Thursday, April 24, 2008
The northwest shore of Oahu is famous for its huge winter surf. I remember hearing about the Banzai Pipeline and Waimea Bay when I was a kid, probably on Wide World of Sports on a Saturday afternoon (probably not the same Saturday afternoon I saw Endless Summer). It's pretty neat to see the real places, even if today's waves are pretty tame (they're the result of easterly trade winds wrapping around the north end of the island - whereas the winter surf is generated by swells thrown off by North Pacific storms). The waves may not have been huge, but the shore break looked brutal enough in a couple of places I worried a little bit about some of the kids. And I know those guys offshore are only a few feet of water way from a jagged bottom. Last day - time to go back to North America.
This is a wonderful small pocket beach near the northern tip of Oahu. It is bracketed by two narrow tongues of old coral that project seaward and is sheltered from the North Pacific swell by the modern reef offshore. The beach lies in the afternoon shadow of a large resort hotel perched on one of the points, but like all Hawaii beaches, it remains publicly accessible.
The old coral is reportedly 125,000 years old, dating to the last high stand of sea level, several meters above what it is today ... about what it will be in 200 years if Greenland continues to melt at the rate it is today?
In 1946, an earthquake in the Aleutians sent a tsunami southward - six hours later Hilo, on the big island, was devastated. Here near Kahuku Point, it washed inland as much as a mile and may have been 20-30' deep. This hotel, built in the 1970s, was designed with tsunamis in mind, although we probably know far more about them now than we did then. The hotel might survive, but the restaurants and the condos might not and the cars in the parking lots would probably wind up draped from trees around the golf courses.
Hanamau is a large pocket beach in a breached volcanic crater. Somehow it manages to live up to its status as a natural preserve, while also preserving the ability of millions of people every year to visit (mainly to snorkel). That the reef actually manages to survive with all that human traffic is remarkable. They do require visitors to attend a short "do not touch" video before heading down to the beach - an obligation many were trying desperately to bypass.
Kuhio is one of the several beaches on the greater Waikiki strand - it is immediately east of central Waikiki. It lies on a protected lagoon formed by a breakwater and several groins. The eastern end is formed by the Kapahulu Groin - which pretends to be a pier, but isn't open underneath.
Most of my entries are about little gravel beaches on Puget Sound without much of a reputation -- so it's fun to add a truly famous one.
Waikiki isn't quite the uniform beach strip I had imagined. It's a strange mix of beach, groins, breakwaters, and seawalls. It's actually a series of beaches, each with its own geologic character (and probably social character, too). Gray's Beach, from the Sheraton west to Fort DeRussy, isn't much of a beach at all these days - just an undermined seawall.
Waikiki was originally a narrow barrier separating a large marshy area from the ocean, but clever humans drained the swamp, raised the land, and added sand to the beach, converting a local beach into one of the most famous coastal resorts in the world. And creating a lot of land on which to build big hotels.
Sand on Waikiki (there's not really that much of it - the nearshore is mainly a broad reef, with just a fringe of sand at the shore) has been replenished from offshore, from beaches elsewhere on the islands, and even from California. In the 1920s, the developers of Manhattan Beach (Los Angeles) found their large dunes inconvenient, so they barged them to Honolulu (really, at least it says so on the internet,. It was done by a construction firm run by the Kuhn Brothers). The beach sand is gradually being lost offshore, filling in holes and channels in the reef, and moves are afoot to pump some of it back onshore. I wonder how much sand is lost each year by tourists tracking it back to their hotels.
Tuesday, April 22, 2008
Not really an island at all, this peninsula was created in the 1960s. Seawalls protect its flanks, while its southern tip contains a beach and a lagoon protected by a segmented breakwater that allows circulation but few significant waves. The seawall on the western side is a fitted rock revetment with a gorgeous recurved seawall perched on top.
Ala Moana appears to be to locals what Waikiki is to tourists - or so it seemed this pleasant Saturday afternoon. This is a wide sandy beach, backed by a seawall and road and a large park. Like Waikiki, its configuration is artificial, shaped by dredging projects and land fill, and the beach consists of sediment has been shipped in from elsewhere.
Sunday, April 20, 2008
The southwest corner of Kauai consists of a broad foreland built out in front of the eroding flank of the 5 million year old shield volcano. Seacliffs formed during the last high stand of sea level (4-6 meters higher, 125,000 years ago) have been long stranded. However, at the northwestern end of the beach, the wide plain squeezes away to nothing and gives rise to the active seacliffs of the Na Pali coast (we're only about 15 miles from Ke'e Beach at the northeast end, where we were yesterday). The contrast between the broad sand beach and dunes and the high basalt cliffs is spectacular (more comments and pictures at hshipman). It is no wonder that this is an area with high religious significance - it was the jumping off point for the spirits when it was time to move on. Nice choice.
The base of the Na Pali cliffs is marked by a natural riprap revetment of basaltic boulders.
Waimea apparently means "muddy river" and most of the islands have one. Black sand beaches are the result of eroding volcanics where ground up sand-size basalt and dark minerals get concentrated by the waves. They can be found on some of the other islands - I'm told the Big Island may be best. This beach is a bit different and might be better characterized as a brown sand beach. The ingredients may be correct, but the dirt is fresh from the river and the beach is more a muddy brown sand and silt. The river drains the spectacular canyon that lies just a few miles upstream.
The paper and the clothing in the old dump erode from the bluff and decompose or get blown away. The glass bottles and electrical insulators get ground up into sand and redeposited in the small pocket beach below the fuel tanks (thus the name Glass Beach). The metal metamorphoses in the saltwater, leaving a rocky headland of engine blocks and wheel hubs.
Maybe not most people's image of the beaches of Paradise!
This stretch of cliff and beach lies east of the Grand Hyatt in Poipu, on the southern shore of the Ha'upu range. A dirt road leads past the golf course and across a couple of miles of old plantation before arriving at the middle of three pocket beaches. Kamala Point, on the west, consists of low dunes and a sandy beach, and may owe its existence to the presence of the reef and to a lag of basaltic boulders. Pao'a Point to the east, on the other hand, is composed of cliffs of lithified sand dunes, reportedly formed when sea level was lower. An easy and very pretty walk leads to Ha'ula Beach, which is the easternmost of the pocket beaches. Waves from today's southeastern swell were crashing against the cliffs in the distance.
Thursday, April 10, 2008
Ke'e is the beach at the end of the road. Where the Na Pali Coast begins. The reef lies just offshore, forming a small lagoon, great for snorkeling neophytes. East of here, pocket beaches and rocky headlands alternate across a the front of a broad coastal terrace. West of here, beaches are limited to tiny pockets at the base of valleys in the spectacular line of cliffs. I'll save the boat cruise and the helicopter flight for a trip with more time and with the family along. Maybe the hike, too.
Besides colorful fish and coral, this beach had plenty of chickens. That's a new one for me.
The weather started overcast, but the sun broke through noon, just before it started pouring. I think I was lucky to get back to Hanalei for lunch - the streams were already rising and rocks were collapsing on the road.
This beach on Kauai faces north, towards the Aleutian Islands, which lie just five or six hours away, by tsunami. Very calm this morning - with fairly small waves breaking on the reef a few hundred yards offshore. Must be impressive in the winter when big waves march south across the Pacific, tripping on Hawaii as they pass.
In a twisted way, this place resembles Puget Sound. Steep beach face. Gravel tossed high on the beach by storms - composed of ground up chunks of the coral. Scattered cobbles and boulders - of 5 million year old basalt. A forested backshore with trees hanging out across the beach and large wood on the beach - tropical stuff that I don't recognize. Expensive homes behind the beach - except that this beach isn't marked with No Trespassing signs.