In December 2012, Royal Dutch Shell’s arctic drilling rig Kulluk was being towed through the Gulf of Alaska when the weather turned rough. In 18-foot seas, the towline failed, and Kulluk was adrift in a storm. A few days later it ran aground on Sitkalidak Island with 140,000 gallons of diesel in its tanks.
The U.S. Coast Guard and other oil spill responders needed information quickly about the spot where the rig ran aground.
“Is it a sandy beach, or is it a jutting rock cliff that will pulverize the rig when it hits?” asked NOAA Fisheries biologist Mandy Lindeberg by way of example. “Are there salmon streams nearby, or nursery grounds for important fisheries, or other sensitive habitats that need to be protected?”
The Alaska coastline is vast—larger than the combined coastlines of the lower 48 states—and most of it is remote and uninhabited, so answers can be in short supply. And in the middle of winter when there’s little light, flying over for a quick look at the shoreline won’t be much help.
An Archived View of the Exposed Shoreline
But responders were able to do a virtual flyover using an online database called ShoreZone, a sort of Google Street View for the Alaska coastline. Better yet, the view from the virtual flyover is of the shore in summer at extreme low tide, when the full intertidal zone is exposed to daylight.
“At low tide you can see cliffs, rock ramps, stream deltas, all kinds of features that are usually hidden,” said Lindeberg. “These features can stretch a kilometer or more from shore.”
Lindeberg would know—she spends part of each summer photographing the coastline from a helicopter with the doors removed. Why don’t they just use satellite images? Because the shooting schedule has to be precise. They shoot during the 5 days each month with the lowest tides, and only during the 4-hour low tide window on each of those days. Even if you could order up satellite images for those exact times, clouds would probably block the view.
More importantly, the helicopter offers an oblique view of the landscape, revealing surface features in three-dimensional relief that is absent in straight-down satellite images. “We have some very complex shorelines,” Lindeberg said. “Small island groups that you have to circle around, rock reefs, inlets, deltas. We can’t get the detail and scale we need for habitat mapping unless we’re flying tight around those features.”
An Idea Whose Time has Come
The idea for ShoreZone arose in the aftermath of the Exxon Valdez oil spill. To assess the damage from the spill, biologists and others needed to know how much eelgrass there was in Prince William Sound. Eelgrass is important habitat for juvenile fishes, including many commercially valuable species. But how much exactly was there? No one knew.
Today, this type of habitat information is readily available, and not just for Prince William Sound but also for the 80%-and-counting of the Alaska coastline that’s already in ShoreZone. In addition to viewing and downloading photos and video, users can search the database for detailed habitat information and download GIS-compatible digital maps of the biophysical environment.
But most users just download the images, which are themselves full of useful data. Colorful banding patterns that echo out from the shoreline delineate microhabitats in the intertidal zone. Scarring on rocky outcrops shows where winter ice scours the shoreline. And as the climate warms, great diamond-shaped hunks of permafrost can be seen falling into the ocean—the crumbling edge of a coastline in retreat.
The images and data in ShoreZone are used in advance planning for oil spills, by rescuers responding to vessels in distress, and by scientists selecting field sites. NOAA Fisheries and other agencies use ShoreZone to identify important fish habitats, review applications for industrial permits, and monitor the spread of invasive species. And Alaska Native communities use the images to assess the risks posed by eroding shorelines and rising sea levels. As the images make plain, many of those communities will soon have to move.
Finally, the images are beautiful examples of scientific photography—richly detailed visual records of life in the transition zone between land and sea. The Alaska coastline is one of the most bountiful zones on the planet, rich both in life and in mineral and energy resources. It’s also among the most vulnerable in the face of rising seas and increasing industrial development. The images in ShoreZone help professionals manage this great resource, but in their colors, contours, and textures, these beautiful images can help us all appreciate what is at stake in this stretch of a fast-changing world.
Grewingk Glacier River, Kachemak Bay, Cook Inlet: June 24, 2009 Rivers emanating from retreating glaciers carry large volumes of sediment, producing braided river patterns with multiple channels. Braided channels are variable and dynamic. Storm-driven waves erode them. Surging and retreating glaciers then deposit sediments, building them up. During periods of relative stability, opportunistic animals such as the blue mussel (Mytilus trossulus) and marine algae such as the rockweed (Fucus distichus) may colonize the beach face, creating the beautiful colored patterns seen here. Photo: Alaska ShoreZone.
Point Nowell, Knitght Island Passage, Prince William Sound: July 3, 2004 The rock forming these mainland sea cliffs are of the Valdez Group and are composed of tightly folded and metamorphosed marine greywacke and dark gray slate with granite intrusions. The Valdez Group is probably tens of thousands of feet thick and underlies much of the adjacent Chugach and Kenai Mountains. This formation includes the oldest bedded rocks exposed in the Prince William Sound region and is resistant to weathering, which is why it forms most of the steep cliffs and pinnacles in the region. The relatively uniform slope of this sea cliff allows for well-defined vertical zonation of intertidal organisms with the black lichen (Verrucaria maura) in the supratidal, the brown rockweed (Fucus distichus) in the high zone, and a new set of barnacle recruits in the mid zone. A small section of the low zone is visible near the waterline where larger adult barnacles (Semibalanus cariosus) dominate the rock surface. Photo: Alaska ShoreZone.
Prince of Wales Passage, Prince William Sound July 1, 2004 Sea cliffs are a common feature of an eroding coastline. Igneous rocks, such as columnar basalts, are particularly strong and resistant to erosion. In the relatively wave protected environment of Prince William Sound, the cliffs erode primarily by thermal expansion of freezing groundwater seepage and rain water. The broken rock particles tumble into the sea and accumulate as talus at the base of the sea cliff. Ocean waves and currents act only to remove the finer particles from the debris pile. The vertical structure of the columnar basalt is emphasized in this image by intertidal plants. The upper extent of marine zonation on rocky shores in Prince William Sound is typically indicated by a horizontal band of black lichen Verrucaria maura occupying the portion of shore above the highest tide level and wetted only by sea spray. Photo: Alaska ShoreZone.
Tignagvik Point, Kamishak Bay, Cook Inlet June 25, 2009 Waves erode coastal rocks and often create shore platforms like this one. These platforms become colonized by marine plants and animals and support prolific algal growth. Winter ice floes carried by Cook Inlet currents scour away all but the most persistent plants and animals from the rock, often leaving a bare surface for new recruitment of plant spores and animal larvae the following spring. Photo: Alaska ShoreZone.
Mills Bay, Kasaan Bay, Prince of Wales Island, Southeast Alaska July 13, 2007 When a large rock or island is near the shore and the space in between is filled with shallow water, sediments can accumulate if the in-between zone is protected from wave attack. Eventually, a spit forms, linking the mainland to the offshore island. This type of spit is called a Tombolo. You can get a sense for the underlying sediments based on the colors of the vegetation. Rust-colored Rockweed (Fucus distichus), a perennial, grows on stable sediments, while the ephemeral ulvoid seaweeds, which are green, grow on less stable sediments. Photo: Alaska ShoreZone.
Cape Magdalena, Dall island, Southeast Alaska July 28, 2007 Dall Island contains deposits of marble, some of which have been commercially mined starting in the early 20th century. The marble stratum shown here, on the West coast of Dall Island, is vertically dipping—that is, it lies straight up and down. This exposes the relatively soft marble to weathering, and it erodes faster than the harder surrounding rock. Layers of shale and slate are interspersed with layers of marble, causing the alternating light and dark bands. Photo: Alaska ShoreZone.
Tracy Arm, Southeast Alaska Mainland August 4, 2008 Areas recently exposed by retreating glaciers can be harsh environments because the glacier-fed water is low in salinity and high in sediment. Species diversity in such places is very low—mostly tolerant, opportunistic animals such as barnacles and colonizing annuals such as the green ulvoid group of macroalgae. Species that do survive these conditions must also tolerate ice scour—below the thin line of black lichen a bare band shows where ice has scoured the rock clean. Higher up, above the tidal zone, the steep slope and lack of soil makes for a marginal terrestrial habitat. Nitrogen-fixing pants will first colonize the cracks and depressions where freshwater runoff deposits soil. Photo: Alaska ShoreZone.
Brownson Island, Ernest Sound, Southeast Alaska May 06, 2008 A tidal race is a rapid formed by fast-moving tidal currents rushing through a constriction. Ernest Sound in Southeast Alaska has a tidal range of up to 7 meters, which forces great volumes of seawater through the many surrounding inlets and embayments. As the tide rushes out, water surges through these narrows in turbulent rapids and whirlpools. Current speeds here can exceed 16 knots. These areas of high currents often have dense concentrations of filter feeding organisms like mussels and anemones. Photo: Alaska ShoreZone.
East Bight, Nagai Island, Shumagin Islands, The Aleutians May 16, 2011 Regularly-spaced beach cusps are formed by wave action that deposits coarser sediments at the point of the cusp and finer sediments behind. The alongshore spacing is related to wave height and can range from less than a meter to tens of meters. Once formed, beach cusps can be self-sustaining if the prevailing wave pattern remains stable. Photo: Alaska ShoreZone.
Oruktalik Entrance, near Tapkaurak Point, Beaufort Sea August 1, 2012 An inlet cuts a barrier island, allowing water exchange between the Beaufort Sea (upper half of image) and Oruktalik Lagoon. The fingers at the tip of the barrier island are called spits and are formed by waves that travel parallel to the island. Each spit likely represents a pulse of sediment deposited during a storm. Photo: Alaska ShoreZone.
Mary Sachs Entrance, near Prudhoe Bay, Beaufort Sea August 4, 2012 The complex of spits on this barrier island extend like fingers into the Beaufort Sea. Ice floes on the horizon are a reminder that for about nine months of the year, the Beaufort Sea is frozen. Many of the Beaufort barrier islands are migrating landward at rates of 20 meters per year or more, moved by storm surges when waves carry large volumes of sediment. This process is an example of what geologists call “episodic uniformitarianism,” in which the landscape is shaped by infrequent, high-energy events. Photo: Alaska ShoreZone.
McClure Islands August 4, 2012 Blocks of ice are stranded on the inside of this barrier island, while the pack ice is visible on the horizon. This barrier island persists as storms and pack ice continue to deposite logs and sediment on its shores. Photo: Alaska ShoreZone.
Thaw Lake, Prudhoe Bay August 5, 2012 An oil pipeline follows the shoreline of an encroaching lake (lower left) in this oil-rich province not far from the coast of the Beaufort sea (visible in the far background). The low tundra is gradually becoming submerged as the permafrost melts and subsides. At some point, this pipeline may need to move. Photo: Alaska ShoreZone.
Kivalina, on the edge of the Chukchi Sea Humans have been a part of the Alaskan Arctic coastline for thousands of years. In recent times, their villages have consolidated and include permanent infrastrucutre such as roads, runways, and power generating stations. Many of these communities are just a few meters above sea level and are vulnerable to storm surges and rising sea levels. As this image makes clear, Kivalina has no place to go as shorelines are eroding on both the seaward and lagoon side of the barrier spit on which the village is built. Photo: Alaska ShoreZone.
Between Fish Creek and Nechelik Channel, Harrison Bay August 6, 2012 A landscape disappears as tundra slips below sea level. As tundra thaws, it subsides, resulting in a characteristic polygon fracture pattern. The sea invades along these fractures and floods the sunken centers of the polygons. Logs stranded on the rims of the polygons (white in color) show that this entire area is submerged during storm surges. Very small changes in sea level or water level will inundate this low tundra and contribute to further thaw subsidence. Photo: Alaska ShoreZone.
South of Cape Halkett, Harrison Bay August 6, 2012 A tundra surface is under duress as ice wedges thaw along fracture lines and water accumulates in small thaw lakes. A drained thaw lake (foreground) is showing advanced stages of thaw subsidence – almost every fracture is filled with standing water and more than 50% of the tundra is covered in thaw lakes. Photo: Alaska ShoreZone.