Weekly Ocean News

DATASTREME OCEAN SPRING BREAK WEEK: 4-8 March 2013

This is Break Week for the Spring 2013 offering of the DataStreme Ocean course. This Weekly Ocean News contains new information items and historical data, but the Concept of the Week is repeated from Week 6.

For Your Information

Becoming AWARE -- NOAA's National Weather Service and its partner, the Federal Emergency Management Agency (FEMA) are currently observing "National Severe Weather Preparedness Week" that will run through this coming Saturday (9 March). The theme for this year's National Severe Weather Preparedness Week is "Be a Force of Nature." The NOAA "Weather-Ready Nation" website (http://www.nws.noaa.gov/com/weatherreadynation/force.html), contains links that allow the public to "Be a Force of Nature" in their communities through Tweet, a blog post, or a presentation.
Participate in third campaign of Worldwide GLOBE at Night 2013 -- The third in a series of GLOBE at Night citizen-science campaigns for 2013 began Sunday (3 March begin next Thursday (31 January) and continue into the following week, running through 9 February. GLOBE at Night is a worldwide, hands-on science and education program designed to encourage citizen-scientists worldwide to record the brightness of their night sky by matching the appearance of a constellation (Orion or Leo in the northern hemisphere, and Orion and Crux in the southern hemisphere) with seven star charts of progressively fainter stars. In addition to this campaign and the two previously held in early January and early February, the two additional GLOBE at Night campaigns will be in 2013: 31 March-9 April and 29 April-8 May. Check the GLOBE at Night website for additional information on this week's activities plus a Teacher Information Page and activity packet.
Biomixing in ocean motion -- If you would like information on recent findings that indicate marine organisms contribute to motion in the ocean, please read this week's Supplemental Information…In Greater Depth.

Ocean in the News

Eye on the tropics --- As meteorological summer concluded in the Southern Hemisphere last week, tropical cyclone activity was limited to the South Indian Ocean basin. Tropical Storm Rusty, which had formed at the start of last week over the waters north of Australia at the start of the week, intensified as it traveled south toward the Australian coast. , Rusty became a category 2 tropical cyclone on the Saffir-Simpson Scale within 18 hours before making landfall late Wednesday afternoon (local time) along Western Australia's Pilbara coast to the east-northeast of Port Hedland. Consult the NASA Hurricane Page for satellite imagery and additional information on Tropical Cyclone Rusty.
Early last week, a tropical storm that was identified as Tropical Cyclone 18S formed over the waters of the South Indian Ocean to the southeast of Australia's Cocos (Keeling) Islands, approximately halfway between Australia and Sri Lanka. This cyclone remained a relatively weak tropical storm as it traveled toward the south-southeast before dissipating by midweek. Additional information along with satellite imagery on Tropical Storm 18S can be found on the NASA Hurricane Page.
Plans made for new Arctic nautical charts -- Officials with NOAA's Office of Coast Survey recently issued an updated plan designed to improve the inadequate coverage provided by current nautical charts across Arctic areas. These updates are particularly needed as the Arctic areas are currently experiencing increased traffic by vessels as sea ice diminishes. As many as 14 new charts are planned that would complement existing chart coverage. [NOAA News]
Research funded to investigate where Caribbean fish gather to spawn -- NOAA is helping fund scientists at the University of Puerto Rico work with Caribbean resource managers to conduct research that would help identify areas where Caribbean fish such as groupers congregate and spawn in an effort to protect these fish from overfishing and allow for the rebuilding of the depleted fisheries population. [NOAA News]
International law enforcement partnerships address worldwide fisheries crime -- The Director of NOAA's Office of Law Enforcement has recently announced that a new partnership effort called Project SCALE has been launched with the international police organization INTERPOL to detect, combat and suppress fisheries crime worldwide, which is estimated to cost the global economy as much as $23 billion annually. Project SCALE is also designed to improve the exchange of fisheries enforcement information and intelligence between participating countries. [NOAA's National Marine Fisheries Service]
Marsh habitat restoration in western Washington serves as a case study -- The Fisher Slough Project, a marsh restoration project involving NOAA's National Marine Fisheries Service and the Nature Conservancy, is highlighted as an example of habitat restoration. This project in western Washington near the community of Mt. Vernon involved the improvement of 14 miles of stream for fish passage and the restoration of 50 acres of freshwater marsh habitat near Puget Sound. [NOAA Habitat Conservation]
New appointments to the Marine Fisheries Advisory Committee announced -- During the last week, the Assistant Administrator for Fisheries appointed nine new members to the agency's Recreational Fisheries Working Group that provides advice to the Marine Fisheries Advisory Committee. These appointees represent marine recreational fishing interest from across the nation, including US territories. [NOAA's National Marine Fisheries Service]
Post-Sandy recovery efforts by National Ocean Service updated -- Partnership efforts that the NOAA's National Ocean Service (NOS) and other federal, state, and local agencies have delivered to help communities along the Middle Atlantic recover from last October's Hurricane Sandy are outlined. Because of operational and scientific expertise, NOS staff was able to assist their partners with a suite of resources and tools to aid recovery. [NOAA National Ocean Service]
New Aquarius satellite detects shifts in ocean salinity -- A team of scientists have created an animated sequence of images obtained from NASA's Aquarius instrument onboard NASA/Space Agency of Argentina's Aquarius satellite that shows seasonal changes in the salinity (or salt content) of the surface layers of the world's oceans over this first full year that the instrument has been operative after its launch in 2011. This global view of the salinity variations are needed for climate studies. [NASA's Earth Science News Team]
An All-Hazards Monitor -- This Web portal provides the user information from NOAA on current environmental events that may pose as hazards such as tropical weather, drought, floods, marine weather, tsunamis, rip currents, Harmful Algal Blooms (HABs) and coral bleaching. [NOAAWatch]
Global and US Hazards/Climate Extremes -- A review and analysis of the global impacts of various weather-related events, to include drought, floods and storms during the current month. [NCDC]
Earthweek -- Diary of the Planet [earthweek.com] Requires Adobe Acrobat Reader.

This Concept of the Week is repeated from Week 6.

Concept of the Week: Abyssal Storms

Until recently, ocean scientists thought of the deep ocean abyss as a dark and cold, but serene place where small particles rained gently onto the ocean floor. However, instruments lowered to the sea floor to measure ocean motion or currents and resulting mobilization of bottom sediments detected a much more active environment. Scientists found that bottom currents and abyssal storms occasionally scour the ocean bottom, generating moving clouds of suspended sediment. A surface current of 5 knots (250 cm/sec) is considered relatively strong. A bottom current of 1 knot (50 cm/sec) is ripping. Although this may be called an abyssal storm, the water motion pales by comparison to wind speeds in atmospheric storms.

Abyssal currents and storms apparently derive their energy from surface ocean currents. Wind-driven surface ocean currents flow about the margins of the ocean basins as gyres centered near 30 degrees latitude. (Refer to Figure 6.6, page 152, in your textbook.) Viewed from above, these subtropical gyres rotate clockwise in the Northern Hemisphere and counterclockwise in the Southern Hemisphere. For reasons given in Chapter 6 of your textbook and this week's Supplemental Information, surface currents flow faster, are narrower, and extend to greater depths on the western arm of the gyres. These are known as western boundary currents and include, for example, the Gulf Stream of the North Atlantic basin. Abyssal currents are also most vigorous on the western side of the ocean basins, moving along the base of the continental rise, which is on the order of several kilometers deep.

Abyssal storms may be linked to or may actually be eddies (rings) that occasionally break off from the main current of the Gulf Stream (and other western boundary currents). During an abyssal storm, the eddy or ring may actually reach to the bottom of the ocean where the velocity of a bottom current increases ten-fold to about 1.5 km (1 mi) per hr. While that is an unimpressive wind speed, water is much denser than air so that its erosive and sediment-transport capacity is significant even at 1.5 km per hr. At this higher speed, the suspended sediment load in the bottom current increases by a factor of ten. Abyssal storms scour the sea floor leaving behind long furrows in the sediment. After a few days to a few weeks, the current weakens or the eddy (ring) is reabsorbed into the main surface circulation and the suspended load settles to the ocean floor. In this way, abyssal storms can transport tons of sediment long distances, disrupting the orderly sequence of layers of deep-sea sediments. Scientists must take this disruption into account when interpreting the environmental significance of deep-sea sediment cores.

Concept of the Week: Questions

In the subtropical ocean gyres, boundary currents flow faster on the [(western)(eastern)] side of an ocean basin.
Currents in an abyssal storm erode, transport, and redeposit sediments that have accumulated on the [(continental shelf)(deep ocean bottom)].

Historical Events

5 March 1914...The Spanish ship the Principe de Asturias enroute from Barcelona to Buenos Aires sank with the loss of 445 of the 588 passengers and crew members when it struck the jagged reefs along the Brazilian coast at Ponta Boi in dense fog.
5-6 March 1962...The Great Atlantic Coast Storm of 1962 caused more than $200 million in property damage from Florida to New England. Winds along the Middle Atlantic Coast reached 70 mph raising 40-ft waves, and 42 inches of snow fell at Big Meadows, in the mountains of Virginia--a state record. The storm caused greater alteration of the coastline from Cape Hatteras, NC to Long Island than any previous storm, including hurricanes. A new inlet was cut through Hatteras Island and more than 10 miles of Outer Banks barrier dunes were obliterated. The Virginia shoreline was rearranged by historic tidal flooding caused by the combination of the long stretch of strong onshore winds and the spring tides. A 3-mile long boardwalk in Ocean City, MD was wiped out. (David Ludlum) (Intellicast)
6 March 1521...The Portuguese explorer Ferdinand Magellan reached Guam in his around the world voyage. (Wikipedia)
6 March 1987...The British ferry Herald of Free Enterprise capsized in the English Channel off the coast of Belgium with the loss of 189 people.
7 March 1778...Captain James Cook first sighted the Oregon coast, at Yaquina Bay near present day Newport.
7 March 1932...A severe coastal storm set barometric pressure records from Virginia to New England. Block Island, RI reported a barometric pressure reading of 955.0 millibars (28.20 inches of mercury). (David Ludlum)
9 March 1454...Amerigo Vespucci, the Italian navigator, was born in Florence, Italy. The North and South American continents were named in his honor by Matthias Ringmann, a German mapmaker.
9 March 1995...The Canadian Navy arrested a Spanish trawler for illegally fishing off Newfoundland.
10 March 1496...Christopher Columbus concluded his second visit to the Western Hemisphere when he left Hispaniola for Spain. (Wikipedia)
10 March 1849...Abraham Lincoln applied for a patent for a device to lift vessels over shoals by means of inflated cylinders.