' roles in geography by way of participatory action research (PAR), a research strategy that has received limited attention in research on disasters. The paper begins by situating the debate in the spatial politics of humanitarian work and academic research. Then discussions that arose among geographers in the aftermath of the tsunami are presented and potentials for conducting responsible research by engaging with the field are introduced. In the final section, starting with the notion of responsible research, how PAR can potentially bring us forward in developing principles and tools for more responsible geographical research in the context of emergencies is discussed.  相似文献   

12.
Further evidence for oceanic excitation of polar motion   总被引:3,自引:0,他引:3  
While the role of the atmosphere in driving variations in polar motion is well established, the importance of the oceans has been recognized only recently. Further evidence for the role of the oceans in the excitation of polar motion is presented. To estimate the equatorial excitation functions, χ 1 and χ 2 , for the ocean, we use velocity and mass fields from a constant-density ocean model, driven by observed surface wind stresses and atmospheric pressure, for the period 1993–1995; comparison with similar functions derived from a more complex density-stratified ocean model indicates the effectiveness of the simple constant-density modelling approach. Corresponding atmospheric excitation functions are computed from NCEP/NCAR re-analyses. Results indicate significant improvements in the agreement with the observed polar motion excitation when the simulated oceanic effects are added to atmospheric excitation. Correlations between the polar motion and the geophysical signals at periods of 15–150 days increase from 0.53 to 0.80 and from 0.75 to 0.88 for χ 1 and χ 2 , respectively. The oceanic signals are particularly important for seasonal variations in χ 1 (correlation increases from 0.28 to 0.85 when oceanic excitation is included). A positive impact of the oceans on more rapid polar motion is also observed, up to periods as short as 5 days. The sensitivity of the results to different forcing fields and different amounts of friction in the oceans is also discussed.  相似文献   

13.
Summary. Various numerical procedures have been developed to study the electric currents which are produced by induction in the ocean. In nearly all these methods difficulties arise near the coastline where the electric field changes significantly over a small distance. In this paper a new one-sided correction for the electric field near the edge of the ocean is obtained. The results contain a multiplicative constant which may be determined by a suitable matching technique at an oceanic point. The anomalous magnetic field due to this edge correction is also given.  相似文献   

14.
This paper describes a method for determining Moho depth, lithosphere thinning factor (γ= 1 − 1/β) and the location of the ocean–continent transition at rifted continental margins using 3-D gravity inversion which includes a correction for the large negative lithosphere thermal gravity anomaly within continental margin lithosphere. The lateral density changes caused by the elevated geotherm in thinned continental margin and adjacent ocean basin lithosphere produce a significant lithosphere thermal gravity anomaly which may be in excess of −100 mGal, and for which a correction must be made in order to determine Moho depth accurately from gravity inversion. We describe a method of iteratively calculating the lithosphere thermal gravity anomaly using a lithosphere thermal model to give the present-day temperature field from which we calculate the lithosphere thermal density and gravity anomalies. For continental margin lithosphere, the lithosphere thermal perturbation is calculated from the lithosphere thinning factor (γ= 1 − 1/β) obtained from crustal thinning determined by gravity inversion and breakup age for thermal re-equilibration time. For oceanic lithosphere, the lithosphere thermal model used to predict the lithosphere thermal gravity anomaly may be conditioned using ocean isochrons from plate reconstruction models to provide the age and location of oceanic lithosphere. A correction is made for crustal melt addition due to decompression melting during continental breakup and seafloor spreading. We investigate the sensitivity of the lithosphere thermal gravity anomaly and the predicted Moho depth from gravity inversion at continental rifted margins to the methods used to calculate and condition the lithosphere thermal model using both synthetic models and examples from the North Atlantic.  相似文献   

15.
本文讨论了大洋风场,风应力和某些大气动力学特征,并介绍了需要计算的近海面大气运动学和动力学的量值,特别是风应力的计算方法,最后给出了利用迄今全球大洋最完善的COADS资料求得的大洋风应力和合成风的计算与分析个例.  相似文献   

16.
湛港-腹生产力结构主要是指由广东湛江地区港口和港口城市与海洋和大西南陆地两个腹地连接所形成的生产力区域结构。优化湛港-腹生产力结构具有独特的外在条件和强烈的内在要求。必须开辟湛江海洋型经济产业开发带,建立一个由沿海开放城市推动原料产地发展的外向型海洋经济地域结构,作为粤西、大西南经济发展的重要纽带和桥梁。  相似文献   

17.
A global estimate of the absolute oceanic general circulation from a geostrophic inversion of in situ hydrographic data is tested against and then combined with an estimate obtained from TOPEX/POSEIDON altimetric data and a geoid model computed using the JGM-3 gravity-field solution. Within the quantitative uncertainties of both the hydrographic inversion and the geoid estimate, the two estimates derived by very different methods are consistent. When the in situ inversion is combined with the altimetry/geoid scheme using a recursive inverse procedure, a new solution, fully consistent with both hydrography and altimetry, is found. There is, however, little reduction in the uncertainties of the calculated ocean circulation and its mass and heat fluxes because the best available geoid estimate remains noisy relative to the purely oceano-graphic inferences. The conclusion drawn from this is that the comparatively large errors present in the existing geoid models now limit the ability of satellite altimeter data to improve directly the general ocean circulation models derived from in situ measurements. Because improvements in the geoid could be realized through a dedicated spaceborne gravity recovery mission, the impact of hypothetical much better, future geoid estimates on the circulation uncertainty is also quantified, showing significant hypothetical reductions in the uncertainties of oceanic transport calculations, Full ocean general circulation models could better exploit both existing oceanographic data and future gravity-mission data, but their present use is severely limited by the inability to quantify their error budgets.  相似文献   

18.
刘锡清  刘洪滨 《地理研究》2008,27(1):119-127
岛屿对于发展海洋经济,确定海洋权属,以及国家安全等方面都具有重要地位。因此,岛屿的成因分类研究具有重要理论意义和应用价值。传统上将岛屿分为大陆岛、海洋岛(火山岛与珊瑚岛)和冲积岛。这种分类已经不能适应现代地球学科的新进展。本文根据板块构造理论和大洋地貌体系,提出新的岛屿分类意见,即分为内力和外力两个成因系列,包括近岸大陆岛、隆起大陆岛、大陆火山岛、岛弧陆块岛、岛弧火山岛、俯冲增生岛、无震海岭火山岛、微型陆块岛、海山火山岛、中脊火山岛、构造断层岛、河口沙岛、障壁岛、侵蚀沙岛、珊瑚岛15个类型。  相似文献   

19.
Summary. The deep structure of the Faeroe–Shetland Channel has been investigated as part of the North Atlantic Seismic Project. Shot lines were fired along and across the axis of the Channel, with recording stations both at sea and on adjacent land areas. At 61°N, 1.7 km of Tertiary sediments overlies a 3.9–4.5 km s-1 basement interpreted as the top of early Tertiary volcanics. A main 6.0–6.6 km s-1 crustal refractor interpreted as old oceanic crust occurs at about 9 km depth. The Moho (8.0 ° 0.2 km s-1) is at about 15–17 km depth. There is evidence that P n may be anisotropic beneath the Faeroe–Shetland Channel. Arrivals recorded at land stations show characteristics best explained by scattering at an intervening boundary which may be the continent–ocean crustal contact or the edge of the volcanics.
The Moho delay times at the shot points, determined by time-term analysis, show considerable variation along the axis of the Channel. They correlate with the basement topography, and the greatest delays occur over the buried extension of the Faeroe Ridge at about 60° 15'N, where they are nearly 1 s more than the delays at 61°N after correction for the sediments. The large delays are attributed to thickening of the early Tertiary volcanic layer with isostatic downsagging of the underlying crust and uppermost mantle in response to the load, rather than to thickening of the main crustal ayer.
The new evidence is consistent with deeply buried oceanic crust beneath the Faeroe–Shetland Channel, forming a northern extension of Rockall Trough. The seabed morphology has been grossly modified by the thick and laterally variable pile of early Tertiary volcanic rocks which swamped the region, accounting for the anomalous shallow bathymetry, the transverse ridges and the present narrowness of the Channel.  相似文献   

20.
Low-lying atoll islands appear highly vulnerable to the effects of climate change and extreme natural events. Potentially disastrous effects of future sea-level rise have been inferred in many studies, and the actual impacts of tropical storms on island destruction and formation have been well documented. In contrast, the role of tsunami in the geomorphic development of atoll islands has not been investigated. The Sumatran earthquake of 26 December 2004 generated a tsunami that reached the Maldives 2500 km away, with waves up to 2.5 m high. Observations on the geomorphic changes resulting from the tsunami are detailed here, based on pre-and post-tsunami profile measurements of island, beach and reef topography, and GPS surveys of the planform shape of islands and beaches of 11 uninhabited islands in South Maalhosmadulu atoll, Maldives. Erosional and depositional impacts were observed on all islands and these have been quantified. In general the changes were of a minor nature with a maximum reduction in island area of 9% and average of 3.75%. Rather, the tsunami accentuated predictable seasonal oscillations in shoreline change, including localised erosion reflected in fresh scarps and seepage gullies. Depositional features in the form of sand sheets and sand lobes emplaced on the vegetated island surfaces provide clear evidence that the tsunami waves washed over parts of all the islands. Both erosional scarps and overwash deposits were concentrated at the tsunami-exposed eastern sides of the islands. Impacts on leeward shores were primarily accretionary, in the form of spit and cuspate foreland extension. Whereas the nature and magnitude of intra-and inter-island impacts was variable, an east to west decline in aggregate effects was noted. Detailed consideration of the morphodynamic interaction between the tsunami waves and island morphology, show that this cross-atoll gradient resulted not just from the reduction in tsunami energy as it passed through the atoll, but also from variations in elevation of the encircling island ridge, and the quantity and distribution of sediment in the antecedent beach. A conceptual model identifying the sequence of changes to individual islands supports the observational data and the pattern of geomorphic changes resulting from the tsunami. This model leads to consideration of the longer-term impacts of the tsunami on the future stability of islands. Four scenarios are presented, each of which has a different island-beach sediment budget, and different relaxation time to achieve dynamic equilibrium.  相似文献   

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