首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献，搜索用时 31 毫秒
1.
Information on reflected surface gravity waves from the shoreline is required for understanding the coastal hydrodynamics. We have quantified the reflected swells (frequency band 0.045–0.12 Hz) from the west and east coast of India based on the spectral wave data derived from the directional waverider buoys. Reflection coefficient, ratio of the reflected and incident spectral energy, was used to quantify the reflected waves. Influence of the seasons, cyclone, relative depth, land/sea breeze, tides and tidal current on the reflected waves were examined. For the locations off the west coast of India, seasons have large impact on the reflection coefficient and were relatively less during the monsoon season due to the increase in incident wave energy. Locations off the east coast of India show almost the same reflection coefficient throughout the year and have no significant seasonal variations. The reflection coefficient off Puducherry was higher than that for other locations due to the low incident wave energy. The reflection coefficient was low during the cyclone period, but the reflected energy during cyclone was higher than that during the normal condition due to the high incident wave energy. High-energy reflected waves show large variation with tide due to the trapping and dissipation of reflected wave by bottom friction and this effect cause low reflection in deep water location than shallow water location. The reflection coefficient decreases with increase in relative depth off west coast of India.  相似文献   

2.
A very severe cyclonic storm ‘Thane’ developed over the Bay of Bengal during 25–30 December 2011, crossed the Tamilnadu coast between Pondicherry and Cuddalore (southeast coast of India) in early hours of 30 December with a wind speed 120–140 km/h. The offshore tide record reveals that the surge started to generate around 1100 hours on 29 December 2011 with a height 0.4 m and later raised to 0.68 m at the time of land fall, that is, early hours (0000 hours) of 30 December 2011. Field reconnaissance survey on surge run-up and inundation distance at 15 selected locations of cyclone affected areas reveals that the vulnerability levels are highly variable along the coast. The inundation distance extended up to 30–230 m landward from the shoreline and run-up reached to 1.6–3.2 m above chart datum depending upon the cross-shore geometry of the location. In the areas (Verranampattinam, Chinamudaliyar kuppam and Silver beach) near cyclone landfall, the run-up was up to 2.5–3.2 m and the inundation distance extended up to a maximum of 230 m. However, in the areas located about 150 km north of cyclone landfall, the run-up limited from 1.6 to 1.7 m and the inundation distance extended up to only a maximum of 169 m. The inundation distance is mainly influenced by the slope of the beach. In the areas having beach slope between 1 in 135 and 1 in 220, the inundation distance was 210–230 m. However, in the areas having beach slope 1 in 17 to 1 in 34, the inundation distance is restricted between 35 and 50 m.  相似文献   

3.
The cyclone wave parameters are predicted using Young’s parametric hurricane wave prediction model. The input cyclone tracks for this work are obtained from Fleet Naval Meteorology and Oceanography Center, USA. Extreme value analysis is carried out to obtain the wave heights and periods for 1 in 5, 10, 50 and 100 years return periods, respectively. The deep-water hindcast wave corresponding to 100 years from probable directions are allowed to propagate to Visakhapatnam coastal waters using nearshore spectral wind-wave mode. The offshore wave height for one in 100-year return period is 11.9 m, and the corresponding nearshore wave height at 10-m water depth varies between 4.6 and 5.6 m depending on the directional spreading. Weibull distribution is chosen to fit the 24 cyclonic data sets over a total period of 30 years (September 1972 to November 2002). This paper demonstrates usefulness of Young’s wave model for deep-water extreme wave hindcasting. Further, the results of the present study would be highly useful for assessing the design wave height for Visakhapatnam coast.  相似文献   

4.
The December 26, 2004 Sumatra tsunami caused severe damage at the coasts of the Indian ocean. We report results of a sedimentological study of tsunami run-up parameters and the sediments laid down by the tsunami at the coast of Tamil Nadu, India, and between Malindi and Lamu, Kenya. In India, evidence of three tsunami waves is preserved on the beaches in the form of characteristic debris accumulations. We measured the maximum run-up distance at 580 m and the maximum run-up height at 4.85 m. Flow depth over land was at least 3.5 m. The tsunami deposited an up to 30 cm thick blanket of moderately well to well-sorted coarse and medium sand that overlies older beach deposits or soil with an erosional unconformity. The sand sheet thins inland without a decrease of grain-size. The deposits consist frequently of three layers. The lower one may be cross-bedded with foresets dipping landward and indicating deposition during run-up. The overlying two sand layers are graded or parallel-laminated without indicators of current directions. Thus, it remains undecided whether they formed during run-up or return flow. Thin dark laminae rich in heavy minerals frequently mark the contacts between successive layers. Benthic foraminifera indicate an entrainment of sediment by the tsunami from water depths less than ca. 30 m water depth. On the Indian shelf these depths are present at distances of up to 5 km from the coast. In Kenya only one wave is recorded, which attained a run-up height of 3 m at a run-up distance of ca. 35 m from the tidal water line at the time of the tsunami impact. Only one layer of fine sand was deposited by the tsunami. It consists predominantly of heavy minerals supplied to the sea by a nearby river. The sand layer thins landward with a minor decrease in grain-size. Benthic foraminifera indicate an entrainment of sediment by the tsunami from water depths less than ca. 30 m water depth, reaching down potentially to ca. 80 m. The presence of only one tsunami-related sediment layer in Kenya, but three in India, reflects the impact of only one wave at the coast of Kenya, as opposed to several in India. Grain-size distributions in the Indian and Kenyan deposits are mostly normal to slightly positively skewed and indicate that the detritus was entrained by the tsunami from well sorted pre-tsunami deposits in nearshore, swash zone and beach environments.  相似文献   

5.
Response of the coastal regions of eastern Arabian Sea (AS) and Kavaratti Island lagoon in the AS to the tropical cyclonic storm `Phyan??, which developed in winter in the south-eastern AS and swept northward along the eastern AS during 9?C12 November 2009 until its landfall at the northwest coast of India, is examined based on in situ and satellite-derived measurements. Wind was predominantly south/south-westerly and the maximum wind speed (U10) of ~16 m/s occurred at Kavaratti Island region followed by ~8 m/s at Dwarka (Gujarat) and ~7 m/s at Diu (located south of Dwarka) as well as two southwest Indian coastal locations (Mangalore and Malpe). All other west Indian coastal sites recorded maximum wind speed of ~5?C6 m/s. Gust factor (i.e., gust-to-speed ratio) during peak storm event was highly variable with respect to topography, with steep hilly stations (Karwar and Ratnagiri) and proximate thick and tall vegetation-rich site (Kochi) exhibiting large values (~6), whereas Island station (Kavaratti) exhibiting ~1 (indicating consistently steady wind). Rainfall in association with Phyan was temporally scattered, with the highest 24-h accumulated precipitation (~60 mm) at Karwar and ~45 mm at several other west Indian coastal sites. Impact of Phyan on the west Indian coastal regions was manifested in terms of intensified significant waves (~2.2 m at Karwar and Panaji), sea surface cooling (~5°C at Calicut), and moderate surge (~50 cm at Verem, Goa). The surface waves were south-westerly and the peak wave period (T p) shortened from ~10?C17 s to ~5?C10 s during Phyan, indicating their transition from the long-period `swell?? to the short-period `sea??. Reduction in the spread of the mean wave period (T z) from ~5?C10 s to a steady period of ~6 s was another manifestation of the influence of the cyclone on the surface wave field. Several factors such as (1) water piling-up at the coast supported by south/south-westerly wind and seaward flow of the excess water in the rivers due to heavy rains, (2) reduction of piling-up at the coast, supported by the upstream penetration of seawater into the rivers, and (3) possible interaction of upstream flow with river run-off, together resulted in the observed moderate surge at the west Indian coast. Despite the intense wind forcing, Kavaratti Island lagoon experienced insignificantly weak surge (~7 cm) because of lack of river influx and absence of a sufficiently large land boundary required for the generation and sustenance of wave/wind-driven water mass piling-up at the land?Csea interface.  相似文献   

6.
A bottom-mounted Recording Doppler Current Profiler was placed at an offshore location (depth of 34 m) in the southeast Chukchi Sea, Alaska, from July through December 2007 (UTC) with the objective of linking observed wave activity—wind-sea and swells—to their synoptic drivers. A total of 47 intervals of elevated wave state were recorded: 29 exceeding 1 m significant wave height (SWH), 16 exceeding 2 m SWH, and 3 m exceeded on two occasions; during one of those, a SWH of 4 m was observed. Detailed analysis of the two large events, including comparison with high-resolution reanalysis wind data (North America Regional Reanalysis), showed wave direction from the east, varied about 15° to the north (counterclockwise) from the wind direction, and current flow in the opposite direction (from the west). This is thought to be the influence of a strong “wind-sea” presence. Regarding classic wave limitations, although the SE Chukchi Sea is a large embayment bordered by land to the east, fetch limitations from the northeast and southeast did not appear to be a constraint for the wind speeds indicated by reanalysis. These two events appeared to be driven by winds associated with cyclonic systems that moved into the eastern Bering Sea and stalled. Examination of smaller waves associated with these events suggested that waves of 1.5 m SWH or less are likely part of another regime and can either be swell or wind-sea, moving in from the open Chukchi Sea to the northwest or through the Bering Strait to the south.  相似文献   

7.
Bay of Bengal cyclone extreme water level estimate uncertainty   总被引：4，自引：3，他引：1  
  相似文献   

8.
Two bottom-mounted recording Doppler current profilers (RDCP) were deployed at nearshore locations (approximately 3 and 8 km offshore, in about 18 m water depth) in the southeast Chukchi Sea, Alaska, from October 2009 to September 2010 (UTC) with the goal of linking observed wave activity—wind-sea and swells—to their synoptic drivers. The northerly RDCP recorded a total of 16 events of elevated wave states: 15 exceeding 1 m significant wave height (SWH), and 1 exceeding 2 m SWH. The southerly RDCP recorded a total of 25 events of elevated wave states: 23 exceeding 1 m SWH, 2 m exceeded on two occasions and a SWH of 3 m was observed. Detailed analysis of the three large events (i.e., SWH events ≥2 m), including comparison with high-resolution reanalysis wind data (North America regional reanalysis), strongly suggested the wave energy evolved from a distant storm and would be defined as swell. Due to the close proximity of the shoreline to the east of the instruments, wind speeds based on reanalysis were constrained so fetch was westerly. Wave direction was also westerly, varying about 25° to the north (clockwise) or the south (counterclockwise) from the wind direction which is believed to be influenced by fetch and the strong current flow located where the nearshore RDCPs were deployed. Shore-fast sea ice is also believed to play a role but shown to only dampen wave activity for 3 months (January–April 2010), thus implying early ice breakup in this nearshore region. Two events appeared to be driven by southwesterly winds associated with cyclonic systems that moved into the eastern Chukchi Sea and then stalled. However, the second storm event appeared to be driven by northwesterly winds associated with a cyclonic system over the Brooks Range, a less common occurrence. Given that the typical storm activity in the region occurs as storms move into the Bering Sea in fall, this represents another potential source for wave conditions posing danger to people on the water or to coastal infrastructure.  相似文献   

9.
Spectral and statistical wave parameters obtained from the measured time series wave data off Paradip, east coast of India during May 1996–January 1997 were analysed along with MIKE 21 spectral wave model (SW) results. Statistical wave parameters and directional wave energy spectra distinctly separate out the wave conditions that prevailed off Paradip in the monsoon, fair weather and extreme weather events during the above period. Frequency-energy spectra during extreme events are single peaked, and the maximum energy distribution is in a narrow frequency band with an average directional spreading of 20°. Spectra for other seasons are multi-peaked, and energy is distributed over a wide range of frequencies and directions. The NCEP re-analysis winds were used in the model, and the results clearly bring out the wave features during depressions. The simulated wave parameters reasonably show good match with the measurements. For example, the correlation coefficient between the measured and modelled significant wave height is 0.87 and the bias −0.25.  相似文献   

10.
The spectral characteristics of shallow water waves were studied at two locations along the eastern Arabian Sea during 2011. Wave spectra were single-peaked from June to October and predominantly double-peaked during the rest of the year. Even though both locations were subjected to open sea conditions, the percentage of single-peaked spectra was large (63 %) in the southern location compared to a location 350 km north (46 %), because of variation in local winds. Throughout the year, the double-peaked spectra were mostly swell dominated in the southern location. In the northern location, the double-peaked spectra during January to May and December were sea dominated due to the strong local winds blowing from north-west. For the double-peaked wave spectra, the average difference between the spectral peaks was 0.11 Hz, and the average ratio of the spectral energy density at the two peaks was 0.5. Significant wave heights up to 4.2 m and a maximum wave height of 7 m were observed during the south-west monsoon period. Fifty per cent of the waves recorded had spectral peak wave periods between 6 and 12 s. The narrowest directional spectra were found for waves with 10–12-s peak wave periods. Inverse wave age values were biased towards lower values with peaks in the range of 0.2–0.6, indicating a swell-driven wave regime along the eastern Arabian Sea.  相似文献   

11.
The devastation due to storm surge flooding caused by extreme wind waves generated by the cyclones is a severe apprehension along the coastal regions of India. In order to coexist with nature’s destructive forces in any vulnerable coastal areas, numerical ocean models are considered today as an essential tool to predict the sea level rise and associated inland extent of flooding that could be generated by a cyclonic storm crossing any coastal stretch. For this purpose, the advanced 2D depth-integrated (ADCIRC-2DDI) circulation model based on finite-element formulation is configured for the simulation of surges and water levels along the east coast of India. The model is integrated using wind stress forcing, representative of 1989, 1996, and 2000 cyclones, which crossed different parts of the east coast of India. Using the long-term inventory of cyclone database, synthesized tracks are deduced for vulnerable coastal districts of Tamil Nadu. Return periods are also computed for the intensity and frequency of cyclones for each coastal district. Considering the importance of Kalpakkam region, extreme water levels are computed based on a 50-year return period data, for the generation of storm surges, induced water levels, and extent of inland inundation. Based on experimental evidence, it is advocated that this region could be inundated/affected by a storm with a threshold pressure drop of 66 hpa. Also it is noticed that the horizontal extent of inland inundation ranges between 1 and 1.5 km associated with the peak surge. Another severe cyclonic storm in Tamil Nadu (November 2000 cyclone), which made landfall approximately 20 km south of Cuddalore, has been chosen to simulate surges and water levels. Two severe cyclonic storms that hit Andhra coast during 1989 and 1996, which made landfall near Kavali and Kakinada, respectively, are also considered and computed run-up heights and associated water levels. The simulations exhibit a good agreement with available observations from the different sources on storm surges and associated inundation caused by these respective storms. It is believed that this study would help the coastal authorities to develop a short- and long-term disaster management, mitigation plan, and emergency response in the event of storm surge flooding.  相似文献   

12.
Catastrophe risk models are used to assess and manage the economic and societal impacts of natural perils such as tropical cyclones. Large ensembles of event simulations are required to generate useful model output. For example, to estimate the risk due to wind-driven storm surge and waves in tropical cyclone risk models, computationally efficient parametric representations of the wind forcing are required to enable the generation of large ensembles. This paper presents new results on the impact of including explicit representations of extra-tropical transitioning in parametric wind models used to force storm surge and wave simulations in a catastrophe risk modelling context. Extra-tropical transitioning is particularly important in modelling risk on the Japanese coastline, as roughly 40 % of typhoons hitting the Japanese mainland are transitioning before landfall. Using both a historical and idealized track set, we compare maximum storm surge and wave footprints along the Japanese coastline for models that include, and do not include, explicit representations of extra-tropical transitioning. We find that the inclusion of extra-tropical transitioning leads to lower storm surge (10–20 %) and waves (5–15 %) on the southern Japanese coast, with significantly higher storm surge and waves along the northern coast (25–50 %). The results of this paper demonstrate that useful risk assessment of coastal flood risk in Japan must consider the extra-tropical transitioning process.  相似文献   

13.
Both finite-element and finite-difference numerical models are applied to simulate storm surges and associated currents generated by tropical cyclones that struck the coast of Andhra Pradesh, located on the east coast of India. During a cyclone, the total water level at any location on the coast is made up of the storm surge, surge–wind wave interaction and the tide. The advanced circulation two-dimensional depth-integrated (ADCIRC-2DDI) model based on finite-element formulation and the two-dimensional finite-difference model of storm surges developed at IIT Delhi, hereafter referred as IITD storm surge model, are used. These models are driven by astronomical tides at the open ocean boundary and cyclonic asymmetric winds over the surface of the computational domain. Comparison of model simulated sea-surface elevations with coarse and finer spatial resolutions suggests that the grid resolution near the coast is very crucial for accurate determination of the surges in addition to the local bathymetry. The model underpredicts surges, and the peak surge location shifts more to the right of the landfall as the spatial resolution of the model becomes coarser. The numerical experiments also demonstrate that the ADCIRC model is robust over the IITD storm surge model for surge computations as the coastline is better represented in the former.  相似文献   

14.
The prediction of high extremes in sustained water level is very important for coastal engineering design and planning. The recorded historical water level datasets in Colombo, Sri Lanka, are not long enough for the traditional frequency analysis in predicting extreme water levels, such as 50-, 100- and 200-year extreme water levels. In this study, the integrated ADCIRC + SWAN hydrodynamic model and Monte Carlo model have been applied to predict extreme water level in Colombo station of Sri Lanka. The meteorological driving forces of cyclone storm surge are simulated by Monte Carlo stochastic model. The calibrated ADCIRC model with SWAN wave model is used to simulate the potential surge setups with the driving forces generated by Monte Carlo model. By ranking the maximum high water levels in each storm surge procedure, the estimation on extreme high water levels for the desired return period is proposed in this study. The estimated extreme high water levels with return period of 50, 100 and 200 years are 1.28, 1.40 and 1.50 m correspondingly. The estimated extreme high water levels are recommended for engineering design and planning.  相似文献   

15.
During 23–30 September 1997, a rare cyclonic storm has developed close to the Andhra coast, and it has later travelled parallel to coastline northward and finally crossed the land at Chittagong (22°N, 91°E) on 27 September. While translating along the east coast of India, it has produced heavy to very heavy rainfall on the coastal stations causing devastating floods. In this study, we made an attempt to understand the salient causes of this unique cyclone movement. We have analyzed daily fields of wind and relative humidity for 850, 700, 500 hPa and mean daily OLR data to understand the plausible reasons for its movement. The buoy data deployed by National Institute of Ocean Technology, Chennai, Viz. DS5 (15°N, 81°E), DS4 (19°N, 88°E) and SW7 (20°N, 86°E) were analyzed to understand the ocean–atmosphere interaction processes in the west Bay of Bengal during formation of the system. Analysis of OLR over the cyclonic storm region has revealed that the heavy rainfall areas coincide with low OLR (120–180 W m?2). The persistent southward movement of 500 hPa ridge on the eastern wedge of the system along with the steering current at 200 hPa has helped in maintaining the movement of the system parallel to the east coast of India during its life cycle.  相似文献   

16.
Subaerial landslides falling into confined water bodies often generate impulsive waves. Damaging landslide tsunamis in Three Gorges Reservoir, China, have struck several times in the last 15 years. On June 24, 2015, a 23?×?104 m3 slope failure occurred on the east bank of the Daning River opposite Wushan Town. The sliding mass intruded into the Three Gorges Reservoir and initiated a reservoir tsunami that resulted in two deaths and significant damage to shipping facilities. A post-event survey revealed the landslide geometry and wave run-up distribution, while an eyewitness video captured most of the landslide motion. Employing these firm constraints, we applied the Tsunami Squares method to simulate the 2015 Hongyanzi landslide and tsunami. The simulation revealed that the landslide experienced a progressive failure in the first few seconds and impacted the water with a maximum velocity of ~?16 m/s. The initial wave propagated to the opposite shore in an arch shape, and the water surface reached a maximum amplitude of ~?11 m near the landslide. Wave amplitude-time curves at four points on the river cross section show that the initial wave reached Wushan town in about 50 s with an average wave velocity of ~?30 m/s. The maximum wave run-ups on the shoreline opposite the landslide are around 6 m and attenuate to less than 1 m beyond 2-km distance. The landslide simulation matches the observed geological profile and the eyewitness video, and the numerical results coincide with the observed wave run-up heights. Nearly 80% of landslide energy is lost due to frictional resistances, but the remaining fraction imparted to the tsunami carried catastrophic consequences to a large region. The numerical results emphasize the efficiency and accuracy of Tsunami Squares method for a “Quick Look” simulation of a potential landslide.  相似文献   

17.
The Ipswichian high‐tide coast in the Bristol Channel and Severn Estuary at the time of the highest sea‐levels (5–10 m OD) was wave‐dominated almost everywhere. It is defined by raised beaches and inshore sand shoals, and only in comparatively long but narrow inlets (Somerset Levels) are estuarine conditions evident. The modern Holocene seaway is wave‐dominated at high tide only up to and including the inner Bristol Channel. A muddy upper shore typifies the large, tide‐dominated Severn Estuary to the east and northeast. The larger depth and width of the Ipswichian seaway may explain its greater wave‐dominance, but it is also possible that differences in the sediment regime also contribute to the contrast observed. With water levels continuing to rise, the Holocene seaway could reach Ipswichian depths within a few thousand years and evolve toward greater wave‐dominance. A secondary effect may be the transgression and substantial removal of the Holocene estuarine sequence associated with the Severn Estuary Levels. Copyright © 2002 John Wiley & Sons, Ltd.  相似文献   

18.
Monsoon-induced coastal upwelling, land run-off, benthic and atmospheric inputs make the western Indian shelf waters biologically productive that is expected to lead to high rates of mineralisation of organic matter (OM) in the sediments. Dissimilatory sulphate reduction (SR) is a major pathway of OM mineralisation in near-shore marine sediments owing to depletion of other energetically more profitable electron acceptors (O2, NO3 ?, Mn and Fe oxides) within few millimetres of the sediment-water interface. We carried out first ever study to quantify SR rates in the inner shelf sediments off Goa (central west coast of India) using the 35S radiotracer technique. The highest rates were recorded in the upper 10 cm of the sediment cores and decreased gradually thereafter below detection. Despite significant SR activity in the upper ～12 to 21 cm at most of the sites, pore water sulphate concentrations generally did not show much variation with depth. The depth integrated SR rate (0.066–0.46 mol m?2 year?1) decreased with increasing water depth. Free sulphide was present in low concentrations (0–3 μM) in pore waters at shallow stations (depth <30 m). However, high build-up of sulphide (100–600 μM) in pore waters was observed at two deeper stations (depths 39 and 48 m), 7–11 cm below the sediment-water interface. The total iron content of the sediment decreased from ～7 to 5 % from the shallowest to the deepest station. The high pyrite content indicates that the shelf sediments act as a sink for sulphide accounting for the low free sulphide levels in pore water. In the moderately organic rich (2–3.5 %) sediments off Goa, the measured SR rates are much lower than those reported from other upwelling areas, especially off Namibia and Peru. The amount of organic carbon remineralised via sulphate reduction was ～0.52 mol m?2 year?1. With an estimated average organic carbon accumulation rate of ～5.6 (±0.5) mol m?2 year?1, it appears that the bulk of organic matter gets preserved in sediments in the study region.  相似文献   

19.
Every year, Australia experiences tropical cyclones that bring large amounts of rainfall, causing flooding and damage to infrastructure and road closure due to landslips. In March 2017, tropical cyclone Debbie hit the Queensland coast dumping 747 mm of rainfall within 2 days to the Gold Coast region. As a result, multiple shallow landslides occurred in Gold Coast and northern New South Wales due to the increase in soil saturation. A field investigation was conducted from several sites between Gold Coast-Springbrook road and Tallebudgera creek road to identify geological settings and landslide characteristics. Key findings show that slides predominantly occurred in weathered meta-sediments of the Neranleigh-Fernvale Beds within a depth of 1–2 m. Furthermore, a series of shear box tests revealed that the shear strength of the soil significantly decreased when saturation occurred.  相似文献   

20.
Tide gauge data were used to identify the occurrence, characteristics, and cause of tsunamis of meteorological origin (termed ‘meteotsunamis’) along the Western Australian coast. This is the first study to identify meteotsunamis in this region, and the results indicated that they occur frequently. Although meteotsunamis are not catastrophic to the extent of major seismically induced basin-scale events, the wave heights of meteotsunamis examined at some local stations in this study were higher than those recorded through seismic tsunamis. In June 2012, a meteotsunami contributed to an extreme water-level event at Fremantle, which recorded the highest water level in over 115 years. Meteotsunamis (wave heights >0.4 m, when the mean tidal range in the region is ~0.5 m) were found to coincide with thunderstorms in summer and the passage of low-pressure systems during winter. Spectral analysis of tide gauge time series records showed that existing continental seiche oscillations (periods between 30 min and 5 h) were enhanced during the meteotsunamis, with a high proportion of energy transferred to the continental shelf oscillation period. Three recent meteotsunami events (22 March 2010, 10 June 2012, and 7 January 2013) two due to summer thunderstorms and one due to a winter frontal system were chosen for detailed analysis. The meteotsunami amplitudes were up to a factor 2 larger than the local tidal range and sometimes contributed up to 85 % of the non-tidal water signal. A single meteorological event was found to generate several meteotsunamis along the coast, up to 500 km apart, as the air pressure disturbance propagated over the continental shelf; however, the topography and local bathymetry of the continental shelf defined the local sea-level resonance characteristics at each location. With the available data (sea level and meteorological), the exact mechanisms for the generation of the meteotsunamis could not be isolated.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号