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4/12/2016
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• Wave definition, types of waves, orbital waves• Why study waves?• Wave parts, anatomy of a wave• How waves begin, generating force, restoring force• Wave Speed: R=D/T or C=L/T, Celerity• Water motion in waves• Wave base, L/2• Deep water waves, intermediate and shallow water waves• Wind generated waves, H dependent on WfD• Wave types: Sea, Swell and Surf• Waves as they approach the shore: refraction, diffraction and reflection• Canyon divergence and headland convergence• Sea caves, arches and sea stacks• Wave generated currents: longshore and rip• Standing waves: nodes and antinodes, seiches• Catostrophic waves: storm surges and tsunamis• Mega tsunamis: know H, L and P of a typical seismic sea wave!• Internal waves
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Fig. 19‐8, p.571
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• Wave definition, types of waves, orbital waves• Why study waves?• Wave parts, anatomy of a wave• How waves begin, generating force, restoring force• Wave Speed: R=D/T or C=L/T, Celerity• Water motion in waves• Wave base, L/2• Deep water waves, intermediate and shallow water waves• Wind generated waves, H dependent on WfD• Wave types: Sea, Swell and Surf• Waves as they approach the shore: refraction, diffraction and reflection• Canyon divergence and headland convergence• Sea caves, arches and sea stacks• Wave generated currents: longshore and rip• Standing waves: nodes and antinodes, seiches• Catostrophic waves: storm surges and tsunamis• Mega tsunamis: know H, L and P of a typical seismic sea wave!• Internal waves
Standing Waves
https://www.youtube.com/watch?v=bYI1zIjJr4g
Hurricanes cyclones and storms bring waves and coastal flooding
STORM SURGES
Hurricane Andrew
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Storm in Bangladesh in April 1991~138,000 killed, 10 million left homeless, 6 meter storm surge goes inland,
1.5 billion in damage
Hurricane Katrina8/28/05
Superstorm Sandy 10/28/12 Typhhon Haiyan 11/8/13
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http://ulithimarineconservation.ucsc.edu/ Tsunami reporting stations and subduction zones
Tsunamis
DART: Deep‐Ocean Assessment and Reporting of Tsunamis
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9.1 – 9.3 Magnitude Sumatran Earthquake Dec. 26, 2004
• Plates‐Boundary Type
• Depth: 30km
• Rupture Length and shaking duration: ~1,300Km (810mi), over 4 min in 1 area, up to 10min total
• Displacement: lateral ~20m, vertical 2‐5m
• Energy Released: ~475 megatons of TNT or 23,000 A‐Bombs
Areas at Risk
– Hawaii
– Alaska
– California
– East Coast US?
– Gulf Coast US?
Earthquake activity in Japan from 1990 to
2011https://www.youtube.com/watch?v=Yl08jK4ci2g&feature=relmfu
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CapitolaCaliforniaMarch 11,
2011
Reducing Tsunami Hazards
• Warning system in all major oceans
• Local gov’t evacuation routes and procedures
• Education about warning signs– Ground‐shaking in coastal areas
– Unusual disturbance of ocean
– Move to high ground (several hours‐days)
– First wave generally not largest
– https://www.youtube.com/watch?v=qFKgQwou7lsSurfing calving glaciers
• Wave definition, types of waves, orbital waves• Why study waves?• Wave parts, anatomy of a wave• How waves begin, generating force, restoring force• Wave Speed: R=D/T or C=L/T, Celerity• Water motion in waves• Wave base, L/2• Deep water waves, intermediate and shallow water waves• Wind generated waves, H dependent on WfD• Wave types: Sea, Swell and Surf• Waves as they approach the shore: refraction, diffraction and reflection• Canyon divergence and headland convergence• Sea caves, arches and sea stacks• Wave generated currents: longshore and rip• Standing waves: nodes and antinodes, seiches• Catostrophic waves: storm surges and tsunamis• Mega tsunamis: know H, L and P of a typical seismic sea wave!
• Internal waves
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Small Internal Wave in Monterey Bay, 2008
Internal Waves: can have L of 100’s of Ms to 10’s of Kms
H often >50m, T could be from 20 min to a few hrs.
Figure 10_28
Fig. 10.26