Hurricane Hugo, Puerto Rico, the Virgin Islands, and Charleston, South Carolina, September 17-22, 1989 (1994) / Chapter Skim
Currently Skimming:
Coastal Processes
Coastal Processes
Pages 130-154
The Chapter Skim interface presents what we've algorithmically identified as the most significant single chunk of text within every page in the chapter.
Select key terms on the right to highlight them within pages of the chapter.
From page 130... ...
Storm surge is the difference between fairweather and storm water levels, due largely to the combined effects of wind pushing water onshore literally piling the water up against the land and extremely low atmospheric pressures, which actually bulges the ocean upward. These forces combine to force the ocean landward, bringing slightly deeper water to places that have normally shallow water, or bringing water into places that are normally above sea level.
|
From page 131... ...
Probably the best action that can be taken to reduce the risk from storms is to elevate structures and people at risk get them up out of the storm waters. Perhaps the best example of this is the city of 01d San Juan, built at high elevation near the entrance to San Juan Harbor.
|
From page 132... ...
In Puerto Rico, there is so little shelf water to be piled up into a storm surge that surges are inherently lower. The wide South Carolina continental shelf is essentially a broad, shallow "pan" of water that can be forced landward by storms, leading to inherently higher storm surges than in Puerto Rico from the same forcing storm.
|
From page 133... ...
The metropolitan San Juan area and outlying coastal sectors were observed (see Figure 6-2~. From Luquillo to the west, the hurricane-force winds were blowing directly onshore and caused considerable damage from direct-wave attack as well as from surge and sand overwash.
|
From page 134... ...
and the U.S. Virgin Islands observed by the field study team, damage was very similar to those observed on the main island; that is, largely wind damage with water damage (wave and storm surge)
|
From page 135... ...
does not account for waves. Luquillo was the only place other than the San Juan tide gage station where a reliable storm surge was measured.
|
From page 136... ...
rooP' harbor of Culebra, showing ships grounded by storm surge. notice that ships did not float very far inland—testimony to the small penetration of storm surge owing to the steep terrain.
|
From page 137... ...
Reduced penetration of storm surge owing to steep terrain (see also Figures 6-5 and 6-6~. Courtesy: Richard Marshall, 1989.
|
From page 138... ...
Punta Maldonado I I.5 M THICK ] t ~ , ~ ~ Pinones Islo Verde ;>J j San Juan .
|
From page 139... ...
Major overwash occurred at Barbosa Park, just west of Punta las Marias, as well (see Figure 6-2~. Other areas did not experience significant sand overwash.
|
From page 140... ...
Shoreline retreat during the storm, in addition to collapsing walls, exposed tree roots, as shown in Figures 6-13 and 6-14 from Punta las Marias. Shoreline erosion also exhumed infrastructure, as shown in Figure 6-15 at Punta el Medio in Isla Verde.
|
From page 141... ...
Coastal Processes FIGURE 6-11 Destroyed front of Oasis Restaurant in the Condado. FIGURE 6-12 A boulder that had been thrown over a 1-m wall in the Condado.
|
From page 142... ...
~ .. ~ FIGURE 6-13 Shorefront in Punta las Marias, Calle Almendro, showing unearthed tree roots, toppled seawall, and shoreline retreat.
|
From page 143... ...
Coastal Processes FIGURE 6-15 Punta el Medio area in Isla Verde showing unearthed water and waste pipes. FIGURE 6-16 Punta Uvero area showing destruction of revetment and first row structures.
|
From page 144... ...
There was little shoreline damage south of the Roosevelt Roads Naval Station. Some minor overwash on the east coast and removal of sand at the Caribe Playa Sunbeach Resort near Cabo Mala Pascua on the south coast was noted.
|
From page 145... ...
Coastal Processes ... FIGURE 6-18 Barbosa Park shoreline after Hugo.
|
From page 146... ...
Winter storm waves will thus attack an already degraded shoreline. This is called "setting up" the shoreline for FIGURE 6-20 Shorefront of Caribe Playa Sunbeach Resort near Cabo Mala Pascua.
|
From page 147... ...
. Prior to the passage of Hurricane Hugo, personnel from NURC-FDU deployed a S4 current meter, manufactured by InterOcean Systems, Inc., to collect data on the storm passage (Taylor and Trageser, 1990~.
|
From page 148... ...
A variety of shoreline settings have been studied, ranging from the East Coast of the United States to the Yucatan Peninsula after Hurricane Gilbert in 198S, to Puerto Rico and South Carolina after Hurricane Hugo. Observations have been made before and after winter storms as well as hurricanes.
|
From page 149... ...
Modal S4 Current Meter #04911948 tIDGO HEST WALL File : A,ln~Yo.S4B Samples averaged, 1 Mean ' 19.39 17281 Samples 20521 9/17, 22:33:~8 9/18, 84,33 00 FIGURE 6-22b Depth of water overcurrent meter for bursts 17, 18, and 19. Courtesy: Taylor and Trageser, 1990.
|
From page 150... ...
Where dunes, rather than buildings, are present to absorb the impact of waves and storm surge, post-storm beaches are markedly wider. In addition, structures located behind the frontal line of dunes are usually not damaged.
|
From page 151... ...
Rocky shorelines erode slowly and add may elevation, thus protecting structures located on them. No better example exists than the longevity of 01d San Juan, situated high atop the rocky shoreline.
|
From page 152... ...
Such a study would assess the islandwide and community-by-community erosion situation, start a continuous beach-profiling program, make islandwide and communitywide recommendations of shoreline-management alternatives, and begin planning for the sea-level rise. The USGS Marine Geology Office in San Juan, cooperatively with the PRDNR, has an ongoing study of the beaches of the San Juan metropolitan area that has been under way for several years.
|
From page 153... ...
8. Form a "Beach Watchdog" committee, with representatives from the USGS Marine Geology Office, the PRDNR, the Puerto Rico Planning Board, and other public and private groups (i.e., the Tourism Company, Hotel Owners Association, environmental groups, etc.~.
|
From page 154... ...
1990. Directional wave and current measurements during Hurricane Hugo.
|
Key Terms
This material may be derived from roughly machine-read images, and so is provided only to facilitate research.
More
information on Chapter Skim is available.