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1

Pathfinders.  

ERIC Educational Resources Information Center

Discusses the use of pathfinders, i.e., bibliographic tools designed to assist patrons in locating published information in specific fields by themselves. Use of pathfinders as teaching tools and special suggestions for their development by public libraries are noted. A pathfinder on personal financial management is included. (EJS)

Warner, Alice Sizer

1983-01-01

2

Pathfinder-Plus on flight in Hawaii  

NASA Technical Reports Server (NTRS)

Pathfinder-Plus on a flight over Hawaii in 1998. Pathfinder was a remotely controlled, solar-powered flying wing, designed and built as a proof-of-concept vehicle for a much larger aircraft capable of flying at extremely high altitudes for weeks at a time. It was built by AeroVironment, Inc., a California company that developed the human-powered Gossamer Condor and Gossamer Albatross lightweight aircraft during the 1970s, and later made the solar-electric powered Gossamer Penguin and Solar Challenger. The basic configuration and concepts for Pathfinder were first realized with the HALSOL (High Altitude Solar) aircraft, built in 1983 by AeroVironment and the Lawrence Livermore Laboratory. Pathfinder was constructed of advanced composites, plastics, and foam, and despite a wingspan of nearly 100 feet, it weighed only about 600 pounds. Pathfinder was one of several unpiloted prototypes under study by NASA's ERAST (Environmental Research Aircraft and Sensor Technology) program, a NASA-industry alliance which is helping develop advanced technologies that will enable aircraft to study the earth's environment during extremely long flights at altitudes in excess of 100,000 feet. (See project description below for Pathfinder's conversion to Pathfinder Plus.) In 1998, the Pathfinder solar-powered flying wing (see its photographs and project description) was modified into the longer-winged Pathfinder Plus configuration and on Aug. 6, 1998, Pathfinder Plus set an altitude record (for propeller-driven aircraft) of approximately 80,285 feet at the Pacific Missile Range Facility. The goal of the Pathfinder Plus flights was to validate new solar, aerodynamic, propulsion, and systems technology developed for its successor, the Centurion, which was designed to reach and sustain altitudes in the 100,000-foot range. The Centurion was succeeded by the Helios Prototype with a goal of reaching and sustaining flight at an altitude of 100,000 feet and flying non-stop for at least 4 days above 50,000 feet. Major activities of Pathfinder Plus' Hawaiian flights included detection of forest nutrient status, forest regrowth after damage caused by Hurricane Iniki in 1992, sediment/algal concentrations in coastal waters, and assessment of coral reef health. Pathfinder science activities were coordinated by NASA's Ames Research Center, Mountain View, California, and included researchers from the University of Hawaii and the University of California. Pathfinder is part of NASA's Environmental Research Aircraft and Sensor Technology (ERAST) program managed by NASA's Dryden Flight Research Center, Edwards, California. Pathfinder and Pathfinder Plus were designed, built, and operated by AeroVironment, Inc., Monrovia, California. Pathfinder had a 98.4-foot wing span and weighed 560 pounds. Pathfinder Plus has a 121-foot wing span and weighs about 700 pounds. Pathfinder was powered by six electric motors while Pathfinder Plus has eight. Pathfinder's solar arrays produced approximately 8,000 watts of power while Pathfinder Plus' solar arrays produce about 12,500 watts of power. Both Pathfinder aircraft were built primarily of composites, plastic, and foam.

1998-01-01

3

Pathfinder-Plus on flight over Hawaii  

NASA Technical Reports Server (NTRS)

Pathfinder-Plus on flight over Hawaii. Pathfinder was a remotely controlled, solar-powered flying wing, designed and built as a proof-of-concept vehicle for a much larger aircraft capable of flying at extremely high altitudes for weeks at a time. It was built by AeroVironment, Inc., a California company that developed the human-powered Gossamer Condor and Gossamer Albatross lightweight aircraft during the 1970s, and later made the solar-electric powered Gossamer Penguin and Solar Challenger. The basic configuration and concepts for Pathfinder were first realized with the HALSOL (High Altitude Solar) aircraft, built in 1983 by AeroVironment and the Lawrence Livermore Laboratory. Pathfinder was constructed of advanced composites, plastics, and foam, and despite a wingspan of nearly 100 feet, it weighed only about 600 pounds. Pathfinder was one of several unpiloted prototypes under study by NASA's ERAST (Environmental Research Aircraft and Sensor Technology) program, a NASA-industry alliance which is helping develop advanced technologies that will enable aircraft to study the earth's environment during extremely long flights at altitudes in excess of 100,000 feet. (See project description below for Pathfinder's conversion to Pathfinder Plus.) In 1998, the Pathfinder solar-powered flying wing (see its photographs and project description) was modified into the longer-winged Pathfinder Plus configuration and on Aug. 6, 1998, Pathfinder Plus set an altitude record (for propeller-driven aircraft) of approximately 80,285 feet at the Pacific Missile Range Facility. The goal of the Pathfinder Plus flights was to validate new solar, aerodynamic, propulsion, and systems technology developed for its successor, the Centurion, which was designed to reach and sustain altitudes in the 100,000-foot range. The Centurion was succeeded by the Helios Prototype with a goal of reaching and sustaining flight at an altitude of 100,000 feet and flying non-stop for at least 4 days above 50,000 feet. Major activities of Pathfinder Plus' Hawaiian flights included detection of forest nutrient status, forest regrowth after damage caused by Hurricane Iniki in 1992, sediment/algal concentrations in coastal waters, and assessment of coral reef health. Pathfinder science activities were coordinated by NASA's Ames Research Center, Mountain View, California, and included researchers from the University of Hawaii and the University of California. Pathfinder is part of NASA's Environmental Research Aircraft and Sensor Technology (ERAST) program managed by NASA's Dryden Flight Research Center, Edwards, California. Pathfinder and Pathfinder Plus were designed, built, and operated by AeroVironment, Inc., Monrovia, California. Pathfinder had a 98.4-foot wing span and weighed 560 pounds. Pathfinder Plus has a 121-foot wing span and weighs about 700 pounds. Pathfinder was powered by six electric motors while Pathfinder Plus has eight. Pathfinder's solar arrays produced approximately 8,000 watts of power while Pathfinder Plus' solar arrays produce about 12,500 watts of power. Both Pathfinder aircraft were built primarily of composites, plastic, and foam.

1998-01-01

4

Pathfinder-Plus on flight over Hawaii  

NASA Technical Reports Server (NTRS)

Pathfinder-Plus flying over the Hawaiian Islands in 1998 with Ni'ihau Island in the background. Pathfinder was a remotely controlled, solar-powered flying wing, designed and built as a proof-of-concept vehicle for a much larger aircraft capable of flying at extremely high altitudes for weeks at a time. It was built by AeroVironment, Inc., a California company that developed the human-powered Gossamer Condor and Gossamer Albatross lightweight aircraft during the 1970s, and later made the solar-electric powered Gossamer Penguin and Solar Challenger. The basic configuration and concepts for Pathfinder were first realized with the HALSOL (High Altitude Solar) aircraft, built in 1983 by AeroVironment and the Lawrence Livermore Laboratory. Pathfinder was constructed of advanced composites, plastics, and foam, and despite a wingspan of nearly 100 feet, it weighed only about 600 pounds. Pathfinder was one of several unpiloted prototypes under study by NASA's ERAST (Environmental Research Aircraft and Sensor Technology) program, a NASA-industry alliance which is helping develop advanced technologies that will enable aircraft to study the earth's environment during extremely long flights at altitudes in excess of 100,000 feet. (See project description below for Pathfinder's conversion to Pathfinder Plus.) In 1998, the Pathfinder solar-powered flying wing (see its photographs and project description) was modified into the longer-winged Pathfinder Plus configuration and on Aug. 6, 1998, Pathfinder Plus set an altitude record (for propeller-driven aircraft) of approximately 80,285 feet at the Pacific Missile Range Facility. The goal of the Pathfinder Plus flights was to validate new solar, aerodynamic, propulsion, and systems technology developed for its successor, the Centurion, which was designed to reach and sustain altitudes in the 100,000-foot range. The Centurion was succeeded by the Helios Prototype with a goal of reaching and sustaining flight at an altitude of 100,000 feet and flying non-stop for at least 4 days above 50,000 feet. Major activities of Pathfinder Plus' Hawaiian flights included detection of forest nutrient status, forest regrowth after damage caused by Hurricane Iniki in 1992, sediment/algal concentrations in coastal waters, and assessment of coral reef health. Pathfinder science activities were coordinated by NASA's Ames Research Center, Mountain View, California, and included researchers from the University of Hawaii and the University of California. Pathfinder is part of NASA's Environmental Research Aircraft and Sensor Technology (ERAST) program managed by NASA's Dryden Flight Research Center, Edwards, California. Pathfinder and Pathfinder Plus were designed, built, and operated by AeroVironment, Inc., Monrovia, California. Pathfinder had a 98.4-foot wing span and weighed 560 pounds. Pathfinder Plus has a 121-foot wing span and weighs about 700 pounds. Pathfinder was powered by six electric motors while Pathfinder Plus has eight. Pathfinder's solar arrays produced approximately 8,000 watts of power while Pathfinder Plus' solar arrays produce about 12,500 watts of power. Both Pathfinder aircraft were built primarily of composites, plastic, and foam.

1998-01-01

5

Research Spotlight: New method to assess coral reef health  

NASA Astrophysics Data System (ADS)

Coral reefs around the world are becoming stressed due to rising temperatures, ocean acidification, overfishing, and other factors. Measuring community level rates of photosynthesis, respiration, and biogenic calcification is essential to assessing the health of coral reef ecosystems because the balance between these processes determines the potential for reef growth and the export of carbon. Measurements of biological productivity have typically been made by tracing changes in dissolved oxygen in seawater as it passes over a reef. However, this is a labor-intensive and difficult method, requiring repeated measurements. (Geophysical Research Letters, doi:10.1029/2010GL046179, 2011)

Tretkoff, Ernie

2011-03-01

6

Pathfinder-Plus on a flight in Hawaii  

NASA Technical Reports Server (NTRS)

Pathfinder-Plus on a flight in 1998 over Hawaiian waters. Pathfinder was a remotely controlled, solar-powered flying wing, designed and built as a proof-of-concept vehicle for a much larger aircraft capable of flying at extremely high altitudes for weeks at a time. It was built by AeroVironment, Inc., a California company that developed the human-powered Gossamer Condor and Gossamer Albatross lightweight aircraft during the 1970s, and later made the solar-electric powered Gossamer Penguin and Solar Challenger. The basic configuration and concepts for Pathfinder were first realized with the HALSOL (High Altitude Solar) aircraft, built in 1983 by AeroVironment and the Lawrence Livermore Laboratory. Pathfinder was constructed of advanced composites, plastics, and foam, and despite a wingspan of nearly 100 feet, it weighed only about 600 pounds. Pathfinder was one of several unpiloted prototypes under study by NASA's ERAST (Environmental Research Aircraft and Sensor Technology) program, a NASA-industry alliance which is helping develop advanced technologies that will enable aircraft to study the earth's environment during extremely long flights at altitudes in excess of 100,000 feet. (See project description below for Pathfinder's conversion to Pathfinder Plus.) In 1998, the Pathfinder solar-powered flying wing (see its photographs and project description) was modified into the longer-winged Pathfinder Plus configuration and on Aug. 6, 1998, Pathfinder Plus set an altitude record (for propeller-driven aircraft) of approximately 80,285 feet at the Pacific Missile Range Facility. The goal of the Pathfinder Plus flights was to validate new solar, aerodynamic, propulsion, and systems technology developed for its successor, the Centurion, which was designed to reach and sustain altitudes in the 100,000-foot range. The Centurion was succeeded by the Helios Prototype with a goal of reaching and sustaining flight at an altitude of 100,000 feet and flying non-stop for at least 4 days above 50,000 feet. Major activities of Pathfinder Plus' Hawaiian flights included detection of forest nutrient status, forest regrowth after damage caused by Hurricane Iniki in 1992, sediment/algal concentrations in coastal waters, and assessment of coral reef health. Pathfinder science activities were coordinated by NASA's Ames Research Center, Mountain View, California, and included researchers from the University of Hawaii and the University of California. Pathfinder is part of NASA's Environmental Research Aircraft and Sensor Technology (ERAST) program managed by NASA's Dryden Flight Research Center, Edwards, California. Pathfinder and Pathfinder Plus were designed, built, and operated by AeroVironment, Inc., Monrovia, California. Pathfinder had a 98.4-foot wing span and weighed 560 pounds. Pathfinder Plus has a 121-foot wing span and weighs about 700 pounds. Pathfinder was powered by six electric motors while Pathfinder Plus has eight. Pathfinder's solar arrays produced approximately 8,000 watts of power while Pathfinder Plus' solar arrays produce about 12,500 watts of power. Both Pathfinder aircraft were built primarily of composites, plastic, and foam.

1998-01-01

7

Pathfinder-Plus takes off on flight in Hawaii  

NASA Technical Reports Server (NTRS)

Pathfinder-Plus on a flight over Hawaii in 1998. Pathfinder was a remotely controlled, solar-powered flying wing, designed and built as a proof-of-concept vehicle for a much larger aircraft capable of flying at extremely high altitudes for weeks at a time. It was built by AeroVironment, Inc., a California company that developed the human-powered Gossamer Condor and Gossamer Albatross lightweight aircraft during the 1970s, and later made the solar-electric powered Gossamer Penguin and Solar Challenger. The basic configuration and concepts for Pathfinder were first realized with the HALSOL (High Altitude Solar) aircraft, built in 1983 by AeroVironment and the Lawrence Livermore Laboratory. Pathfinder was constructed of advanced composites, plastics, and foam, and despite a wingspan of nearly 100 feet, it weighed only about 600 pounds. Pathfinder was one of several unpiloted prototypes under study by NASA's ERAST (Environmental Research Aircraft and Sensor Technology) program, a NASA-industry alliance which is helping develop advanced technologies that will enable aircraft to study the earth's environment during extremely long flights at altitudes in excess of 100,000 feet. (See project description below for Pathfinder's conversion to Pathfinder Plus.) In 1998, the Pathfinder solar-powered flying wing (see its photographs and project description) was modified into the longer-winged Pathfinder Plus configuration and on Aug. 6, 1998, Pathfinder Plus set an altitude record (for propeller-driven aircraft) of approximately 80,285 feet at the Pacific Missile Range Facility. The goal of the Pathfinder Plus flights was to validate new solar, aerodynamic, propulsion, and systems technology developed for its successor, the Centurion, which was designed to reach and sustain altitudes in the 100,000-foot range. The Centurion was succeeded by the Helios Prototype with a goal of reaching and sustaining flight at an altitude of 100,000 feet and flying non-stop for at least 4 days above 50,000 feet. Major activities of Pathfinder Plus' Hawaiian flights included detection of forest nutrient status, forest regrowth after damage caused by Hurricane Iniki in 1992, sediment/algal concentrations in coastal waters, and assessment of coral reef health. Pathfinder science activities were coordinated by NASA's Ames Research Center, Mountain View, California, and included researchers from the University of Hawaii and the University of California. Pathfinder is part of NASA's Environmental Research Aircraft and Sensor Technology (ERAST) program managed by NASA's Dryden Flight Research Center, Edwards, California. Pathfinder and Pathfinder Plus were designed, built, and operated by AeroVironment, Inc., Monrovia, California. Pathfinder had a 98.4-foot wing span and weighed 560 pounds. Pathfinder Plus has a 121-foot wing span and weighs about 700 pounds. Pathfinder was powered by six electric motors while Pathfinder Plus has eight. Pathfinder's solar arrays produced approximately 8,000 watts of power while Pathfinder Plus' solar arrays produce about 12,500 watts of power. Both Pathfinder aircraft were built primarily of composites, plastic, and foam.

1998-01-01

8

Pathfinder-Plus on flight over Hawaiian Islands  

NASA Technical Reports Server (NTRS)

Pathfinder-Plus on flight over Hawaiian Islands in 1998. Pathfinder was a remotely controlled, solar-powered flying wing, designed and built as a proof-of-concept vehicle for a much larger aircraft capable of flying at extremely high altitudes for weeks at a time. It was built by AeroVironment, Inc., a California company that developed the human-powered Gossamer Condor and Gossamer Albatross lightweight aircraft during the 1970s, and later made the solar-electric powered Gossamer Penguin and Solar Challenger. The basic configuration and concepts for Pathfinder were first realized with the HALSOL (High Altitude Solar) aircraft, built in 1983 by AeroVironment and the Lawrence Livermore Laboratory. Pathfinder was constructed of advanced composites, plastics, and foam, and despite a wingspan of nearly 100 feet, it weighed only about 600 pounds. Pathfinder was one of several unpiloted prototypes under study by NASA's ERAST (Environmental Research Aircraft and Sensor Technology) program, a NASA-industry alliance which is helping develop advanced technologies that will enable aircraft to study the earth's environment during extremely long flights at altitudes in excess of 100,000 feet. (See project description below for Pathfinder's conversion to Pathfinder Plus.) In 1998, the Pathfinder solar-powered flying wing (see its photographs and project description) was modified into the longer-winged Pathfinder Plus configuration and on Aug. 6, 1998, Pathfinder Plus set an altitude record (for propeller-driven aircraft) of approximately 80,285 feet at the Pacific Missile Range Facility. The goal of the Pathfinder Plus flights was to validate new solar, aerodynamic, propulsion, and systems technology developed for its successor, the Centurion, which was designed to reach and sustain altitudes in the 100,000-foot range. The Centurion was succeeded by the Helios Prototype with a goal of reaching and sustaining flight at an altitude of 100,000 feet and flying non-stop for at least 4 days above 50,000 feet. Major activities of Pathfinder Plus' Hawaiian flights included detection of forest nutrient status, forest regrowth after damage caused by Hurricane Iniki in 1992, sediment/algal concentrations in coastal waters, and assessment of coral reef health. Pathfinder science activities were coordinated by NASA's Ames Research Center, Mountain View, California, and included researchers from the University of Hawaii and the University of California. Pathfinder is part of NASA's Environmental Research Aircraft and Sensor Technology (ERAST) program managed by NASA's Dryden Flight Research Center, Edwards, California. Pathfinder and Pathfinder Plus were designed, built, and operated by AeroVironment, Inc., Monrovia, California. Pathfinder had a 98.4-foot wing span and weighed 560 pounds. Pathfinder Plus has a 121-foot wing span and weighs about 700 pounds. Pathfinder was powered by six electric motors while Pathfinder Plus has eight. Pathfinder's solar arrays produced approximately 8,000 watts of power while Pathfinder Plus' solar arrays produce about 12,500 watts of power. Both Pathfinder aircraft were built primarily of composites, plastic, and foam.

1998-01-01

9

New mapping techniques help assess the health of Hawaii's coral reefs  

USGS Publications Warehouse

The U.S. Geological Survey (USGS) is working closely with academic institutions and state and Federal agencies to assess the factors that affect the health of Hawaii's and our Nation's coral reefs. In order to establish a basis from which scientists can objectively detect changes in reef health, the USGS and its cooperators are applying many new techniques to the mapping and monitoring of coral reefs in Hawaii.

Field, M. E.; Chavez, P. S., Jr.; Evans, K. R.; Cochran, S. A.

2001-01-01

10

Pathfinder-Plus on flight over Hawaiian island N'ihau  

NASA Technical Reports Server (NTRS)

Pathfinder-Plus on a flight over the Hawaiian island of N'ihau in 1998. Pathfinder was a remotely controlled, solar-powered flying wing, designed and built as a proof-of-concept vehicle for a much larger aircraft capable of flying at extremely high altitudes for weeks at a time. It was built by AeroVironment, Inc., a California company that developed the human-powered Gossamer Condor and Gossamer Albatross lightweight aircraft during the 1970s, and later made the solar-electric powered Gossamer Penguin and Solar Challenger. The basic configuration and concepts for Pathfinder were first realized with the HALSOL (High Altitude Solar) aircraft, built in 1983 by AeroVironment and the Lawrence Livermore Laboratory. Pathfinder was constructed of advanced composites, plastics, and foam, and despite a wingspan of nearly 100 feet, it weighed only about 600 pounds. Pathfinder was one of several unpiloted prototypes under study by NASA's ERAST (Environmental Research Aircraft and Sensor Technology) program, a NASA-industry alliance which is helping develop advanced technologies that will enable aircraft to study the earth's environment during extremely long flights at altitudes in excess of 100,000 feet. (See project description below for Pathfinder's conversion to Pathfinder Plus.) In 1998, the Pathfinder solar-powered flying wing (see its photographs and project description) was modified into the longer-winged Pathfinder Plus configuration and on Aug. 6, 1998, Pathfinder Plus set an altitude record (for propeller-driven aircraft) of approximately 80,285 feet at the Pacific Missile Range Facility. The goal of the Pathfinder Plus flights was to validate new solar, aerodynamic, propulsion, and systems technology developed for its successor, the Centurion, which was designed to reach and sustain altitudes in the 100,000-foot range. The Centurion was succeeded by the Helios Prototype with a goal of reaching and sustaining flight at an altitude of 100,000 feet and flying non-stop for at least 4 days above 50,000 feet. Major activities of Pathfinder Plus' Hawaiian flights included detection of forest nutrient status, forest regrowth after damage caused by Hurricane Iniki in 1992, sediment/algal concentrations in coastal waters, and assessment of coral reef health. Pathfinder science activities were coordinated by NASA's Ames Research Center, Mountain View, California, and included researchers from the University of Hawaii and the University of California. Pathfinder is part of NASA's Environmental Research Aircraft and Sensor Technology (ERAST) program managed by NASA's Dryden Flight Research Center, Edwards, California. Pathfinder and Pathfinder Plus were designed, built, and operated by AeroVironment, Inc., Monrovia, California. Pathfinder had a 98.4-foot wing span and weighed 560 pounds. Pathfinder Plus has a 121-foot wing span and weighs about 700 pounds. Pathfinder was powered by six electric motors while Pathfinder Plus has eight. Pathfinder's solar arrays produced approximately 8,000 watts of power while Pathfinder Plus' solar arrays produce about 12,500 watts of power. Both Pathfinder aircraft were built primarily of composites, plastic, and foam.

1998-01-01

11

Pathfinder-Plus on a flight over Hawaiian island N'ihau  

NASA Technical Reports Server (NTRS)

Pathfinder-Plus on a flight over the Hawaiian island of N'ihau in 1998. Pathfinder was a remotely controlled, solar-powered flying wing, designed and built as a proof-of-concept vehicle for a much larger aircraft capable of flying at extremely high altitudes for weeks at a time. It was built by AeroVironment, Inc., a California company that developed the human-powered Gossamer Condor and Gossamer Albatross lightweight aircraft during the 1970s, and later made the solar-electric powered Gossamer Penguin and Solar Challenger. The basic configuration and concepts for Pathfinder were first realized with the HALSOL (High Altitude Solar) aircraft, built in 1983 by AeroVironment and the Lawrence Livermore Laboratory. Pathfinder was constructed of advanced composites, plastics, and foam, and despite a wingspan of nearly 100 feet, it weighed only about 600 pounds. Pathfinder was one of several unpiloted prototypes under study by NASA's ERAST (Environmental Research Aircraft and Sensor Technology) program, a NASA-industry alliance which is helping develop advanced technologies that will enable aircraft to study the earth's environment during extremely long flights at altitudes in excess of 100,000 feet. (See project description below for Pathfinder's conversion to Pathfinder Plus.) In 1998, the Pathfinder solar-powered flying wing (see its photographs and project description) was modified into the longer-winged Pathfinder Plus configuration and on Aug. 6, 1998, Pathfinder Plus set an altitude record (for propeller-driven aircraft) of approximately 80,285 feet at the Pacific Missile Range Facility. The goal of the Pathfinder Plus flights was to validate new solar, aerodynamic, propulsion, and systems technology developed for its successor, the Centurion, which was designed to reach and sustain altitudes in the 100,000-foot range. The Centurion was succeeded by the Helios Prototype with a goal of reaching and sustaining flight at an altitude of 100,000 feet and flying non-stop for at least 4 days above 50,000 feet. Major activities of Pathfinder Plus' Hawaiian flights included detection of forest nutrient status, forest regrowth after damage caused by Hurricane Iniki in 1992, sediment/algal concentrations in coastal waters, and assessment of coral reef health. Pathfinder science activities were coordinated by NASA's Ames Research Center, Mountain View, California, and included researchers from the University of Hawaii and the University of California. Pathfinder is part of NASA's Environmental Research Aircraft and Sensor Technology (ERAST) program managed by NASA's Dryden Flight Research Center, Edwards, California. Pathfinder and Pathfinder Plus were designed, built, and operated by AeroVironment, Inc., Monrovia, California. Pathfinder had a 98.4-foot wing span and weighed 560 pounds. Pathfinder Plus has a 121-foot wing span and weighs about 700 pounds. Pathfinder was powered by six electric motors while Pathfinder Plus has eight. Pathfinder's solar arrays produced approximately 8,000 watts of power while Pathfinder Plus' solar arrays produce about 12,500 watts of power. Both Pathfinder aircraft were built primarily of composites, plastic, and foam.

1998-01-01

12

Pathfinder-Plus on flight near Hawaiian island N'ihau  

NASA Technical Reports Server (NTRS)

Pathfinder-Plus on a flight with the Hawaiian island of N'ihau in the background. Pathfinder was a remotely controlled, solar-powered flying wing, designed and built as a proof-of-concept vehicle for a much larger aircraft capable of flying at extremely high altitudes for weeks at a time. It was built by AeroVironment, Inc., a California company that developed the human-powered Gossamer Condor and Gossamer Albatross lightweight aircraft during the 1970s, and later made the solar-electric powered Gossamer Penguin and Solar Challenger. The basic configuration and concepts for Pathfinder were first realized with the HALSOL (High Altitude Solar) aircraft, built in 1983 by AeroVironment and the Lawrence Livermore Laboratory. Pathfinder was constructed of advanced composites, plastics, and foam, and despite a wingspan of nearly 100 feet, it weighed only about 600 pounds. Pathfinder was one of several unpiloted prototypes under study by NASA's ERAST (Environmental Research Aircraft and Sensor Technology) program, a NASA-industry alliance which is helping develop advanced technologies that will enable aircraft to study the earth's environment during extremely long flights at altitudes in excess of 100,000 feet. (See project description below for Pathfinder's conversion to Pathfinder Plus.) In 1998, the Pathfinder solar-powered flying wing (see its photographs and project description) was modified into the longer-winged Pathfinder Plus configuration and on Aug. 6, 1998, Pathfinder Plus set an altitude record (for propeller-driven aircraft) of approximately 80,285 feet at the Pacific Missile Range Facility. The goal of the Pathfinder Plus flights was to validate new solar, aerodynamic, propulsion, and systems technology developed for its successor, the Centurion, which was designed to reach and sustain altitudes in the 100,000-foot range. The Centurion was succeeded by the Helios Prototype with a goal of reaching and sustaining flight at an altitude of 100,000 feet and flying non-stop for at least 4 days above 50,000 feet. Major activities of Pathfinder Plus' Hawaiian flights included detection of forest nutrient status, forest regrowth after damage caused by Hurricane Iniki in 1992, sediment/algal concentrations in coastal waters, and assessment of coral reef health. Pathfinder science activities were coordinated by NASA's Ames Research Center, Mountain View, California, and included researchers from the University of Hawaii and the University of California. Pathfinder is part of NASA's Environmental Research Aircraft and Sensor Technology (ERAST) program managed by NASA's Dryden Flight Research Center, Edwards, California. Pathfinder and Pathfinder Plus were designed, built, and operated by AeroVironment, Inc., Monrovia, California. Pathfinder had a 98.4-foot wing span and weighed 560 pounds. Pathfinder Plus has a 121-foot wing span and weighs about 700 pounds. Pathfinder was powered by six electric motors while Pathfinder Plus has eight. Pathfinder's solar arrays produced approximately 8,000 watts of power while Pathfinder Plus' solar arrays produce about 12,500 watts of power. Both Pathfinder aircraft were built primarily of composites, plastic, and foam.

1998-01-01

13

Reef Check  

NSDL National Science Digital Library

Reef Check, headquartered at the Institute of the Environment at the University of California Los Angeles, is a "volunteer, community-based monitoring protocol designed to measure the health of coral reefs on a global scale." With scientific reef surveys conducted in over 60 countries and territories, Reef Check has been able to track global trends in reef health to better inform possible conservation strategies. Visitors to the Reef Check Web site can read result summaries for the 1997-2001 monitoring period, and check out the organization's current and archived newsletters. Other resources include information on survey methods, Reef Check publications, a species identification guide, and other resources geared mainly toward Reef Check volunteers.

14

Pathfinder-Plus on flight over Hawaiian Islands, with N'ihau and Lehua in the background  

NASA Technical Reports Server (NTRS)

Pathfinder-Plus on flight over Hawaiian Islands, with N'ihau and Lehua in the background. Pathfinder was a remotely controlled, solar-powered flying wing, designed and built as a proof-of-concept vehicle for a much larger aircraft capable of flying at extremely high altitudes for weeks at a time. It was built by AeroVironment, Inc., a California company that developed the human-powered Gossamer Condor and Gossamer Albatross lightweight aircraft during the 1970s, and later made the solar-electric powered Gossamer Penguin and Solar Challenger. The basic configuration and concepts for Pathfinder were first realized with the HALSOL (High Altitude Solar) aircraft, built in 1983 by AeroVironment and the Lawrence Livermore Laboratory. Pathfinder was constructed of advanced composites, plastics, and foam, and despite a wingspan of nearly 100 feet, it weighed only about 600 pounds. Pathfinder was one of several unpiloted prototypes under study by NASA's ERAST (Environmental Research Aircraft and Sensor Technology) program, a NASA-industry alliance which is helping develop advanced technologies that will enable aircraft to study the earth's environment during extremely long flights at altitudes in excess of 100,000 feet. (See project description below for Pathfinder's conversion to Pathfinder Plus.) In 1998, the Pathfinder solar-powered flying wing (see its photographs and project description) was modified into the longer-winged Pathfinder Plus configuration and on Aug. 6, 1998, Pathfinder Plus set an altitude record (for propeller-driven aircraft) of approximately 80,285 feet at the Pacific Missile Range Facility. The goal of the Pathfinder Plus flights was to validate new solar, aerodynamic, propulsion, and systems technology developed for its successor, the Centurion, which was designed to reach and sustain altitudes in the 100,000-foot range. The Centurion was succeeded by the Helios Prototype with a goal of reaching and sustaining flight at an altitude of 100,000 feet and flying non-stop for at least 4 days above 50,000 feet. Major activities of Pathfinder Plus' Hawaiian flights included detection of forest nutrient status, forest regrowth after damage caused by Hurricane Iniki in 1992, sediment/algal concentrations in coastal waters, and assessment of coral reef health. Pathfinder science activities were coordinated by NASA's Ames Research Center, Mountain View, California, and included researchers from the University of Hawaii and the University of California. Pathfinder is part of NASA's Environmental Research Aircraft and Sensor Technology (ERAST) program managed by NASA's Dryden Flight Research Center, Edwards, California. Pathfinder and Pathfinder Plus were designed, built, and operated by AeroVironment, Inc., Monrovia, California. Pathfinder had a 98.4-foot wing span and weighed 560 pounds. Pathfinder Plus has a 121-foot wing span and weighs about 700 pounds. Pathfinder was powered by six electric motors while Pathfinder Plus has eight. Pathfinder's solar arrays produced approximately 8,000 watts of power while Pathfinder Plus' solar arrays produce about 12,500 watts of power. Both Pathfinder aircraft were built primarily of composites, plastic, and foam.

1998-01-01

15

LISA Pathfinder  

NASA Technical Reports Server (NTRS)

USA Pathfinder is a space mission dedicated to demonstrating technology for the Laser Interferometer Space Antenna (LISA). LISA is a joint ESA/NASA mission to detect low-frequency gravitational waves on the 0.0001 to 0.1 Hz frequency band. LISA is expected to observe 100's of merging massive black hole binaries out z-15, tens of thousands of close compact binary systems in the Milky Way, merging intermediate-mass black hole binaries, tens of stellar-mass black holes falling into supermassive black holes in galactic centers, and possibly other exotic sources. Several critical LISA technologies have not been demonstrated at the requisite level of performance. In spaceflight, and some fight hardware cannot be tested in a 1-g environment. Hence, the LISA Pathfinder mission is being implemented to demonstrate these critical LISA technologies in a relevant flight environment. LISA Pathfinder mimics one arm of the LISA constellation by shrinking the 5-million-kilometer armlength down to a few tens of centimeters. The experimental concept is to measure the relative separation between two test masses nominally following their own geodesics, and thereby determine the relative residual acceleration between them near 1 mHz, about a decade above the lowest frequency required by LISA. To implement such a concept, disturbances on the test masses must be kept very small by many design features, but chiefly by "drag-free" flight. A drag-free spacecraft follows a free-falling test mass which it encloses, but has no mechanical connection to. The spacecraft senses it's orientation and separation with respect to the proof mass, and its propulsion system is commanded to keep the spacecraft centered about the test mass. Thus, the spacecraft shields the test mass from most external influences, and minimizes the effect of force gradients arising from the spacecraft, and acting on the test mass. LISA Pathfinder will compare the geodesic of one test mass against that of the other. Only a metrology system based on interferometry can achieve the displacement sensitivity. Interferometers monitor the separation of both test masses with a sensitivity comparable to that required by LISA, and using the same technologies. LISA Pathfinder is scheduled to be launched in the first half of 1020 to a Lissajous orbit around the first Sun-Earth Lagrange point, L1. In addition to a complete European technology package (the LISA Technology Package, or LTP), LISA Pathfinder will also carry thrusters and software, known as ST-7, a part of NASA's New Millennium Program.

Stebbins, Robin

2008-01-01

16

Turning science into health solutions: KEMRI's challenges as Kenya's health product pathfinder  

PubMed Central

Background A traditional pathway for developing new health products begins with public research institutes generating new knowledge, and ends with the private sector translating this knowledge into new ventures. But while public research institutes are key drivers of basic research in sub-Saharan Africa, the private sector is inadequately prepared to commercialize ideas that emerge from these institutes, resulting in these institutes taking on the role of product development themselves to alleviate the local disease burden. In this article, the case study method is used to analyze the experience of one such public research institute: the Kenya Medical Research Institute (KEMRI). Discussion Our analysis indicates that KEMRI’s product development efforts began modestly, and a manufacturing facility was constructed with a strategy for the facility’s product output which was not very successful. The intended products, HIV and Hepatitis B diagnostic kits, had a short product life cycle, and an abrupt change in regulatory requirements left KEMRI with an inactive facility. These problems were the result of poor innovation management capacity, variability in domestic markets, lack of capital to scale up technologies, and an institutional culture that lacked innovation as a priority. However, KEMRI appears to have adapted by diversifying its product line to mitigate risk and ensure continued use of its manufacturing facility. It adopted an open innovation business model which linked it with investors, research partnerships, licensing opportunities, and revenue from contract manufacturing. Other activities that KEMRI has put in place over several years to enhance product development include the establishment of a marketing division, development of an institutional IP policy, and training of its scientists on innovation management. Summary KEMRI faced many challenges in its attempt at health product development, including shifting markets, lack of infrastructure, inadequate financing, and weak human capital with respect to innovation. However, it overcame them through diversification, partnerships and changes in culture. The findings could have implications for other research institutes in Sub-Saharan Africa seeking to develop health products. Such institutes must analyze potential demand and uptake, yet be prepared to face the unexpected and develop appropriate risk-mitigating strategies.

2010-01-01

17

Abrolhos Bank Reef Health Evaluated by Means of Water Quality, Microbial Diversity, Benthic Cover, and Fish Biomass Data  

PubMed Central

The health of the coral reefs of the Abrolhos Bank (southwestern Atlantic) was characterized with a holistic approach using measurements of four ecosystem components: (i) inorganic and organic nutrient concentrations, [1] fish biomass, [1] macroalgal and coral cover and (iv) microbial community composition and abundance. The possible benefits of protection from fishing were particularly evaluated by comparing sites with varying levels of protection. Two reefs within the well-enforced no-take area of the National Marine Park of Abrolhos (Parcel dos Abrolhos and California) were compared with two unprotected coastal reefs (Sebastião Gomes and Pedra de Leste) and one legally protected but poorly enforced coastal reef (the “paper park” of Timbebas Reef). The fish biomass was lower and the fleshy macroalgal cover was higher in the unprotected reefs compared with the protected areas. The unprotected and protected reefs had similar seawater chemistry. Lower vibrio CFU counts were observed in the fully protected area of California Reef. Metagenome analysis showed that the unprotected reefs had a higher abundance of archaeal and viral sequences and more bacterial pathogens, while the protected reefs had a higher abundance of genes related to photosynthesis. Similar to other reef systems in the world, there was evidence that reductions in the biomass of herbivorous fishes and the consequent increase in macroalgal cover in the Abrolhos Bank may be affecting microbial diversity and abundance. Through the integration of different types of ecological data, the present study showed that protection from fishing may lead to greater reef health. The data presented herein suggest that protected coral reefs have higher microbial diversity, with the most degraded reef (Sebastião Gomes) showing a marked reduction in microbial species richness. It is concluded that ecological conditions in unprotected reefs may promote the growth and rapid evolution of opportunistic microbial pathogens.

Bruce, Thiago; Meirelles, Pedro M.; Garcia, Gizele; Paranhos, Rodolfo; Rezende, Carlos E.; de Moura, Rodrigo L.; Filho, Ronaldo-Francini; Coni, Ericka O. C.; Vasconcelos, Ana Tereza; Amado Filho, Gilberto; Hatay, Mark; Schmieder, Robert; Edwards, Robert; Dinsdale, Elizabeth; Thompson, Fabiano L.

2012-01-01

18

Pathfinder Program  

NASA Technical Reports Server (NTRS)

The topics in this viewgraph include: 1) High visibility Flight Projects; 2) Pathfinder Flight Experiments; 3) X-37 Configuration Modification Options; 4) Flight Testing for a Multistage Reusable System; 5) X-34 Vehicle Description; 6) X-34 Expanded View; 7) Vehicle Size Comparison; 8) X-34 Experiment Status; 9) Government Participation; 10) Government and Industry Participants; 11) X-34 Project Status; 12) X-34 Captive Carry Fight; 13) Little Joe III; 14) Fastpac; and 15) Islunar Tug.

London, John R., III; Rogacki, Row (Technical Monitor)

2000-01-01

19

Mars Pathfinder  

NSDL National Science Digital Library

This extensive site from NASA's Jet Propulsion Laboratory is divided into two parts. The first features information available at the time of Pathfinder's 1997 landing on Mars while the second part focuses on information available at the end of the mission. Each part presents archived news and science articles, data and general mission information as well as many images. The site is searchable and includes links to related information.

Laboratory, Nasa J.

20

Assessment of the water quality and ecosystem health of the Great Barrier Reef (Australia): conceptual models.  

PubMed

Run-off containing increased concentrations of sediment, nutrients, and pesticides from land-based anthropogenic activities is a significant influence on water quality and the ecologic conditions of nearshore areas of the Great Barrier Reef World Heritage Area, Australia. The potential and actual impacts of increased pollutant concentrations range from bioaccumulation of contaminants and decreased photosynthetic capacity to major shifts in community structure and health of mangrove, coral reef, and seagrass ecosystems. A detailed conceptual model underpins and illustrates the links between the main anthropogenic pressures or threats (dry-land cattle grazing and intensive sugar cane cropping) and the production of key contaminants or stressors of Great Barrier Reef water quality. The conceptual model also includes longer-term threats to Great Barrier Reef water quality and ecosystem health, such as global climate change, that will potentially confound direct model interrelationships. The model recognises that system-specific attributes, such as monsoonal wind direction, rainfall intensity, and flood plume residence times, will act as system filters to modify the effects of any water-quality system stressor. The model also summarises key ecosystem responses in ecosystem health that can be monitored through indicators at catchment, riverine, and marine scales. Selected indicators include riverine and marine water quality, inshore coral reef and seagrass status, and biota pollutant burdens. These indicators have been adopted as components of a long-term monitoring program to enable assessment of the effectiveness of change in catchment-management practices in improving Great Barrier Reef (and adjacent catchment) water quality under the Queensland and Australian Governments' Reef Water Quality Protection Plan. PMID:17786511

Haynes, David; Brodie, Jon; Waterhouse, Jane; Bainbridge, Zoe; Bass, Deb; Hart, Barry

2007-12-01

21

Decigo Pathfinder  

NASA Astrophysics Data System (ADS)

DECIGO Pathfinder (DPF) is a small ( 350 kg) satellite orbiting the Earth. DPF was originally proposed as the first milestone mission for a future space gravitational-wave (GW) antenna, DECi-hertz Interferometer Gravitational wave Observatory (DECIGO). In addition to the purpose of space demonstrations for DECIGO, DPF has scientific objectives: observation of GWs from black-hole mergers and monitor of Earth's gravity, as well as establishment of space technologies for high-precision measurements. In this paper, we review the conceptual design, scientific outcomes and the current status of DPF.

Ando, Masaki; The Decigo Working Group,

2013-01-01

22

Pathfinders: Science  

NSDL National Science Digital Library

The Indianapolis Marion County Public Library provides these educational subject specific pathfinders "that contain a list of library materials, web sites, and other information about a topic." The Science section includes topics focused on how the human body works, including the circulatory, digestive, excretory, muscular, nervous, respiratory, and skeletal systems. Each topic includes a detailed diagram and facts about the body system, and a variety of helpful books and online resources appropriate for children. This site is a useful resource for gathering information on a specific subject or browsing a variety of topics.

23

Mapping Health of Bonaire Coral Reefs Using a Lightweight Hyperspectral Mapping System - First Results  

NASA Astrophysics Data System (ADS)

The Dutch Caribbean island of Bonaire is one of the world's top diving holiday destinations much due to its clear waters and healthy coral reefs. The coral reefs surround the western side of the island as an approximately 50-150m wide band. However, the general consensus is that the extent and biodiversity of the Bonarian coral reef is constantly decreasing due to anthropogenic pressures. The last extensive study of the health of the reef ecosystem was performed in 1985 by Van Duyl creating an underwater atlas. In order to update this atlas of Bonaire's coral reefs, in October 2013, a hyperspectral mapping campaign was performed using the WUR Hyperspectral Mapping System (HYMSY). A dive validation campaign has been planned for early 2014. The HYMSY consists of a custom pushbroom spectrometer (range 450-950nm, FWHM 9nm, ~20 lines/s, 328 pixels/line), a consumer camera (collecting 16MPix raw image every 2 seconds), a GPS-Inertia Navigation System (GPS-INS), and synchronization and data storage units. The weight of the system at take-off is 2.0kg allowing it to be mounted on varying platforms. In Bonaire the system was flown on two platforms. (1) on a Cessna airplane to provide a coverage for whole west side of the island with a hyperspectral map in 2-4m resolution and a RGB orthomosaic in 15cm resolution, and (2) on a kite pulled by boat and car to provide a subset coverage in higher resolution. In this presentation we will present our mapping technique and first results including a preliminary underwater atlas and conclusions on reef development.

Suomalainen, Juha; Mucher, Sander; Kooistra, Lammert; Meesters, Erik

2014-05-01

24

Use of Integrated Landscape Indicators to Evaluate the Health of Linked Watersheds and Coral Reef Environments in the Hawaiian Islands  

NASA Astrophysics Data System (ADS)

A linkage between the condition of watersheds and adjacent nearshore coral reef communities is an assumed paradigm in the concept of integrated coastal management. However, quantitative evidence for this "catchment to sea" or "ridge to reef" relationship on oceanic islands is lacking and would benefit from the use of appropriate marine and terrestrial landscape indicators to quantify and evaluate ecological status on a large spatial scale. To address this need, our study compared the Hawai`i Watershed Health Index (HI-WHI) and Reef Health Index (HI-RHI) derived independently of each other over the past decade. Comparisons were made across 170 coral reef stations at 52 reef sites adjacent to 42 watersheds throughout the main Hawaiian Islands. A significant positive relationship was shown between the health of watersheds and that of adjacent reef environments when all sites and depths were considered. This relationship was strongest for sites facing in a southerly direction, but diminished for north facing coasts exposed to persistent high surf. High surf conditions along the north shore increase local wave driven currents and flush watershed-derived materials away from nearshore waters. Consequently, reefs in these locales are less vulnerable to the deposition of land derived sediments, nutrients and pollutants transported from watersheds to ocean. Use of integrated landscape health indices can be applied to improve regional-scale conservation and resource management.

Rodgers, Ku`ulei S.; Kido, Michael H.; Jokiel, Paul L.; Edmonds, Tim; Brown, Eric K.

2012-07-01

25

NOAA's Coral Reef  

NSDL National Science Digital Library

In an effort to centralize information on Coral Reefs, the National Oceanic and Atmospheric Administration (NOAA) has launched this site on Coral Reefs. The site serves both as a news resource (see the frequently updated News Releases section) as well as a basic information resource (see Year of the Reef 1997 and Coral Reef Photos) on coral reefs. For information on current research (scientific and citizen), see the Coral Health and Monitoring Program, the Great American Fish Count, or the Coral Reef Initiative sections. Additionally, a dozen Coral Reef Links point users to further resources. For the pure enthusiast or beginning college student, this site serves as a fine entry-way into learning about Coral Reefs.

26

Mars Pathfinder Preliminary Results  

Microsoft Academic Search

Pathfinder plays a key role as the first of the Surveyor series and as the first Discovery project to complete its mission. On July 4 the Pathfinder lands at Ares Vallis chosen as a grab-bag sample of small rocks washed down from the highland regions by the ancient catastrophic floods that once inundated the region. A multi-spectral, stereoscopic camera (IMP)

P. H. Smith

1997-01-01

27

Health of the coral reefs at the US Navy Base, Guantánamo Bay, Cuba: A preliminary report based on isotopic records from gorgonians.  

PubMed

Specimens of the gorgonian Plexaura homomalla were sampled from several areas along the fringing reefs fronting the United States Naval Base at Guantánamo Bay, Cuba. Sample coverage extended from apparently healthy reefs in oceanic waters to declining reefs located in the plume of the drainage from upper parts of Guantánamo Bay. Tentacle tips were excised, and trunk sections were cut and polished. Stable isotope ratios of nitrogen (?(15)N) and carbon indicate a strong correlation of reef health with proximity to the plume of the river. Of all the worldwide cases in which land-based sources of pollution have impacted reefs, this one may well be the most intractable. The US Navy has jurisdiction over the reefs, with the obligation to protect them, yet the threat comes down the river from Cuba. PMID:24735775

Risk, Michael J; Burchell, Meghan; Brunton, Dalston A; McCord, Michael R

2014-06-15

28

The LISA Pathfinder Mission  

Microsoft Academic Search

LISA Pathfinder is an ESA mission designed to pave the way for the joint ESA\\/NASA Laser Interferometer Space Antenna (LISA) mission by testing in flight the critical technologies required for space-borne gravitational wave detection. It will put two test masses in a near-perfect gravitational free-fall and measure their motion with unprecedented accuracy. LISA Pathfinder will carry two technology payloads, the

Robin T. Stebbins

2007-01-01

29

Coral Reefs Under Stress  

NSDL National Science Digital Library

Coral reefs are more critical to an oceanâÂÂs health than you might think, and the effects of climate change and ocean acidification are effectively damaging and destroying most reefs in the world. Coral reefs provide many important ecosystem services, including: providing food, shelter, and meeting places for thousands of animals; anchoring sand for recreational beaches; and supplying building materials for remote peoples.

Peter Mumby (University of Exeter;)

2009-10-05

30

A model of the effects of land-based, human activities on the health of coral reefs in the Great Barrier Reef and in Fouha Bay, Guam, Micronesia  

Microsoft Academic Search

A model is proposed to explain coral and algal abundance on coastal coral reefs as a function of spike-like natural disturbances from tropical cyclones and turbid river floods, followed by long recovery periods where the rate of reef recovery depends on ambient water and substratum quality. The model includes competition for space between corals and algae, coral recruitment and reef

Eric Wolanski; Robert H. Richmond; Laurence McCook

2004-01-01

31

Assessing community values for reducing agricultural emissions to improve water quality and protect coral health in the Great Barrier Reef  

NASA Astrophysics Data System (ADS)

Policymakers wanting to increase protection of the Great Barrier Reef from pollutants generated by agriculture need to identify when measures to improve water quality generate benefits to society that outweigh the costs involved. The research reported in this paper makes a contribution in several ways. First, it uses the improved science understanding about the links between management changes and reef health to bring together the analysis of costs and benefits of marginal changes, helping to demonstrate the appropriate way of addressing policy questions relating to reef protection. Second, it uses the scientific relationships to frame a choice experiment to value the benefits of improved reef health, with the results of mixed logit (random parameter) models linking improvements explicitly to changes in "water quality units." Third, the research demonstrates how protection values are consistent across a broader population, with some limited evidence of distance effects. Fourth, the information on marginal costs and benefits that are reported provide policymakers with information to help improve management decisions. The results indicate that while there is potential for water quality improvements to generate net benefits, high cost water quality improvements are generally uneconomic. A major policy implication is that cost thresholds for key pollutants should be set to avoid more expensive water quality proposals being selected.

Rolfe, John; Windle, Jill

2011-12-01

32

Mapping and monitoring the health and vitality of coral reefs from satellite: a biospheric approach.  

PubMed

Biospheric studies of coral reefs require a planetary perspective that only remote sensing from space can provide. This article reviews aspects of monitoring and mapping coral reefs using Landsat and Spot satellite images. It details design considerations for developing a sensor for equatorial orbiting spacecraft, including spectral characteristics of living corals and the spatial resolution required to map coral reef communities. Possible instrumentation choices include computer techniques, filtered imagers, push-broom spectral imagery, and a newly developed hyperspectral imaging scheme using tomographic reconstruction. We compare the salient features of each technique and describe concepts for a payload to conduct planetary-scale coral reef monitoring. PMID:11543553

Dustan, P; Chakrabarti, S; Alling, A

2000-01-01

33

Martian Surface & Pathfinder Airbags  

NASA Technical Reports Server (NTRS)

This image of the Martian surface was taken in the afternoon of Mars Pathfinder's first day on Mars. Taken by the Imager for Mars Pathfinder (IMP camera), the image shows a diversity of rocks strewn in the foreground. A hill is visible in the distance (the notch within the hill is an image artifact). Airbags are seen at the lower right.

The IMP is a stereo imaging system with color capability provided by 24 selectable filters -- twelve filters per 'eye.' It stands 1.8 meters above the Martian surface, and has a resolution of two millimeters at a range of two meters.

Mars Pathfinder is the second in NASA's Discovery program of low-cost spacecraft with highly focused science goals. The Jet Propulsion Laboratory, Pasadena, CA, developed and manages the Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. JPL is an operating division of the California Institute of Technology (Caltech). The Imager for Mars Pathfinder (IMP) was developed by the University of Arizona Lunar and Planetary Laboratory under contract to JPL. Peter Smith is the Principal Investigator.

1997-01-01

34

Spectral discrimination of coral reef bottom types  

Microsoft Academic Search

Degradation of coral reefs is a major environmental problem worldwide. There is a strong management need for cost-effective assessment of environmental health and reef conditions over large regions in remote areas. Remote sensing could be an ideal tool for monitoring coral reefs and related ecosystems in cases where different coral reef substrates are spectrally resolvable. The aim of the present

T. Kutser; W. Skirving; J. Parslow; L. Clementson; T. Done; M. Wakeford; I. Miller

2001-01-01

35

Coral Reefs  

NSDL National Science Digital Library

This page offers information on coral reefs. Coral reefs are often refered to as the rainforest of the oceans. This exploration will help you to see why that is. Follow these links to learn about coral reefs. This link will take you to Florida where a girl will take guide you over a coral reef. Coral Kid This site ...

Amsden

2009-11-19

36

The LISA Pathfinder Mission  

NASA Astrophysics Data System (ADS)

LISA Pathfinder, the second of the European Space Agency's Small Missions for Advanced Research in Technology (SMART), is a dedicated technology validation mission for future interferometric spaceborne gravitational wave observatories, for example the proposed eLISA mission. The technologies required for eLISA are many and extremely challenging. This coupled with the fact that some flight hardware cannot be fully tested on ground due to Earth-induced noise, led to the implementation of the LISA Pathfinder mission to test the critical eLISA technologies in a flight environment. LISA Pathfinder essentially mimics one arm of the eLISA constellation by shrinking the 1 million kilometre armlength down to a few tens of centimetres, giving up the sensitivity to gravitational waves, but keeping the measurement technology: the distance between the two test masses is measured using a laser interferometric technique similar to one aspect of the eLISA interferometry system. The scientific objective of the LISA Pathfinder mission consists then of the first in-flight test of low frequency gravitational wave detection metrology. Here I will present an overview of the mission, focusing on scientific and technical goals, followed by the current status of the project.

McNamara, Paul

2013-04-01

37

Martian terrain near Pathfinder  

NASA Technical Reports Server (NTRS)

Large boulders are visible in this enlargement of pictures taken by the Mars Pathfinder lander camera on July 4, 1997. The landing site is in the dry flood channel named Ares Valles. The boulders probably represent deposits from one of the catastrophic floods that carved the ancient channel. Between the rocks is brownish windblown soil. The gray-tan sky results from dust particles in the atmosphere.

Pathfinder, a low-cost Discovery mission, is the first of a new fleet of spacecraft that are planned to explore Mars over the next ten years. Mars Global Surveyor, already en route, arrives at Mars on September 11 to begin a two year orbital reconnaissance of the planet's composition, topography, and climate. Additional orbiters and landers will follow every 26 months.

Mars Pathfinder was developed and managed by the Jet Propulsion Laboratory for NASA's Office of Space Science, Washington, D.C. JPL is an operating division of the California Institute of Technology (Caltech). The Imager for Mars Pathfinder (IMP) was developed by the University of Arizona Lunar and Planetary Laboratory under contract to JPL. Peter Smith is the Principal Investigator.

1997-01-01

38

The LISA Pathfinder Mission  

NASA Astrophysics Data System (ADS)

LISA Pathfinder is a dedicated technology demonstration space mission for the Laser Interferometer Space Antenna (LISA), a NASA/ESA collaboration to operate a space-based observatory for gravitational waves in the milliHertz band. Although the formal partnership between the agencies was dissolved in the Spring of 2011, both agencies are actively pursuing concepts for LISA-like gravitational wave observatories. These concepts take advantage of the significant technology development efforts that have already been made, especially those of the LISA Pathfinder mission. LISA Pathfinder, which is in the late stages of implementation, will place two test masses in drag-free flight and measure the relative acceleration between them. This measurement will validate a number of technologies that are critical to LISA-like gravitational wave instruments including sensing and control of the test masses, drag-free control laws, micro-Newton thrusters, and picometer-level laser metrology. We will present the current status of the LISA Pathfinder mission and associated activities.

Thorpe, James; Namara, P. W. Mc.; LISA Pathfinder Team

2012-01-01

39

The LISA Pathfinder Mission  

NASA Technical Reports Server (NTRS)

LISA Pathfinder is a dedicated technology demonstration space mission for the Laser Interferometer Space Antenna (LISA), a NASA/ESA collaboration to operate a space-based observatory for gravitational waves in the milli-Hertz band. Although the formal partnership between the agencies was dissolved in the Spring of 2011, both agencies are actively pursuing concepts for LISA-like gravitational wave observatories. These concepts take advantage of the significant technology development efforts that have already been made, especially those of the LISA Pathfinder mission. LISA Pathfinder, which is in the late stages of implementation, will place two test masses in drag-free flight and measure the relative acceleration between them. This measurement will validate a number of technologies that are critical to LISA-like gravitational wave instruments including sensing and control of the test masses, drag-free control laws, microNewton thrusters, and picometer-level laser metrology. We will present the current status of the LISA Pathfinder mission and associated activities.

Thorpe, james; McNamara, P. W.

2011-01-01

40

Constellation Pathfinder Technology Development  

NASA Technical Reports Server (NTRS)

This final report describes the efforts accomplished during the grant s period of performance, covering the period of 15 March 2001 to 14 March 2004, of an unsolicited NASA proposal entitled Constellation Pathfinder Technology Development. We have completed the goals set forth in the proposed research objectives. An overview of these studies is summarized.

Spence, Harlan E.

2004-01-01

41

Pathfinder Spies Dust Devils  

NASA Technical Reports Server (NTRS)

This set of images from NASA's 1997 Pathfinder mission highlight the dust devils that gust across the surface of Mars. The right image shows the dusty martian sky as our eye would see it. The left image has been enhanced to expose the dust devils that lurk in the hazy sky.

2004-01-01

42

Reef ED  

NSDL National Science Digital Library

Great Barrier Reef Marine Park Authority's resource and activity center for teachers and students. Find teaching units for K-12 on: coral reef habitats and marine life; human dependence and impacts on the reef; biodiversity and threatened species; coastal zone and reef management. Lesson plans offer objectives, inquiry learning focus activities, resources, class or field activities. Student pages contain: marine life profiles; reef conservation projects; role playing activities; web investigations. Excellent image library (stills and video).

43

The LISA Pathfinder Mission  

NASA Astrophysics Data System (ADS)

Laser Interferometer Space Antenna (LISA) Pathfinder (formerly known as SMART-2) is a European Space Agency mission designed to pave the way for the joint ESA/NASA LISA mission by testing in flight the critical technologies required for space borne gravitational wave detection; it will put two test masses in a near-perfect gravitational free-fall and control and measure their motion with unprecedented accuracy. This is achieved through technology comprising inertial sensors, high precision laser metrology, drag-free control and an ultra precise micro-Newton propulsion system. LISA Pathfinder (LPF) essentially mimics one arm of space-borne gravitational wave detectors by shrinking the million kilometer scale armlengths down to a few tens of centimeters, giving up the sensitivity to gravitational waves, but keeping the measurement technology. The scientific objective of the LPF mission consists then of the first in-flight test of low frequency gravitational wave detection metrology.

McNamara, Paul W.

2013-01-01

44

VR for Mars Pathfinder  

NASA Technical Reports Server (NTRS)

Virtual reality (VR) technology has played an integral role for Mars Pathfinder mission, operations Using an automated machine vision algorithm, the 3d topography of the Martian surface was rapidly recovered fro -a the stereo images captured. by the Tender camera to produce photo-realistic 3d models, An advanced, interface was developed for visualization and interaction with. the virtual environment of the Pathfinder landing site for mission scientists at the Space Flight Operations Facility of the Jet Propulsion Laboratory. The VR aspect of the display allowed mission scientists to navigate on Mars in Bud while remaining here on Earth, thus improving their spatial awareness of the rock field that surrounds the lenders Measurements of positions, distances and angles could be easily extracted from the topographic models, providing valuable information for science analysis and mission. planning. Moreover, the VR map of Mars has also been used to assist with the archiving and planning of activities for the Sojourner rover.

Blackmon, Theodore

1998-01-01

45

The LISA Pathfinder mission  

Microsoft Academic Search

LISA Pathfinder (formerly known as SMART-2) is an ESA mission designed to pave the way for the joint ESA\\/NASA Laser Interferometer Space Antenna (LISA) mission by testing in flight the critical technologies required for space-borne gravitational wave detection: it will put two test masses in a near-perfect gravitational free-fall and control and measure their motion with unprecedented accuracy. This is

Paul McNamara

2008-01-01

46

The LISA Pathfinder Mission  

NASA Astrophysics Data System (ADS)

LISA Pathfinder (formerly known as SMART-2) is an European Space Agency mission designed to pave the way for the joint ESA/NASA Laser Interferometer Space Antenna (LISA) mission by testing in flight the critical technologies required for space-borne gravitational wave detection; it will put two test masses in a near-perfect gravitational free-fall and control and measure their motion with unprecedented accuracy. This is achieved through technology comprising inertial sensors, high precision laser metrology, drag-free control, and an ultra precise micro-Newton propulsion system. LISA Pathfinder (LPF) essentially mimics one arm of spaceborne gravitational wave detectors by shrinking the million kilometre scale armlengths down to a few tens of centimetres, giving up the sensitivity to gravitational waves, but keeping the measurement technology. The scientific objective of the LISA Pathfinder mission consists then of the first in-flight test of low frequency gravitational wave detection metrology. In this paper I will give a brief overview of the mission, focusing on scientific and technical goals.

McNamara, P.; Antonucci, F.; Armano, M.; Audley, H.; Auger, G.; Benedetti, M.; Binetruy, P.; Bogenstahl, J.; Bortoluzzi, D.; Brandt, N.; Caleno, M.; Cavalleri, A.; Congedo, G.; Cruise, M.; Danzmann, K.; De Marchi, F.; Diaz-Aguilo, M.; Diepholz, I.; Dixton, G.; Dolesi, R.; Dumbar, N.; Fauste, J.; Ferraioli, L.; Ferroni, V.; Fichter, W.; Fitzsimons, E.; Freschi, M.; García Marirrodriga, C.; Gerndt, R.; Gesa, L.; Gibert, F.; Giardini, D.; Grimani, C.; Grynagier, A.; Guzmán, F.; Harrison, I.; Heinzel, G.; Hewitson, M.; Hollington, D.; Hoyland, D.; Hueller, M.; Huesler, J.; Jennrich, O.; Jetzer, P.; Johlander, B.; Karnesis, N.; Korsakova, N.; Killow, C.; Llamas, X.; Lloro, I.; Lobo, A.; Maarschalkerweerd, R.; Madden, S.; Mance, D.; Martin, V.; Mateos, I.; Mendes, J.; Mitchell, E.; Nicolodi, D.; Nofrarias, M.; Perreur-Lloyd, M.; Plagnol, E.; Prat, P.; Ramos-Castro, J.; Reiche, J.; Romera Perez, J. A.; Robertson, D.; Rozemeijer, H.; Russano, G.; Schleicher, A.; Shaul, D.; Sopuerta, C. F.; Sumner, T. J.; Taylor, A.; Texier, D.; Trenkel, C.; Tu, H. B.; Vitale, S.; Wanner, G.; Ward, H.; Waschke, S.; Wass, P.; Wealthy, D.; Wen, S.; Weber, W.; Ziegler, T.; Zweifel, P.

2013-01-01

47

Mars Pathfinder Status at Launch  

NASA Technical Reports Server (NTRS)

The Mars Pathfinder Flight System is in final test, assembly and launch preparations at the Kennedy Space Center in Florida. Launch is scheduled for 2 Dec. 1996. The Flight System development, in particular the Entry, Descent, and Landing (EDL) system, was a major team effort involving JPL, other NASA centers and industry. This paper provides a summary Mars Pathfinder description and status at launch. In addition, a section by NASA's Langley Research Center, a key EDL contributor, is provided on their support to Mars Pathfinder. This section is included as an example of the work performed by Pathfinder team members outside JPL.

Spear, A. J.; Freeman, Delma C., Jr.; Braun, Robert D.

1996-01-01

48

Coral Reefs  

NSDL National Science Digital Library

This learning resource is a report from The Science Report about Coral Reefs.It includes Lesson Plans,extended interviews, case studies and other related resources on this topic. Some scientists are concerned that overfishing, pollution and global warming are killing parts of the world's coral reefs. Correspondent Betty Ann Bowser reports on efforts to preserve the reefs. In the second part of the series, Bowser explores the potential of reefs to provide the raw materials for life-saving drugs.

The Science Reports (;)

2005-02-01

49

The Mars Pathfinder Mission  

NASA Astrophysics Data System (ADS)

The Mars Pathfinder mission is a Discovery class mission that will place a small lander and rover on the surface of Mars on July 4, 1997. The Pathfinder flight system is a single small lander, packaged within an aeroshell and back cover with a back-pack-style cruise stage. The vehicle will be launched, fly independently to Mars, and enter the atmosphere directly on approach behind the aeroshell. The vehicle is slowed by a parachute and 3 small solid rockets before landing on inflated airbags. Petals of a small tetrahedron shaped lander open up, to right the vehicle. The lander is solar powered with batteries and will operate on the surface for up to a year, downlinking data on a high-gain antenna. Pathfinder will be the first mission to use a rover, with 3 imagers and an alpha proton X-ray spectrometer, to characterize the rocks and soils in a landing area over hundreds of square meters on Mars, which will provide a calibration point or "ground truth" for orbital remote sensing observations. The rover (includes a series of technology experiments), the instruments (including a stereo multispectral surface imager on a pop up mast and an atmospheric structure instrument-surface meteorology package) and the telemetry system will allow investigations of: the surface morphology and geology at meter scale, the petrology and geochemistry of rocks and soils, the magnetic properties of dust, soil mechanics and properties, a variety of atmospheric investigations and the rotational and orbital dynamics of Mars. Landing downstream from the mouth of a giant catastrophic outflow channel, Ares Vallis, offers the potential of identifying and analyzing a wide variety of crustal materials, from the ancient heavily cratered terrain, intermediate-aged ridged plains and reworked channel deposits, thus allowing first-order scientific investigations of the early differentiation and evolution of the crust, the development of weathering products and early environments and conditions on Mars.

Golombek, M. P.

1996-09-01

50

Cytokines Online Pathfinder Encyclopaedia  

NSDL National Science Digital Library

The Cytokines Online Pathfinder Encyclopaedia (COPE) is the brainchild of Horst Ibelgaufts of Germany's Ludwig-Maximilians-Universit't Gene Center. Part super-glossary, part general guide to the "jungles, morasses, and deserts of cytokine-land," this incredibly extensive Web site helps researchers stay on top of newly identified proteins and previously identified but recently reevaluated proteins. As of February 2003, COPE contains over 8,700 entries, which have been mercifully grouped into sub-glossaries by subject: apoptosis, cell lines, chemokines, cytokine topics, hematology, metalloproteinases virokines, viroceptors, and virulence factors.

1997-01-01

51

Environmental Variability in the Florida Keys: Impacts on Coral Reef Resilience and Health  

NASA Astrophysics Data System (ADS)

Environmental variability contributes to both mass mortality and resilience in tropical coral reef communities. We assess variations in sea surface temperature (SST) and ocean color in the Florida Keys using satellite imagery, and provide insight into how this variability is associated with locations of resilient coral communities (those unaffected by or able to recover from major events). The project tests the hypothesis that areas with historically low environmental variability promote lower levels of coral reef resilience. Time series of SST from the Advanced Very High Resolution Radiometer (AVHRR) sensors and ocean color derived quantities (e.g., turbidity and chlorophyll) from the Sea-viewing Wide Field of View Sensor (SeaWiFS) are being constructed over the entire Florida Keys region for a period of twelve and nine years, respectively. These data will be compared with historical coral cover data derived from Landsat imagery (1984-2002). Improved understanding of the causes of coral reef decline or resilience will help protect and manage these natural treasures.

Soto, I. M.; Muller-Karger, F. E.

2005-12-01

52

DECIGO and DECIGO pathfinder  

NASA Astrophysics Data System (ADS)

A space gravitational-wave antenna, DECIGO (DECI-hertz interferometer Gravitational wave Observatory), will provide fruitful insights into the universe, particularly on the formation mechanism of supermassive black holes, dark energy and the inflation of the universe. In the current pre-conceptual design, DECIGO will be comprising four interferometer units; each interferometer unit will be formed by three drag-free spacecraft with 1000 km separation. Since DECIGO will be an extremely challenging mission with high-precision formation flight with long baseline, it is important to increase the technical feasibility before its planned launch in 2027. Thus, we are planning to launch two milestone missions. DECIGO pathfinder (DPF) is the first milestone mission, and key components for DPF are being tested on ground and in orbit. In this paper, we review the conceptual design and current status of DECIGO and DPF.

Ando, Masaki; Kawamura, Seiji; Seto, Naoki; Sato, Shuichi; Nakamura, Takashi; Tsubono, Kimio; Takashima, Takeshi; Funaki, Ikkoh; Numata, Kenji; Kanda, Nobuyuki; Tanaka, Takahiro; Ioka, Kunihito; Agatsuma, Kazuhiro; Aoyanagi, Koh-suke; Arai, Koji; Araya, Akito; Asada, Hideki; Aso, Yoichi; Chiba, Takeshi; Ebisuzaki, Toshikazu; Ejiri, Yumiko; Enoki, Motohiro; Eriguchi, Yoshiharu; Fujimoto, Masa-Katsu; Fujita, Ryuichi; Fukushima, Mitsuhiro; Futamase, Toshifumi; Harada, Tomohiro; Hashimoto, Tatsuaki; Hayama, Kazuhiro; Hikida, Wataru; Himemoto, Yoshiaki; Hirabayashi, Hisashi; Hiramatsu, Takashi; Hong, Feng-Lei; Horisawa, Hideyuki; Hosokawa, Mizuhiko; Ichiki, Kiyotomo; Ikegami, Takeshi; Inoue, Kaiki T.; Ishidoshiro, Koji; Ishihara, Hideki; Ishikawa, Takehiko; Ishizaki, Hideharu; Ito, Hiroyuki; Itoh, Yousuke; Izumi, Kiwamu; Kawano, Isao; Kawashima, Nobuki; Kawazoe, Fumiko; Kishimoto, Naoko; Kiuchi, Kenta; Kobayashi, Shiho; Kohri, Kazunori; Koizumi, Hiroyuki; Kojima, Yasufumi; Kokeyama, Keiko; Kokuyama, Wataru; Kotake, Kei; Kozai, Yoshihide; Kunimori, Hiroo; Kuninaka, Hitoshi; Kuroda, Kazuaki; Maeda, Kei-ichi; Matsuhara, Hideo; Mino, Yasushi; Miyakawa, Osamu; Miyamoto, Umpei; Miyoki, Shinji; Morimoto, Mutsuko Y.; Morisawa, Toshiyuki; Moriwaki, Shigenori; Mukohyama, Shinji; Musha, Mitsuru; Nagano, Shigeo; Naito, Isao; Nakamura, Kouji; Nakamura, Masahiro; Nakano, Hiroyuki; Nakao, Kenichi; Nakasuka, Shinichi; Nakayama, Yoshinori; Nakazawa, Kazuhiro; Nishida, Erina; Nishiyama, Kazutaka; Nishizawa, Atsushi; Niwa, Yoshito; Noumi, Taiga; Obuchi, Yoshiyuki; Ohashi, Masatake; Ohishi, Naoko; Ohkawa, Masashi; Okada, Kenshi; Okada, Norio; Oohara, Kenichi; Sago, Norichika; Saijo, Motoyuki; Saito, Ryo; Sakagami, Masaaki; Sakai, Shin-ichiro; Sakata, Shihori; Sasaki, Misao; Sato, Takashi; Shibata, Masaru; Shinkai, Hisaaki; Somiya, Kentaro; Sotani, Hajime; Sugiyama, Naoshi; Suwa, Yudai; Suzuki, Rieko; Tagoshi, Hideyuki; Takahashi, Fuminobu; Takahashi, Kakeru; Takahashi, Keitaro; Takahashi, Ryutaro; Takahashi, Ryuichi; Takahashi, Tadayuki; Takahashi, Hirotaka; Akiteru, Takamori; Takano, Tadashi; Taniguchi, Keisuke; Taruya, Atsushi; Tashiro, Hiroyuki; Torii, Yasuo; Toyoshima, Morio; Tsujikawa, Shinji; Tsunesada, Yoshiki; Ueda, Akitoshi; Ueda, Ken-ichi; Utashima, Masayoshi; Wakabayashi, Yaka; Yagi, Kent; Yamakawa, Hiroshi; Yamamoto, Kazuhiro; Yamazaki, Toshitaka; Yokoyama, Jun'ichi; Yoo, Chul-Moon; Yoshida, Shijun; Yoshino, Taizoh; Sun, Ke-Xun

2010-04-01

53

Reef Relief  

NSDL National Science Digital Library

A thorough overview of coral reefs around the globe, including the threats facing them, current protection projects, and action you can take to help save reefs. "International Projects" and "The Coral Reef Ecosystem" sections are chock-full of fantastic photographs and information. Education materials may be purchased and include DVDs and teacher's guides. Many volunteer and donation opportunities. Children section includes information-filled printable coloring pages. Several different publications are available at no cost.

54

LISA Pathfinder ground testing  

NASA Astrophysics Data System (ADS)

The space-based gravitational wave observatory LISA is a joint NASA-ESA mission that requires challenging technology to ensure pure geodetic trajectories of test masses and the interferometric measurement of distance variations between them. The LISA Pathfinder mission is an ESA-launched technology demonstrator of key LISA subsystems such as spacecraft control with micronewton thrusters, test mass drag-free control, and precision laser interferometry between free-flying test masses. Ground testing of pre-flight hardware of the Gravitational Reference Sensor and Optical Metrology subsystems is currently ongoing. Studies have been carried out on very sensitive torsion pendulums that effectively reproduce a free-fall condition for the test mass within a horizontal plane in the lab, down to frequencies < 0.1 mHz. Thermal gradient induced effects, impact of gas molecules, noisy charging, surface charge patches, and other effects have been investigated and their physical models consolidated. A final upper limit on non-modeled disturbances has also been obtained within one order of magnitude of LISA requirements at 1 mHz. The interferometry system has also been extensively studied to identify noise sources and develop approaches to mitigate them. Engineering models of the optical bench, laser head and laser modulators have been interconnected and tested for functionality and noise level in closed-loop operation, demonstrating the required optical metrology sensitivity to test mass displacement. This poster presents the current status in the development and implementation of LISA Pathfinder pre-flight systems and latest results of the ongoing ground testing efforts.

Guzman, Felipe; LISA Pathfinder Team

2010-01-01

55

Launch Abort System Pathfinder Arrival  

NASA Video Gallery

The Orion Launch Abort System, or LAS, pathfinder returned home to NASA Langley on Oct. 18 on its way to NASA's Kennedy Space Center. The hardware was built at Langley and was used in preparation f...

56

Metatranscriptome Sequencing of a Reef-building Coral Elucidates Holobiont Community Gene Functions in Health and Disease  

NASA Astrophysics Data System (ADS)

The coral reefs of the Abrolhos Bank of Brazil play a vital ecological role in the health of the Southern Atlantic Ocean, but accelerating rates of disease, particularly white plague, threaten this ecosystem. Thus, an understanding of white plague disease and diagnostic tests for it are urgently needed. The coral animal is associated with a distinct microbiome, a diverse assemblage of eukaryotes, bacteria, and viruses. That these microbes have a great influence on the health of the coral has been long known, however, most of their functions are still mysterious. While recent studies have contrasted healthy and white-plague-associated communities, the causative agents and mechanisms of the disease remain unknown. We collected fragments of healthy and diseased corals, as well as post-disease skeleton, from 12 colonies of the genus Mussismilia, the major component of the reef structure in the Abrolhos bank, and increasingly, a victim of white-plague disease. Fragments were flash-frozen in situ, and prepped for culture-free high throughput sequencing of gene transcripts with the Illumina II-G. While the membership of the microbial communities associated with coral has been previously described, the a coral holobiont community's gene function has, to date, never been assayed by this powerful approach. We designed a bioinformatics pipeline to analyze the short-read data from this complex sample: identifying the functions of genes expressed in the holobiont, and describing the active community's taxonomic composition. We show that gene functions expressed by the coral's bacterial assemblage are distinct from those of the underlying skeleton, and we highlight differences in the disease samples. We find that gene markers for the dissimilatory sulfate reduction pathway more abundant in the disease state, and we further quantify this difference with qPCR. Finally, we report the abundant expression of highly repetitive transcripts in the diseased coral samples, and highlight other coral host genes whose expression differs in this disease. Our work provides a first glimpse into coral holobiont community gene function and its deviations in disease. Moreover, we hope that our bioinformatic protocol, designed to cope with the challenges of short-read transcriptomics from complex ecosystems with no close reference, will be a useful template to further understanding of the gene functions and ecological partnerships in coral reefs and other complex ecosystems.

Timberlake, S.; Helbig, T.; Fernando, S.; Penn, K.; Alm, E.; Thompson, F.; Thompson, J. R.

2012-12-01

57

Coral Reefs  

NSDL National Science Digital Library

Description of coral reef environment for high school level and higher. Page is chock full of fantastic photographs each featuring a descriptive caption. Topics discussed include ecology, symbiosis, and predator defense. The site features many different species and stages of coral from all over the globe, and also many of the fishes that are associated with coral reefs.

58

Mars Pathfinder Preliminary Results  

NASA Astrophysics Data System (ADS)

Pathfinder plays a key role as the first of the Surveyor series and as the first Discovery project to complete its mission. On July 4 the Pathfinder lands at Ares Vallis chosen as a grab-bag sample of small rocks washed down from the highland regions by the ancient catastrophic floods that once inundated the region. A multi-spectral, stereoscopic camera (IMP) was selected with the capability to discriminate rock types according to their spectral signatures between 0.4 and 1.1 microns. This range gives information on the iron mineralogies (the weathering of ferrous to ferric minerals) and some compositional information with the 0.9 micron pyroxene band. Stereo rangefinding allows contour-mapping of the surface, calculation of rock sizes, and helps with rover guidance. Operationally the camera data determines which rocks seem spectrally interesting and the stereo images allow the rover team to station the APXS against the rock for a night-long integration. The resulting data constrains the elemental composition which is then combined with the spectral data to determine the mineralogy of the rock. The study of the atmosphere is also a prime scientific goal. The ASI/MET team has instruments for measuring diurnal temperature and pressure variations as well as wind velocity. During the descent they also derive the vertical profiles of the atmosphere. IMP has three windsocks that are monitored hourly for wind signatures; looking at all three simultaneously gives the vertical wind gradient. IMP also has 8 atmospheric filters that allow the camera to image the sun directly and measure the opacity variations hourly throughout the day. At night, bright star and Phobos observations with the geology filters continue the characterization. Besides the dust opacity, three filters in the 0.94 micron water band are able to measure water vapor at large airmass factors. Finally, a series of magnets at various positions on the lander will show indications of the magnetic properties of windblown dust. This scientific station could last as long as an earth year on Mars; therefore, seasonal changes in the weather and surface can be tracked.

Smith, P. H.

1997-07-01

59

New Caledonia surface lagoon chlorophyll modeling as coastal reef area health indicator  

NASA Astrophysics Data System (ADS)

The major part of the New Caledonia (NC) lagoon was classified as UNESCO Natural Site of Humanity Patrimony. Indeed, 22 175 km2 of tropical coral lagoon area exhibit high biodiversity. The NC lagoon is semi enclosed and connected to the Coral Sea through a barrier reef segmented by narrow passes. The environment is oligotrophic, due to important flush during trade winds events, and bathymetry is highly variable. In order to predict eutrophication events, we used an extension of a 3D coupled physical-biogeochemical model recently developed on NC south western lagoon. The model is based on the Nitrogen and Carbon cycles, relating the variable stoechiometry of the elements in each biological compartment. The ecological model was developed to include an explicit description of the microbial loop. The resulting coupled model, forced by tide, wind, light, temperature and freshwater inputs, was used to calculate phytoplankton biomass, bacterial production, dissolved organic matter concentrations and nutrient recycling. Here we present results issued from the 3D coupled model ECO3M_LAGOON (biogeochemical, LOPB-IRD) and MARS3D (regional physical model, IFREMER-IRD) describing spatial and temporal interactions between water motion and biology, on larger domain including reef barrier and water exchanges through ocean-lagoon interface. To validate physical processes in the lagoon we used in situ data collected during field cruise (ValHyBio 2008, La Niña episode). Surface chlorophyll concentrations are compared with water color data from ValHyBio cruise and satellite data (MODIS/MERIS) corrected from bathymetry effects.

Fuchs, R.; Pinazo, C.; Douillet, P.; Dupouy, C.; Faure, V.; Mangin, A.

2010-10-01

60

Mars Pathfinder Landing Site Workshop  

NASA Technical Reports Server (NTRS)

The Mars Pathfinder Project is an approved Discovery-class mission that will place a lander and rover on the surface of the Red Planet in July 1997. The Mars Pathfinder Landing Site Workshop was designed to allow the Mars scientific community to provide input as to where to land Pathfinder on Mars. The workshop was attended by over 60 people from around the United States and from Europe. Over 20 landing sites were proposed at the workshop, and the scientific questions and problems concerning each were addressed. The workshop and the discussion that occured during and afterward have significantly improved the ability to select a scientifically exciting but safe landing site on Mars.

Golombek, Matthew (editor)

1994-01-01

61

Coral Reefs  

NSDL National Science Digital Library

Scientists are studying coral reefs around the world to discover the impact that warmer temperatures and increased carbon dioxide may have on the life cycle of corals. "Changing Planet" is produced in partnership with the National Science Foundation.

Learn, Nbc

2010-10-07

62

The Sonic Pathfinder: An Evaluation.  

ERIC Educational Resources Information Center

An objective evaluation of the Sonic Pathfinder, a new ultrasonic mobility aid, showed that use of the aid changes mobility in many ways. Reduced perception of environmental sounds was not reflected in performance. The majority of users traveled slowly and exhibited less than optimal strategies. (Author/CL)

Dodds, Allan G.; And Others

1984-01-01

63

Pathfinder Teaching and Learning Units.  

ERIC Educational Resources Information Center

This collection of teaching units were selected from materials developed during the Operation Pathfinder Institutes (OPI) which took place in the Pacific region between 1994 and 1999. The institutes were intended to provide upper elementary and middle school science teachers with an opportunity to develop a deeper understanding of the marine…

Hawaii Univ., Honolulu. Sea Grant Program.

64

Pathfinder's rover, airbags, & Martian terrain  

NASA Technical Reports Server (NTRS)

This is one of the first pictures taken by the camera on the Mars Pathfinder lander shortly after its touchdown at 10:07 AM Pacific Daylight Time on July 4, 1997. The small rover, named Sojourner, is seen in the foreground in its position on a solar panel of the lander. The white material on either side of the rover is part of the deflated airbag system used to absorb the shock of the landing. Between the rover and the horizon is the rock-strewn martian surface. Two hills are seen in the right distance, profiled against the light brown sky.

Pathfinder, a low-cost Discovery mission, is the first of a new fleet of spacecraft that are planned to explore Mars over the next ten years. Mars Global Surveyor, already en route, arrives at Mars on September 11 to begin a two year orbital reconnaissance of the planet's composition, topography, and climate. Additional orbiters and landers will follow every 26 months.

The Jet Propulsion Laboratory, Pasadena, CA, developed and manages the Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. JPL is an operating division of the California Institute of Technology (Caltech). The Imager for Mars Pathfinder (IMP) was developed by the University of Arizona Lunar and Planetary Laboratory under contract to JPL. Peter Smith is the Principal Investigator.

1997-01-01

65

Spacetime Metrology with LISA Pathfinder  

NASA Astrophysics Data System (ADS)

LISA is the proposed ESA-NASA gravitational wave detector in the 0.1 mHz - 0.1 Hz band. LISA Pathfinder is the down-scaled version of a single LISA arm. The arm - named Doppler link - can be treated as a differential accelerometer, measuring the relative acceleration between test masses. LISA Pathfinder - the in-flight test of the LISA instrumentation - is currently in the final implementation and planned to be launched in 2014. It will set stringent constraints on the ability to put test masses in geodesic motion to within the required differential acceleration of 3times10^{-14} m s^{-2} Hz^{-1/2} and track their relative motion to within the required differential displacement measurement noise of 9times10^{-12} m Hz^{-1/2}, around 1 mHz. Given the scientific objectives, it will carry out - for the first time with such high accuracy required for gravitational wave detection - the science of spacetime metrology, in which the Doppler link between two free-falling test masses measures the curvature. This thesis contains a novel approach to the calculation of the Doppler response to gravitational waves. It shows that the parallel transport of 4-vectors records the history of gravitational wave signals. In practice, the Doppler link is implemented with 4 bodies in LISA and 3 bodies in LISA Pathfinder. To compensate for noise sources a control logic is implemented during the measurement. The closed-loop dynamics of LISA Pathfinder can be condensed into operators acting on the motion coordinates, handling the couplings, as well as the cross-talks. The scope of system identification is the optimal calibration of the instrument. This thesis describes some data analysis procedures applied to synthetic experiments and shows the relevance of system identification for the success of LISA Pathfinder in demonstrating the principles of spacetime metrology for all future space-based missions.

Congedo, Giuseppe

2012-04-01

66

Which environmental factors predict seasonal variation in the coral health of Acropora digitifera and Acropora spicifera at Ningaloo Reef?  

PubMed

The impact of physico-chemical factors on percent coral cover and coral health was examined on a spatial basis for two dominant Acropora species, A. digitifera and A. spicifera, at Ningaloo Reef (north-western Australia) in the southeast Indian Ocean. Coral health was investigated by measuring metabolic indices (RNA/DNA ratio and protein concentration), energy levels (lipid ratio) and autotrophic indices (chlorophyll a (chl a) and zooxanthellae density) at six stations during typical seasons (austral autumn 2010 (March and April), austral winter 2010 (August)) and during an extreme La Niña event in summer 2011 (February). These indices were correlated with 15 physico-chemical factors (measured immediately following coral sampling) to identify predictors for health indices. Variations in metabolic indices (protein concentration and RNA/DNA ratio) for A. spicifera were mainly explained by nitrogen, temperature and zooplankton concentrations under typical conditions, while for A. digitifera, light as well as phytoplankton, in particular picoeukaryotes, were important, possibly due to higher energy requirement for lipid synthesis and storage in A. digitifera. Optimum metabolic values occurred for both Acropora species at 26-28°C when autotrophic indices (chl a and zooxanthellae density) were lowest. The extreme temperature during the La Niña event resulted in a shift of feeding modes, with an increased importance of water column plankton concentrations for metabolic rates of A. digitifera and light and plankton for A. spicifera. Our results suggest that impacts of high sea surface temperatures during extreme events such as La Niña may be mitigated via reduction on metabolic rates in coral host. The high water column plankton concentrations and associated low light levels resulted in a shift towards high symbiont densities, with lower metabolic rates and energy levels than the seasonal norm for the coral host. PMID:23637770

Hinrichs, Saskia; Patten, Nicole L; Feng, Ming; Strickland, Daniel; Waite, Anya M

2013-01-01

67

Coral reef restoration  

Microsoft Academic Search

Coral reefs are widely recognized for concentration of biological activity, fisheries and tourism, coastal protection, geological processes, and aesthetic wonder. A principal cause of reef damage in Florida is ships running into reefs. The other major human impact on Florida’s reefs is dredging for beach renourishment and channel maintenance. In response to chronic reef damage, federal and state agencies and

Walter C Jaap

2000-01-01

68

Coral Reef Ecosystems: Ecosystems in Crisis  

NSDL National Science Digital Library

This Science Object is the fourth of four Science Objects in the Coral Reef Ecosystems SciPack. It explores the natural and human causes of ecosystem stress. Human beings live near coral ecosystems and use them in a variety of ways. Increasing amounts of stress is brought on these ecosystems as humans continue to modify the surrounding environment as a result of population growth, technology, and consumption. Human destruction of habitats through direct harvesting, pollution, atmospheric changes, and other factors is threatening the stability and overall health of many coral reefs. Human activities may also exacerbate the impact of natural disturbances on coral reefs or compromise the ability of the reef to recover from events such as hurricanes, tsunamis, or disease. Learning Outcomes:� Describe ways in which human activities directly impact coral reef ecosystems (resource and recreational uses).� Describe ways in which human activities indirectly impact coral reef ecosystems (by changing the physical conditions, pollution, changes in the water chemistry, etc.).� Explain how human activity may decrease the reefs ability to recover from natural occurrences. � Explain the effects of increased predation or disease on a reef ecosystem.� Describe the effect of habitat loss on the reef ecosystem.� Describe the effects of weather and climate change on a healthy and weakened reef ecosystem.

National Science Teachers Association (NSTA)

2007-03-28

69

Multispectral Imaging from Mars PATHFINDER  

NASA Technical Reports Server (NTRS)

The Imager for Mars Pathfinder (IMP) was a mast-mounted instrument on the Mars Pathfinder lander which landed on Mars Ares Vallis floodplain on July 4, 1997. During the 83 sols of Mars Pathfinders landed operations, the IMP collected over 16,600 images. Multispectral images were collected using twelve narrowband filters at wavelengths between 400 and 1000 nm in the visible and near infrared (VNIR) range. The IMP provided VNIR spectra of the materials surrounding the lander including rocks, bright soils, dark soils, and atmospheric observations. During the primary mission, only a single primary rock spectral class, Gray Rock, was recognized; since then, Black Rock, has been identified. The Black Rock spectra have a stronger absorption at longer wavelengths than do Gray Rock spectra. A number of coated rocks have also been described, the Red and Maroon Rock classes, and perhaps indurated soils in the form of the Pink Rock class. A number of different soil types were also recognized with the primary ones being Bright Red Drift, Dark Soil, Brown Soil, and Disturbed Soil. Examination of spectral parameter plots indicated two trends which were interpreted as representing alteration products formed in at least two different environmental epochs of the Ares Vallis area. Subsequent analysis of the data and comparison with terrestrial analogs have supported the interpretation that the rock coatings provide evidence of earlier martian environments. However, the presence of relatively uncoated examples of the Gray and Black rock classes indicate that relatively unweathered materials can persist on the martian surface.

Ferrand, William H.; Bell, James F., III; Johnson, Jeffrey R.; Bishop, Janice L.; Morris, Richard V.

2007-01-01

70

Coral reef assessment: An index utilizing sediment constituents  

Microsoft Academic Search

Resource managers need inexpensive bioindicators to evaluate the health of coral reef ecosystems and to inform decisions on when and where to utilize more expensive assessment techniques. Following USEPA Guidelines for Evaluating Ecological Indicators, I developed the SEDCON Index (SI), a rapid-assessment protocol whichutilizes reef sediment composition to assess the integrity of coral-reef communities. Keyadvantages of this index are that

Camille A. Daniels

2005-01-01

71

Measuring coral reef community metabolism using new benthic chamber technology  

Microsoft Academic Search

Accurate measurement of coral reef community metabolism is a necessity for process monitoring and in situ experimentation on coral reef health. Traditional methodologies used for these measurements are effective but limited by location and scale constraints. We present field trial results for a new benthic chamber system called the Submersible Habitat for Analyzing Reef Quality (SHARQ). This large, portable incubation

K. K. Yates; R. B. Halley

2003-01-01

72

The Global Coral Reef Crisis: Trends and Solutions (Coral Reefs: Values, Threats, and the Marine Aquarium Trade)  

ScienceCinema

Second only to tropical rainforests, coral reefs support one of the world's most diverse natural habitats. Over 350 million individuals depend on coral reef resources for food and income. Unfortunately, the Earth is in the midst of a coral reef crisis. Anthropogenic impacts including overfishing, destructive fishing practices, sedimentation and pollution, as well as global climate change, have served to disrupt the natural processes that maintain the health of these ecosystems. Until recently, however, the global extent of the coral reef crisis was unknown. Reef Check was developed in 1996 as a volunteer, community-based monitoring protocol designed to measure the health of coral reefs on a global scale. With goals of education, monitoring, and management, Reef Check has activities in over 60 countries and territories. They have not only provided scientific evidence of the global extent of the coral reef crisis, but have provided the first community based steps to alleviate this urgent situation.

73

Using MODIS data for understanding changes in seagrass meadow health: A case study in the Great Barrier Reef (Australia).  

PubMed

Stretching more than 2000 km along the Queensland coast, the Great Barrier Reef Marine Park (GBR) shelters over 43,000 square km of seagrass meadows. Despite the status of marine protected area and World Heritage listing of the GBR, local seagrass meadows are under stress from reduced water quality levels; with reduction in the amount of light available for seagrass photosynthesis defined as the primary cause of seagrass loss throughout the GBR. Methods have been developed to map GBR plume water types by using MODIS quasi-true colour (hereafter true colour) images reclassified in function of their dominant colour. These data can be used as an interpretative tool for understanding changes in seagrass meadow health (as defined in this study by the seagrass area and abundance) at different spatial and temporal scales. We tested this method in Cleveland Bay, in the northern GBR, where substantial loss in seagrass area and biomass was detected by annual monitoring from 2007 to 2011. A strong correlation was found between bay-wide seagrass meadow area and biomass and exposure to turbid Primary (sediment-dominated) water type. There was also a strong correlation between the changes of biomass and area of individual meadows and exposure of seagrass ecosystems to Primary water type over the 5-year period. Seagrass meadows were also grouped according to the dominant species within each meadow, irrespective of location within Cleveland Bay. These consolidated community types did not correlate well with the exposure to Primary water type, and this is likely to be due to local environmental conditions with the individual meadows that comprise these groupings. This study proved that remote sensing data provide the synoptic window and repetitivity required to investigate changes in water quality conditions over time. Remote sensing data provide an opportunity to investigate the risk of marine-coastal ecosystems to light limitation due to increased water turbidity when in situ water quality data is not available or is insufficient. PMID:24709476

Petus, Caroline; Collier, Catherine; Devlin, Michelle; Rasheed, Michael; McKenna, Skye

2014-07-01

74

Project O.R.B (Operation Reef Ball): Creating Artificial Reefs, Educating the Community  

NASA Astrophysics Data System (ADS)

The Project O.R.B. (Operation Reef Ball) team at South Plantation High School's Everglades Restoration & Environmental Science Magnet Program is trying to help our ailing south Florida coral reefs by constructing, deploying, and monitoring designed artificial reefs. Students partnered with the Reef Ball Foundation, local concrete companies, state parks, Girl Scouts, Sea Scouts, local universities and environmental agencies to construct concrete reef balls, each weighing approximately 500 lbs (227 kg). Students then deployed two artificial reefs consisting of over 30 concrete reef balls in two sites previously permitted for artificial reef deployment. One artificial reef was placed approximately 1.5 miles (2.4 km) offshore of Golden Beach in Miami-Dade County with the assistance of Florida Atlantic University and their research vessel. A twin reef was deployed at the mouth of the river in Oleta River State Park in Miami. Monitoring and maintenance of the sites is ongoing with semi-annual reports due to the Reef Ball Foundation and DERM (Department of Environmental Resource Management) of Miami-Dade County. A second goal of Project O.R.B. is aligned with the Florida Local Action Strategy, the Southeast Florida Coral Reef Initiative, and the U.S. Coral Reef Task Force, all of which point out the importance of awareness and education as key components to the health of our coral reefs. Project O.R.B. team members developed and published an activity book targeting elementary school students. Outreach events incorporate cascade learning where high school students teach elementary and middle school students about various aspects of coral reefs through interactive "edu-tainment" modules. Attendees learn about water sampling, salinity, beach erosion, surface runoff, water cycle, ocean zones, anatomy of coral, human impact on corals, and characteristics of a well-designed artificial reef. Middle school students snorkel on the artificial reef to witness first-hand the success of this artificial reef. Over 3,000 students have been reached through the educational outreach endeavors of Project O.R.B. This successful STEM project models the benefits of partnerships with universities, local K-12 public schools and community conservation organizations and provides students with authentic learning experiences. Students are able to have a positive impact on their local coral reef environment, their peers and their community through this comprehensive service-learning project.

Phipps, A.

2012-04-01

75

More Efficient Path-Finding Algorithm.  

National Technical Information Service (NTIS)

In this paper, we present a new routing algorithm, which we call path-finding algorithm (PFA). It drastically reduces the possibility of temporary routing loops, which accounts for its fast convergence properties. Like other path-finding algorithms, PFA o...

J. J. Garcia-Luna-Aceves S. Murthy

2006-01-01

76

Software Aids Visualization Of Mars Pathfinder Mission  

NASA Technical Reports Server (NTRS)

Report describes Simulator for Imager for Mars Pathfinder (SIMP) computer program. SIMP generates "virtual reality" display of view through video camera on Mars lander spacecraft of Mars Pathfinder mission, along with display of pertinent textual and graphical data, for use by scientific investigators in planning sequences of activities for mission.

Weidner, Richard J.

1996-01-01

77

APEX: the Atacama Pathfinder EXperiment  

NASA Astrophysics Data System (ADS)

APEX, the Atacama Pathfinder Experiment, has been successfully commissioned and is in operation now. This novel submillimeter telescope is located at 5107 m altitude on Llano de Chajnantor in the Chilean High Andes, on what is considered one of the world's outstanding sites for submillimeter astronomy. The primary reflector with 12 m diameter has been carefully adjusted by means of holography. Its surface smoothness of 17-18 ?m makes APEX suitable for observations up to 200 ?m, through all atmospheric submm windows accessible from the ground.

Güsten, R.; Booth, R. S.; Cesarsky, C.; Menten, K. M.; Agurto, C.; Anciaux, M.; Azagra, F.; Belitsky, V.; Belloche, A.; Bergman, P.; De Breuck, C.; Comito, C.; Dumke, M.; Duran, C.; Esch, W.; Fluxa, J.; Greve, A.; Hafok, H.; Häupl, W.; Helldner, L.; Henseler, A.; Heyminck, S.; Johansson, L. E.; Kasemann, C.; Klein, B.; Korn, A.; Kreysa, E.; Kurz, R.; Lapkin, I.; Leurini, S.; Lis, D.; Lundgren, A.; Mac-Auliffe, F.; Martinez, M.; Melnick, J.; Morris, D.; Muders, D.; Nyman, L. A.; Olberg, M.; Olivares, R.; Pantaleev, M.; Patel, N.; Pausch, K.; Philipp, S. D.; Philipps, S.; Sridharan, T. K.; Polehampton, E.; Reveret, V.; Risacher, C.; Roa, M.; Sauer, P.; Schilke, P.; Santana, J.; Schneider, G.; Sepulveda, J.; Siringo, G.; Spyromilio, J.; Stenvers, K.-H.; van der Tak, F.; Torres, D.; Vanzi, L.; Vassilev, V.; Weiss, A.; Willmeroth, K.; Wunsch, A.; Wyrowski, F.

2006-07-01

78

Mapping Oyster Reef Habitats in Mobile Bay  

NASA Technical Reports Server (NTRS)

Oyster reefs around the world are declining rapidly, and although they haven t received as much attention as coral reefs, they are just as important to their local ecosystems and economies. Oyster reefs provide habitats for many species of fish, invertebrates, and crustaceans, as well as the next generations of oysters. Oysters are also harvested from many of these reefs and are an important segment of many local economies, including that of Mobile Bay, where oysters rank in the top five commercial marine species both by landed weight and by dollar value. Although the remaining Mobile Bay oyster reefs are some of the least degraded in the world, projected climate change could have dramatic effects on the health of these important ecosystems. The viability of oyster reefs depends on water depth and temperature, appropriate pH and salinity levels, and the amount of dissolved oxygen in the water. Projected increases in sea level, changes in precipitation and runoff patterns, and changes in pH resulting from increases in the amount of carbon dioxide dissolved in the oceans could all affect the viability of oyster reefs in the future. Human activities such as dredging and unsustainable harvesting practices are also adversely impacting the oyster reefs. Fortunately, several projects are already under way to help rebuild or support existing or previously existing oyster reefs. The success of these projects will depend on the local effects of climate change on the current and potential habitats and man s ability to recognize and halt unsustainable harvesting practices. As the extent and health of the reefs changes, it will have impacts on the Mobile Bay ecosystem and economy, changing the resources available to the people who live there and to the rest of the country, since Mobile Bay is an important national source of seafood. This project identified potential climate change impacts on the oyster reefs of Mobile Bay, including the possible addition of newly viable habitats in the southeastern regions of the Bay.

Bolte, Danielle

2011-01-01

79

Pathfinder on lakebed preparing for test flight  

NASA Technical Reports Server (NTRS)

Support crew prepare the Pathfinder solar-powered aircraft for a research flight on Rogers Dry Lake at NASA's Dryden Flight Research Center, Edwards, California. Pathfinder was a lightweight, solar-powered, remotely piloted flying wing aircraft used to demonstrate the use of solar power for long-duration, high-altitude flight. Its name denotes its mission as the 'Pathfinder' or first in a series of solar-powered aircraft that will be able to remain airborne for weeks or months on scientific sampling and imaging missions. Solar arrays covered most of the upper wing surface of the Pathfinder aircraft. These arrays provided up to 8,000 watts of power at high noon on a clear summer day. That power fed the aircraft's six electric motors as well as its avionics, communications, and other electrical systems. Pathfinder also had a backup battery system that could provide power for two to five hours, allowing for limited-duration flight after dark. Pathfinder flew at airspeeds of only 15 to 20 mph. Pitch control was maintained by using tiny elevators on the trailing edge of the wing while turns and yaw control were accomplished by slowing down or speeding up the motors on the outboard sections of the wing. On September 11, 1995, Pathfinder set a new altitude record for solar-powered aircraft of 50,567 feet above Edwards Air Force Base, California, on a 12-hour flight. On July 7, 1997, it set another, unofficial record of 71,500 feet at the Pacific Missile Range Facility, Kauai, Hawaii. In 1998, Pathfinder was modified into the longer-winged Pathfinder Plus configuration. (See the Pathfinder Plus photos and project description.)

1995-01-01

80

Northeast View From Pathfinder Lander  

NASA Technical Reports Server (NTRS)

This panorama of the region to the northeast of the lander was constructed to support the Sojourner Rover Team's plans to conduct an 'autonomous traverse' to explore the terrain away from the lander after science objectives in the lander vicinity had been met. The large, relatively bright surface in the foreground, about 10 meters (33 feet) from the spacecraft, in this scene is 'Baker's Bench.' The large, elongated rock left of center in the middle distance is 'Zaphod.'

This view was produced by combining 8 individual 'Superpan' scenes from the left and right eyes of the IMP camera. Each frame consists of 8 individual frames (left eye) and 7 frames (right eye) taken with different color filters that were enlarged by 500% and then co-added using Adobe Photoshop to produce, in effect, a super-resolution panchromatic frame that is sharper than an individual frame would be.

Mars Pathfinder is the second in NASA's Discovery program of low-cost spacecraft with highly focused science goals. The Jet Propulsion Laboratory, Pasadena, CA, developed and manages the Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. JPL is a division of the California Institute of Technology (Caltech). The IMP was developed by the University of Arizona Lunar and Planetary Laboratory under contract to JPL. Peter Smith is the Principal Investigator.

1997-01-01

81

Reef Education Network  

NSDL National Science Digital Library

The University of Queensland's Reef Education Network (REN) is a wonderful introduction to the amazing world of coral reefs. REN has some cool images as well as information about reef research, current problems threatening coral reefs, and the many fascinating organisms that reside within a coral reef. The Life And Times section provides a nice overview of what a reef is, while the Ask A Brain Coral section gives some introduction to biotic and abiotic relationships that occur within reefs. A unique feature is the notebook, where students can record and organize information as they navigate throughout the site.

2001-01-01

82

Vitality of reef coral populations off Key Largo, Florida: Recruitment and mortality  

Microsoft Academic Search

Recently, questions about the health of the coral reefs of the Florida Keys have been raised. Estimates of net recruitment\\u000a and mortality of reef corals on Carysfort Reef, Key Largo, Florida, suggest that these populations declined over the 14 month\\u000a interval studied. The greatest rate of change on Carysfort Reef, the most well developed reef in the northern Keys, occurred

Phillip Dustan; Coral Reef

1977-01-01

83

NOAA's Coral Reef  

NSDL National Science Digital Library

Portal to NOAA programs on coral reef research, management, protection. Online booklet describes corals, importance of reefs as habitat, value to humans, natural and human impacts. Site offers outreach and online educational materials, including lesson plans and list of things you can do. Search coral reef data and publications, find funding opportunities, review state of U.S. reefs, local and national action plans. Provides links to related sites, including coral reef photo library, international initiatives.

84

Mars pathfinder lander deployment mechanisms  

NASA Technical Reports Server (NTRS)

The Mars Pathfinder Lander employs numerous mechanisms, as well as autonomous mechanical functions, during its Entry, Descent and Landing (EDL) Sequence. This is the first US lander of its kind, since it is unguided and airbag-protected for hard landing using airbags, instead of retro rockets, to soft land. The arrival condition, location, and orientation of the Lander will only be known by the computer on the Lander. The Lander will then autonomously perform the appropriate sequence to retract the airbags, right itself, and open, such that the Lander is nearly level with no airbag material covering the solar cells. This function uses two different types of mechanisms - the Airbag Retraction Actuators and the Lander Petal Actuators - which are designed for the high torque, low temperature, dirty environment and for limited life application. The development of these actuators involved investigating low temperature lubrication, Electrical Discharge Machining (EDM) to cut gears, and gear design for limited life use.

Gillis-Smith, Greg R.

1996-01-01

85

Great Barrier Reef, Queensland, Australia  

NASA Technical Reports Server (NTRS)

This detailed view of the Great Barrier Reef, Queensland, Australia (19.5S, 149.5E) shows several small patch reefs within the overall reef system. The Great Barrier Reef, largest in the world, comprises thousands of individual reefs of great variety and are closely monitored by marine ecologists. These reefs are about 6000 years old and sit on top of much older reefs. The most rapid coral growth occurs on the landward side of the reefs.

1990-01-01

86

Mars Pathfinder airbag impact attenuation system.  

National Technical Information Service (NTIS)

The Mars Pathfinder spacecraft, scheduled for launch in November 1996, is designed to validate a low cost Entry, Descent, and Landing system and to perform scientific surface operations. The Jet Propulsion Laboratory and Sandia National Laboratories teame...

D. E. Waye J. K. Cole T. P. Rivellini

1995-01-01

87

Testing of the LISA pathfinder GRS  

NASA Astrophysics Data System (ADS)

The ESA/NASA mission,LISA (Laser Interferometric Space Antenna), will measure gravita-tional waves emitted by astronomical sources, galactic and extra-galactic, at frequencies 10-4 to 10-1 Hz. LISA is a 5-million-km arm-length interferometer whose mirrors are test masses which must be nominally free-falling to a level which does not exceed 3 · 10-15 ms-2 Hz -1/2 in acceleration. LISA Pathfinder is a technology demonstration mission which will show that the relative parasitic acceleration between two masses on one spacecraft can be lower than 3 · 10-14 ms-2 Hz -1/2 , at frequencies around 1 mHz -one order of magnitude larger than LISA's goal. At the core of the LISA Pathfinder experiment is the GRS (gravitational reference sensor), a capacitive sensor with mm gaps used to measure the position of the test mass and actuate its position in 6-degrees-of-freedom. Testing the purity of free-fall for LISA Pathfinder on-ground is achieved using a torsion pendulum which allows us to measure force disturbances at a level relevant to LISA Pathfinder. We will present the latest campaign of tests of the LISA Pathfinder GRS using the 4-test-mass torsion pendulum facility aimed at measuring force-noise sources (responsible for the parasitic acceleration) for LISA Pathfinder in its frequency band. Our GRS , is the LISA Pathfinder flight-model replica, and its testing is crucial in verifying the design and performance of the flight instrument and measuring many of the unwanted disturbances which can limit the performance of LISA and LISA pathfinder. The measurements concern the dependence of the force on the test mass position in the sensor and their electrostatic coupling, electrostatic fields due to surface-potential variations and thermal gradients.

Antonucci, Federica; Cavalleri, Antonella; Ciani, Giacomo; Congedo, Giuseppe; Dolesi, Rita; de Marchi, Fabrizio; Ferraioli, Luigi; Hueller, Mauro; Nicolodi, Daniele; Tombolato, David; Vitale, Stefano; Wass, Peter J.; Weber, William J.

88

A more efficient path-finding algorithm  

Microsoft Academic Search

Presents a new routing algorithm, which the authors call a path-finding algorithm (PFA). It drastically reduces the possibility of temporary routing loops, which accounts for its fast convergence properties. Like other path-finding algorithms, the PFA operates by specifying the second-to-last hop to each destination, in addition to the distance to the destination. A detailed proof of correctness and complexity is

Shree Murthy; J. J. Garcia-Luna-Aceves

1994-01-01

89

Pathfinder: XQuery Off the Relational Shelf  

Microsoft Academic Search

The Pathfinder project makes inventive use of relational database technology—originally developed to process data of strictly tabular shape—to construct efficient database-supported XML and XQuery pro- cessors. Pathfinder targets database engines that implement a set-oriented mode of query execution: many off-the-shelf traditional database systems make for suitable XQuery runtime environments, but a number of off-beat storage back-ends fit that bill as

Torsten Grust; Jan Rittinger; Jens Teubner

2008-01-01

90

The Mars Pathfinder ASI\\/MET Investigation  

Microsoft Academic Search

On July 4th 1997, the Mars Pathfinder spacecraft will enter the martian atmosphere, land in the Ares Vallis region, and obtain the first in-situ measurements of the atmosphere and surface since the Viking mission more than 20 years ago. In addition to a Stereo Imager and an Alpha Proton X-Ray spectrometer, the Pathfinder Lander will carry an Atmospheric Structure and

J. Schofield; D. Crisp; C. Labaw; C. Mahoney; A. Seiff; J. Murphy; J. Mihalov; G. Wilson; R. Haberle; J. Tillman; J. Barnes

1996-01-01

91

Coral Reef Ecosystems: The Living Reef  

NSDL National Science Digital Library

This Science Object is the first of four Science Objects in the Coral Reef Ecosystems SciPack. It explores the unique and diverse ecosystem of the coral reef. Coral reefs are very complex systems that create one of the largest structures on Earth of biological origins. Thousands of coral species exist in oceans worldwide. Reef-building corals remain on the same spot of the sea floor through their entire lives and have developed reproductive, feeding, and social behaviors suited to their situation. As they grow, reefs provide structural habitats for hundreds to thousands of different organisms. Learning Outcomes:� Identify coral polyp structures and describe their functions.� Describe photosynthesis in the coral environment.� Describe the evolution of a typical reef system.� Use the shape of an individual coral to identify its common name, and classify entire coral reef ecosystems based on shape and location. � Describe the process of coral polyp reproduction and growth.� Identify how the features and/or behavioral strategies of coral reef inhabitants enable them to survive in coral reef environments.

National Science Teachers Association (NSTA)

2006-11-01

92

Journey to the Reef  

NSDL National Science Digital Library

Despite their experiences with a cartoon sponge, most elementary students know little about the diverse inhabitants of coral reefs. Therefore, with vivid photography and video, diverse coral reef inhabitants were brought to life for the author's fifth-gra

Bryson, Linda

2010-01-01

93

Coral Reef Hydrogeology.  

National Technical Information Service (NTIS)

Knowledge of internal flow velocities and pore water residence time is important in understanding pore water geochemistry, nutrient fluxes at the benthic boundary, reef diagenesis, and fresh water resources in reef islands. Hydrogeologic studies of Pacifi...

R. W. Buddemeier J. A. Oberdorfer

1985-01-01

94

Planetary Coral Reef Foundation  

NSDL National Science Digital Library

The Planetary Coral Reef Foundation was founded in 1991 to address the growing crisis of destruction of coral reefs. Topics include the PCRF's mission, its research activities at sea and in space, wastewater recycling, conservation tips that can help preserve reefs, and the organization's ship, R.V. Heraclitus.

95

Journey to the Reef  

ERIC Educational Resources Information Center

Despite their experiences with a cartoon sponge, most elementary students know little about the diverse inhabitants of coral reefs. Therefore, with vivid photography and video, diverse coral reef inhabitants were brought to life for the author's fifth-grade students. Students shared their knowledge in language arts and even explored coral reefs in…

Bryson, Linda

2010-01-01

96

LISA Pathfinder Instrument Data Analysis  

NASA Technical Reports Server (NTRS)

LISA Pathfinder (LPF) is an ESA-launched demonstration mission of key technologies required for the joint NASA-ESA gravitational wave observatory in space, LISA. As part of the LPF interferometry investigations, analytic models of noise sources and corresponding noise subtraction techniques have been developed to correct for effects like the coupling of test mass jitter into displacement readout, and fluctuations of the laser frequency or optical pathlength difference. Ground testing of pre-flight hardware of the Optical Metrology subsystem is currently ongoing at the Albert Einstein Institute Hannover. In collaboration with NASA Goddard Space Flight Center, the LPF mission data analysis tool LTPDA is being used to analyze the data product of these tests. Furthermore, the noise subtraction techniques and in-flight experiment runs for noise characterization are being defined as part of the mission experiment master plan. We will present the data analysis outcome of preflight hardware ground tests and possible noise subtraction strategies for in-flight instrument operations.

Guzman, Felipe

2010-01-01

97

Reefs happen  

USGS Publications Warehouse

Corals and coral reefs confront us with a variety of paradoxes in terms of their responses to global change. The species appear evolutionarily long-lived and stable, and combinations of organisms recur and persist at levels ranging from endosymbiosis to palaeocommunity structure. The fact that these organisms and communities occupy a seemingly precarious environment near the common interface of land, sea, and air suggests that they possess powerful adaptive and acclimative mechanisms, and the special characteristics associated with their range of reproductive options, their modular (colonial) form, and their symbiotic associations provide multiple pathways for adaptation. At the same time, they are widely considered to be vulnerable to anthropogenic stresses, and to show signs of deterioration on a global scale. Interest in corals is further enhanced by their unique position with regard to the carbon cycle, with inorganic and organic carbon metabolisms that are of comparable magnitudes. The durable limestone structures they create modify the shallow-water environment, and their mineral skeletons preserve in their isotopic, chemical, and structural characteristics records of past environmental conditions. Whether as survivors, recorders, or victims, their relationship to global change is fascinating and instructive. This paper provides a general background and context for the specific papers that make up this topical issue of Global Change Biology. ?? 1996 Blackwell Science Ltd.

Kinzie, III, R. A.; Buddemeier, R. W.

1996-01-01

98

Coral Reef Adventure  

NSDL National Science Digital Library

This site from MacGillivray Freeman Films presents information about the movie "Coral Reef Adventure," as well as an assortment of links about coral reefs. In particular, the section on Learning About Reefs features a virtual dive that highlights marine life at various depths. This section also provides educational resources including a teacher's guide and learning activities. The site also includes links to many organizations that provide support for reversing the current worldwide decline in coral reef ecosystems and to finding new and sustainable solutions for managing the world's coral reefs.

Freeman, Macgillivray

99

Life and death on the coral reef: an ecological perspective on scholarly publishing in the health sciences*†  

PubMed Central

Objective: Reflecting patterns evident in past Janet Doe lectures, the 2004 address draws on the foundations of biology to provide a model that offers insights into the advent of electronic publications and choices for the future. Setting: The lecture sketches a picture of the fragile relationships found in complex ecosystems and illustrates how such interdependencies function in the environment of the coral reef. Analysis: Deriving lessons from the marine world, the lecture then shifts to a description of similarities in the realm of scholarly publishing, the impact of digital innovations in the marketplace, and the controversies and choices inherent in open access publications. Conclusions: Lessons from ecology and publishing lead to the conclusion that librarians must take action and risks in this time of dramatic environmental change.

Forsman, Rick B.

2005-01-01

100

Battery study for the Mars Environmental Survey (MESUR) Pathfinder  

NASA Technical Reports Server (NTRS)

Viewgraphs on the battery study for the Mars Environmental Survey (MESUR) Pathfinder are presented. Topics covered include: MESUR pathfinder introduction; power subsystem concept; battery technology selection; mission battery performance; cell/battery baseline design; charge methodology; and proposed testing.

Dawson, Stephen F.; Otzinger, B.; Perrone, D.; Distefano, Sal; Halpert, Gerald

1994-01-01

101

Melas Chasma: A Mars Pathfinder View of Valles Marineris.  

National Technical Information Service (NTIS)

A Mars Pathfinder landing site in Melas Chasma (Valles Marineris) would yield significant science return, but is outside present mission constraints. In Melas Chasma, Mars Pathfinder could investigate minimally altered basaltic material, sedimentary depos...

A. H. Treiman S. Murchie

1994-01-01

102

Vitality of reef coral populations off Key Largo, Florida: Recruitment and mortality  

NASA Astrophysics Data System (ADS)

Recently, questions about the health of the coral reefs of the Florida Keys have been raised. Estimates of net recruitment and mortality of reef corals on Carysfort Reef, Key Largo, Florida, suggest that these populations declined over the 14 month interval studied. The greatest rate of change on Carysfort Reef, the most well developed reef in the northern Keys, occurred in the zone of richest coverage by corals. Water pollution associated with the tremendous increase in the human population of South Florida in the last twenty years may be contributing to the reef's decline.

Dustan, Phillip

1977-01-01

103

Dioramas: Andros Coral Reef  

NSDL National Science Digital Library

In the shallow waters off the coast of Andros Island in the Caribbean, corals of all shapes and sizes form the Andros Reef, one of the largest barrier reefs in the world. Like other coral reefs, Andros was created by massive colonies of coral polyps, which are small, soft-bodied animals. These creatures have hard skeletons that form much of the structure of a coral reef. The once thriving Andros Reef is now threatened. In the past, antler-shaped elkhorn coral dominated the reef, with multiple colonies extending continuously for long stretches. Throughout the Caribbean today, this species exists primarily in isolated colonies and scientists estimate that in certain places, up to 95 percent of elkhorn coral has died. This site describes the formation of the reef along with the present problems.

104

Mars Pathfinder Mission Telescopic Observational Support  

NASA Astrophysics Data System (ADS)

Monitoring of the martian atmosphere by professional and amateur astronomers during the 1997 opposition is important for the Mars Pathfinder project because the entry, descent, and landing (EDL) sequence can be fine-tuned based on updated knowledge of the opacity and density structure of the atmosphere. The atmospheric models that have been used to develop Pathfinder EDL and surface scenarios are based on Viking Lander data, but it has been recognized that the martian atmosphere has recently been significantly colder and clearer than during the Viking missions. On the martian surface, lander and rover power depend on the insolation at the surface and radiative transfer in the atmosphere. Power is needed both to keep electronics warm during the cold martian night and for telecommunications. Hence, the amount of data that can be returned to Earth, and therefore operational scenarios, will depend on the temperature and amount of dust in the martian atmosphere. In addition, observations of Mars during Pathfinder surface operations with the landing site near the sub-Earth point would allow Pathfinder observations to be placed in a global context. Conversely, Pathfinder data will be useful in calibrating telescopic observations of Martian atmospheric opacity and temperatures. Observing time has been allocated for microwave observations of Mars from Kitt Peak and WF/PC2 imaging from the Hubble Space Telescope during the Pathfinder mission. Planning is also underway among amateur astronomers worldwide: for more information, see the MarsWatch home pages at the following URLs: http://mpfwww.jpl.nasa.gov/mpf/marswatch.html http://astrosun.tn.cornell.edu/marsnet/mnhome.html

Herkenhoff, K. E.; Golombek, M. P.; Anderson, R. C.; Bell, J. F., III

1996-09-01

105

System modelling for LISA Pathfinder  

NASA Astrophysics Data System (ADS)

LISA Pathfinder is the technology demonstrator for LISA, a space-borne gravitational waves observatory. The goal of the mission is to characterise the dynamics of the LISA Technology Package (LTP) to prove that on-board experimental conditions are compatible with the de-tection of gravitational waves. The LTP is a drag-free dynamics experiment which includes a control loop with sensors (interferometric and capacitive), actuators (capacitive actuators and thrusters), controlled disturbances (magnetic coils, heaters) and which is subject to various endogenous or exogenous noise sources such as infrared pressure or solar wind. The LTP experiment features new hardware which was never flown in space. The mission has a tight operation timeline as it is constrained to about 100 days. It is therefore vital to have efficient and precise means of investigation and diagnostics to be used during the on-orbit operations. These will be conducted using the LTP Data Analysis toolbox (LTPDA) which allows for simulation, parameter identification and various analyses (covariance analysis, state estimation) given an experimental model. The LTPDA toolbox therefore contains a series of models which are state-space representations of each component in the LTP. The State-Space Models (SSM) are objects of a state-space class within the LTPDA toolbox especially designed to address all the requirements of this tool. The user has access to a set of linear models which represent every satellite subsystem; the models are available in different forms representing 1D, 2D and 3D systems, each with settable symbolic and numeric parameters. To limit the possible errors, the models can be automatically linked to produce composite systems and closed-loops of the LTP. Finally, for the sake of completeness, accuracy and maintainability of the tool, the models contain all the physical information they mimic (i.e. variable units, description of parameters, description of inputs/outputs, etc). Models developed for this work include the fixed-point linearized equations of motion for the LTP and the linear models for sensors and actuators with their noise modelling blocks issued from the analysis of the individual actuators. The drag-free controller model includes the dis-crete delays expected in the hardware. In this work we briefly describe the software architecture, in order to concentrate then on the physical description of the models. This is supported by an overview of different user scenarios and some examples of model analysis that highlight the advantages of this high-level programming engineering toolbox for space mission data analysis and calibration.

Diaz-Aguiló, Marc; Grynagier, Adrien; Rais, Boutheina

106

Herbicides: A new threat to the Great Barrier Reef  

Microsoft Academic Search

The runoff of pesticides (insecticides, herbicides and fungicides) from agricultural lands is a key concern for the health of the iconic Great Barrier Reef, Australia. Relatively low levels of herbicide residues can reduce the productivity of marine plants and corals. However, the risk of these residues to Great Barrier Reef ecosystems has been poorly quantified due to a lack of

Stephen E. Lewis; Jon E. Brodie; Zoë T. Bainbridge; Ken W. Rohde; Aaron M. Davis; Bronwyn L. Masters; Mirjam Maughan; Michelle J. Devlin; Jochen F. Mueller; Britta Schaffelke

2009-01-01

107

Coral Reef Ecosystems  

NSDL National Science Digital Library

The Coral Reef Ecosystems SciPack explores the unique and diverse ecosystem of the coral reef. The focus is on Standards and Benchmarks related to populations and ecosystems using coral reefs and their immediate environment as an example. Because the Standards and Benchmarks present the concepts of populations and ecosystems generically, without reference to a specific ecosystem or the organisms in the system, coral reefs are used to provide the context through which concepts in a marine ecosystem are explored.In addition to comprehensive inquiry-based learning materials tied to Science Education Standards and Benchmarks, the SciPack includes the following additional components:� Pedagogical Implications section addressing common misconceptions, teaching resources and strand maps linking grade band appropriate content to standards. � Access to one-on-one support via e-mail to content "Wizards".� Final Assessment which can be used to certify mastery of the concepts.Learning Outcomes:Coral Reef Ecosystems: The Living Reef� Identify coral polyp structures and describe their functions.� Describe photosynthesis in the coral environment.� Describe the evolution of a typical reef system.� Use the shape of an individual coral to identify its common name, and classify entire coral reef ecosystems based on shape and location. � Describe the process of coral polyp reproduction and growth.� Identify how the features and/or behavioral strategies of coral reef inhabitants enable them to survive in coral reef environments.Coral Reef Ecosystems: The Abiotic Setting� Identify the characteristics of an ecosystem, and describe the interdependence between biotic and abiotic features in an ecosystem.� Describe how the following abiotic factors provide coral with the energy needed to survive and grow within their ecosystem: sunlight, water, oxygen, and carbon dioxide.� Describe the optimal environmental conditions for coral reef growth, and explain the process of coral reef development (including the role of available sunlight and calcium).� Explain how the following environmental factors might affect coral ecosystems: increase in dissolved CO2, changes in global temperatures, increase in ocean water turbidity through water pollution.Coral Reef Ecosystems: Interdependence� Identify and label key components of food chains and food webs in a coral reef ecosystem.� Describe key relationships among plants and animals in the coral reef ecosystem: predator and prey relationships, producer and consumer relationships, and symbiotic relationships (mutualism, commensalisms, parasitism).� Recognize the direction that energy travels through food chains and food webs.� Explain that materials (chemical elements) and natural resources are recycled in coral reef ecosystems and reappear in different forms.� Describe the primary ecological succession events within a typical coral reef ecosystem.Coral Reef Ecosystems: Ecosystems in Crisis� Describe ways in which human activities directly impact coral reef ecosystems (resource and recreational uses).� Describe ways in which human activities indirectly impact coral reef ecosystems (by changing the physical conditions, pollution, changes in the water chemistry, etc.).� Explain how human activity may decrease the reefs ability to recover from natural occurrences. � Explain the effects of increased predation or disease on a reef ecosystem.� Describe the effect of habitat loss on the reef ecosystem.� Describe the effects of weather and climate change on a healthy and weakened reef ecosystem.

National Science Teachers Association (NSTA)

2007-03-28

108

Mars Pathfinder mechanically pumped cooling loop  

NASA Technical Reports Server (NTRS)

A mechanically pumped single-phase cooling loop was successfully flown on the Mars Pathfinder (MPF) Spacecraft which safely landed on the Martian surface on July 4, 1997. One of the key technologies that enabled the mission to succeed was an active heat rejection system (HRS) used to cool the electronics on the spacecraft during its seven-month cruise from Earth to Mars.

Birur, G. C.

2001-01-01

109

Mars Pathfinder, Science Results, Geology and Geomorphology  

NSDL National Science Digital Library

This NASA-hosted site is a section of the Mars Pathfinder Science Results Directory with a specific emphasis on the geologic and geomorphic characteristics observed. Many photos and satellite images are available, with the option to view and download full size images. Scientific theories are offered as to the probable geomorphic agents sculpting Mars' surface.

110

Mars Pathfinder Project: Planetary Constants and Models  

NASA Technical Reports Server (NTRS)

This document provides a common set of astrodynamic constants and planetary models for use by the Mars pathfinder Project. It attempts to collect in a single reference all the quantities and models in use across the project during development and for mission operations.

Lyons, D.; Vaughn, R.

1999-01-01

111

Mechanical design of the Mars Pathfinder mission  

NASA Technical Reports Server (NTRS)

The Mars Pathfinder mission and the Sojourner rover is reported on, with emphasis on the various mission steps and the performance of the technologies involved. The mechanical design of mission hardware was critical to the success of the entry sequence and the landing operations. The various mechanisms employed are considered.

Eisen, Howard Jay; Buck, Carl W.; Gillis-Smith, Greg R.; Umland, Jeffrey W.

1997-01-01

112

Mars Pathfinder Egg Drop and Landing (EDL)  

NSDL National Science Digital Library

This is an activity about the Mars Pathfinder mission. Learners will use household materials to build a model of the lander, parachute and air bags in order to replicate the entry, descent and landing of the payload. Instructions, materials list and a diagram are included.

113

JANUS, A Proposed Pathfinder Mission to Mercury  

Microsoft Academic Search

Despite the Mariner 10 flybys and decades of ground-based observations, the planet Mercury remains the most poorly understood inner planet although it could potentially provide essential information on the evolution and origin of the solar system. JANUS, a mission proposed for the NASA Discovery Program, is an extremely fast, low cost, low risk, multiple flyby, four platform pathfinder to Mercury

S. A. Curtis; P. E. Clark; B. Giles; C. Eyerman; G. Marr; D. Winterhalter

1998-01-01

114

Modal analysis of PATHFINDER unmanned air vehicle.  

National Technical Information Service (NTIS)

An experimental modal analysis was performed on PATHFINDER, a 450-lb, 100-ft wing span, flying-wing-design aircraft powered by solar/electric motors. The aircraft was softly suspended and then excited using random input from a long-stroke shaker. Modal da...

T. G. Woehrle B. W. Costerus C. L. Lee

1994-01-01

115

Pathfinding by Peripheral Pioneer Neurons in Grasshoppers  

Microsoft Academic Search

Grasshopper neurons accurately project axons across long distances between peripheral structures and the central nervous system. Nerve-trunk pathways followed by these axons are established early in embryogenesis by pioneer neurons. Growth cones from the first pioneers navigate along a chain of cells to the CNS. The placement of these cells may constitute the initial guidance mechanism underlying long-distance pathfinding.

David Bentley; Haig Keshishian

1982-01-01

116

APECS - The Atacama Pathfinder Experiment Control System  

Microsoft Academic Search

APECS is the CORBA based, distributed control system for the new Atacama Pathfinder EXperiment (APEX) Telescope located at the Llano de Chajnantor at an altitude of 5100m in the Atacama desert in northern Chile. The telescope has been operational since August 2005 and APECS is now being used for regular science observations. APECS employs a modern, object-oriented design. Generic interfaces

D. Muders; H. Hafok; F. Wyrowski; E. Polehampton; A. Belloche; C. König; R. Schaaf; F. Schuller; J. Hatchell; F. van der Tak

2006-01-01

117

Pathfinders on Black Dance in America.  

ERIC Educational Resources Information Center

This is a compilation of 18 pathfinders (i.e., a bibliographic instruction aid) on black dance in America, prepared by graduate students in the "Information Resources in the Humanities" and the "Information Resources in the Social Sciences" classes in the Graduate School of Library and Information Science at the University of Texas at Austin. The…

Roy, Loriene, Ed.

118

Java PathFinder User Guide.  

National Technical Information Service (NTIS)

The JAVA PATHFINDER, JPF, is a translator from a subset of JAVA 1.0 to PROMELA, the programming language of the SPIN model checker. The purpose of JPF is to establish a framework for verification and debugging of JAVA programming based on model checking. ...

K. Havelund

1999-01-01

119

Coral Reef Connections  

NSDL National Science Digital Library

This resource explores Australias Great Barrier Reef, the largest structure on Earth built by living organisms. Consisting of almost 3000 individual reefs, the Great Barrier Reef houses an incredible array of biodiversity. This resource demonstrates the types of relationships among living things that have contributed to this incredible biodiversity and elaborates on some of the adaptations that have enabled species to survive and reproduce in this unique habitat.

Science NetLinks (PBS;)

2002-04-29

120

Children on the reef  

Microsoft Academic Search

Meriam children are active reef-flat collectors. We demonstrate that while foraging on the reef, children are significantly\\u000a less selective than adults. This difference and the precise nature of children’s selectivity while reef-flat collecting are\\u000a consistent with a hypothesis that both children and adults attempt to maximize their rate of return while foraging, but in\\u000a so doing they face different constraints

Douglas W. Bird; Rebecca Bliege Bird

2002-01-01

121

Coral Reef Ecosystems: The Abiotic Setting  

NSDL National Science Digital Library

This Science Object is the second of four Science Objects in the Coral Reef Ecosystems SciPack. It investigates the abiotic characteristics that affect the coral reef ecosystem. The number and kinds of organisms found along each reef depend on the physical conditions of the environment and resources available, including food, light, water quality, temperature, and other organisms living in the reef. If conditions change significantly due to changes in climate, loss of food sources, excessive predation, or loss of habitat, the health and stability of the ecosystem will be affected. Like many complex systems, coral ecosystems tend to have cyclic fluctuations around a state of rough equilibrium. In the long run, if conditions remain reasonably constant a coral ecosystem can be stable for hundreds of years. Learning Outcomes:� Identify the characteristics of an ecosystem, and describe the interdependence between biotic and abiotic features in an ecosystem.� Describe how the following abiotic factors provide coral with the energy needed to survive and grow within their ecosystem: sunlight, water, oxygen, and carbon dioxide.� Describe the optimal environmental conditions for coral reef growth, and explain the process of coral reef development (including the role of available sunlight and calcium).� Explain how the following environmental factors might affect coral ecosystems: increase in dissolved CO2, changes in global temperatures, increase in ocean water turbidity through water pollution.

National Science Teachers Association (NSTA)

2006-11-01

122

Ocean World: Coral Reefs  

NSDL National Science Digital Library

Texas A&M University presents Ocean World, a Web-based educational resource for oceanography. The feature on coral reefs has the most direct life sciences application, with easy-to-navigate sections about the coral animal, coral reefs as the rainforests of the sea, symbiosis, ecosystem services, and coral reef threats and conservation. The Web site also includes a handy hypertext glossary, an interactive quiz, and annotated links to interesting Web sites, including sites that provide real-time reef images and data. While no formal lesson plans are provided, this Web site could be easily incorporated to a related classroom module for a range of grade levels.

2007-11-20

123

Reef Education Evaluation: Environmental Knowledge and Reef Experience  

ERIC Educational Resources Information Center

Background: The Reef education evaluation: environmental knowledge and reef experience report concerns PhD research about marine education, and the investigation of learning with high school students and the effect of coral reef monitoring marine experiential education interventions. The effectiveness of classroom learning and reef trips were…

Stepath, Carl M.

2005-01-01

124

Mars Pathfinder Landing Site and Surroundings  

NASA Technical Reports Server (NTRS)

NASA's Mars Pathfinder landed on Mars on July 4, 1997, and continued operating until Sept. 27 of that year. The landing site is on an ancient flood plain of the Ares and Tiu outflow channels. The High Resolution Imaging Science Experiment (HiRISE) camera on NASA's Mars Reconnaissance Orbiter took an image on Dec. 21, 2006, that provides unprecedented detail of the geology of the region and hardware on the surface.

[figure removed for brevity, see original site] HiRISE Image This is the entire image. The crater at center bottom was unofficially named 'Big Crater' by the Pathfinder team. Its wall was visible from Pathfinder, located 3 kilometers (2 miles) to the north. The two bright features to the upper left of Big Crater are the 'Twin Peaks,' also observed by Pathfinder. The bright mound to the upper right of the Twin Peaks is 'North Knob,' seen in Pathfinder images as peaking over the horizon.

At this scale there is no obvious geologic evidence of an ancient flood. Rather, impact craters dominate the scene, attesting to an old surface. The age is probably on the order of 1.8 billion to 3.5 billion years, when the Ares and Tiu floods are estimated to have occurred. Wind-formed linear ripples and dunes are seen throughout and are concentrated within craters. Sets of polygonal ridges of enigmatic origin are seen east of the Pathfinder lander. Rocks are visible over the entire image, with heavy concentrations near fresh-looking craters. Most of them are probably blocks tossed outward by crater-forming impacts.

The complete image is centered at 19.1 degrees north latitude, 326.8 degrees east longitude. The range to the target site was 284.7 kilometers (177.9 miles). At this distance the image scale is 28.5 centimeters (11 inches) per pixel, so objects about 85 centimeters (33 inches) across are resolved. The image shown here has been map-projected to 25 centimeters (10 inches) per pixel. North is up. The image was taken at a local Mars time of 3:35 p.m., and the scene is illuminated from the west with a solar incidence angle of 52 degrees, thus the sun was about 38 degrees above the horizon. At a solar longitude of 154.0 degrees, the season on Mars is northern summer.

[figure removed for brevity, see original site] Landing Site Region This is a close-up of the area in the vicinity of the Pathfinder landing site. Major features are named. The white box outlines the area of the image, discussed next, where hardware is seen.

[figure removed for brevity, see original site] Hardware on the Surface This image shows the Pathfinder lander on the surface. Zooming in, one can discern the ramps, science deck, and portions of the airbags on the Pathfinder lander. (See next image for closer view.) The back shell and parachute are to the south, and four features that may be portions of the heat shield are identified. Two of these were visible from Pathfinder. At the time of that mission, the nearest object was provisionally identified as the back shell. However, analysis of the HiRISE image and reinterpretation of Pathfinder images, plus an improved understanding of how hardware looks on the Martian surface based on ground-level and orbital images of the Mars Exploration Rover landing sites, indicate that the glint is bright enough that it may be insulating material from inside the heat shield. The back shell and parachute were out of sight behind a ridge from Pathfinder's ground view. One of the three bright features, identified as heat shield debris, was also identified during the Pathfinder mission.

[figure removed for brevity, see original site] [figure removed for brevity, see original site] Annotated Version Unannotated Version Topographic Map of Landing Site Region Portions of the HiRISE image are overlaid onto color-coded topographic maps constructed by the U.S. Geological Survey from stereo images acquired by the Imager for Mars Pathfinder on the lander. The white feature at the

2007-01-01

125

U.S. Coral Reef Taskforce  

NSDL National Science Digital Library

Government task force created in 1998 to research, monitor and conserve coral reefs. Site includes: background on coral reef habitats; reef ecology and environmental requirements; environmental requirements of reefs; reef functions and significance; natural and human threats to reefs. Also covered are: Task Force actions; policies and partnerships; and the National Action Plan for Coral Reef Conservation.

126

Rigs-to-reefs  

Microsoft Academic Search

Rigs-to-Reefs is a catchy term for converting obsolete, nonproductive offshore oil and gas structures (platforms and rigs) to designated artificial reefs. The concept has been around for a long time; however, it is only in the last few years that broad public and private support for the idea has emerged. Government and industry have begun to look at the opportunities

Reggio; V. C. Jr

2009-01-01

127

Rivers, runoff, and reefs  

Microsoft Academic Search

The role of terrigenous sediment in controlling the occurrence of coral reef ecosystems is qualitatively understood and has been studied at local scales, but has not been systematically evaluated on a global-to-regional scale. Current concerns about degradation of reef environments and alteration of the hydrologic and sediment cycles place the issue at a focal point of multiple environmental concerns. We

C. J. McLaughlin; C. A. Smith; R. W. Buddemeier; J. D. Bartley; B. A. Maxwell

2003-01-01

128

Rivers, Runoff, and Reefs  

Microsoft Academic Search

Abstract: The role of terrigenous sediment in controlling the occurrence of coral reef ecosystems is qualitatively understood and has beenstudied at local scales, but has not been systematically evaluated on a global-to-regional scale. Current concerns about degradationof reef environments and alteration of the hydrologic and sediment cycles place the issue at a focal point of multiple environmentalconcerns. We use a

Mclaughlin Smith Buddemeier

2003-01-01

129

Great Barrier Reef  

NASA Technical Reports Server (NTRS)

A better than average view of the Great Barrier Reef was captured by SeaWiFS on a recent overpass. There is sunglint northeast of the reef and there appears to be some sort of filamentous bloom in the Capricorn Channel.

2002-01-01

130

Create a Coral Reef  

NSDL National Science Digital Library

In this hands-on OLogy activity, kids learn about coral reefs by building a diorama. Students are introduced to coral polyps and reefs and given illustrated, step-by-step directions that show how to construct a diorama containing models of a brain coral, a sea fan, a sponge, and sea anemones.

131

Life on the Reef  

NSDL National Science Digital Library

This Expeditions Web site takes an in-depth look at life on one of the world's largest barrier reefs. The site begins with a brief explanation of the expedition and what its participants were looking to find. Dive the Reef is an interactive feature that allows students to learn what separates a lagoon from a reef from a shelf. Meet the Scientists has brief biographies of the 14 team members who participated in the expedition. At the Museum is an article that discusses the selection of the barrier reef system of Andros Island as well as the AMNH's long history of Bahamian research. The Reef from Space explains how NASA's computer-enhanced pictures from space contributed to the expedition's findings. The site also includes 12 dispatches written during the expedition, which can be found in the Today from the Bahamas section.

132

ReefBase, A Global Information System on Coarl Reefs  

NSDL National Science Digital Library

ReefBase is an online information system dedicated to coral reefs. The site aims to facilitate sustainable management of coral reefs and related coastal/marine environments. Included are data and information on the location, status, threats, monitoring, legislation, and management of coral reefs in 131 countries, extensive data on coral bleaching, a state-of-the-art online mapping-system that allows custom-made maps of coral reefs and related datasets, and an extensive bibliography of publications.

Reefbase

133

VEGA Pathfinder navigation for Giotto Halley encounter  

NASA Technical Reports Server (NTRS)

Results of the VEGA Pathfinder concept which was used to successfully target the European Space Agnecy's Giotto spacecraft to a 600 km encounter with the comet Halley are presented. Pathfinder was an international cooperative navigation activity involving USSR, European and U.S. space agencies. The final Giotto targeting maneuver was based on a comet location determined from optical data acquired by the earlier arriving Soviet VEGA spacecraft. Inertial pointing angles extracted from optical images of the comet nucleus were combined with a precise estimate of the VEGA encounter orbits determined using VLBI data acquired by NASA's Deep Space Network to predict the location of Halley at Giotto encounter. This article describes the VLBI techniques used to determine the VEGA orbits and shows that the insensitivity of the VLBI data strategy to unmodeled dynamic error sources resulted in estimates of the VEGA orbits with an accuracy of 50 km.

Ellis, J.; Mcelrath, T. P.

1986-01-01

134

Optical payload for the STARE pathfinder mission  

NASA Astrophysics Data System (ADS)

The Space-based Telescopes for Actionable Refinement of Ephemeris (STARE) program will collect the information needed to help satellite operators avoid collisions in space by using a network of nano-satellites to determine more accurate trajectories for selected space objects orbiting the Earth. In the first phase of the STARE program, two pathfinder cube-satellites (CubeSats) equipped with an optical imaging payload are being developed and deployed to demonstrate the main elements of the STARE concept. In this paper, we first give an overview of the STARE program. We then describe the details of the optical imaging payload for the STARE pathfinder CubeSats, including the optical design and the sensor characterization. Finally, we discuss the track detection algorithm that will be used on the images acquired by the payload.

Simms, Lance M.; Riot, Vincent; de Vries, Willem; Olivier, Scot S.; Pertica, Alex; Bauman, Brian J.; Phillion, Don; Nikolaev, Sergei

2011-05-01

135

Parameter estimation in LISA Pathfinder operational exercises  

NASA Astrophysics Data System (ADS)

The LISA Pathfinder data analysis team has been developing in the last years the infrastructure and methods required to run the mission during flight operations. These are gathered in the LTPDA toolbox, an object oriented MATLAB toolbox that allows all the data analysis functionalities for the mission, while storing the history of all operations performed to the data, thus easing traceability and reproducibility of the analysis. The parameter estimation methods in the toolbox have been applied recently to data sets generated with the OSE (Off-line Simulations Environment), a detailed LISA Pathfinder non-linear simulator that will serve as a reference simulator during mission operations. These simulations, so called operational exercises, are the last verification step before translating these experiments into tele-command sequences for the spacecraft, producing therefore very relevant datasets to test our data analysis methods. In this contribution we report the results obtained with three different parameter estimation methods during one of these operational exercises.

Nofrarias, M.; Ferraioli, L.; Congedo, G.; Hueller, M.; Armano, M.; Diaz-Aguiló, M.; Grynagier, A.; Hewitson, M.; Vitale, S.

2012-06-01

136

Impact of sea-level rise and coral mortality on the wave dynamics and wave forces on barrier reefs.  

PubMed

A one-dimensional wave model was used to investigate the reef top wave dynamics across a large suite of idealized reef-lagoon profiles, representing barrier coral reef systems under different sea-level rise (SLR) scenarios. The modeling shows that the impacts of SLR vary spatially and are strongly influenced by the bathymetry of the reef and coral type. A complex response occurs for the wave orbital velocity and forces on corals, such that the changes in the wave dynamics vary reef by reef. Different wave loading regimes on massive and branching corals also leads to contrasting impacts from SLR. For many reef bathymetries, wave orbital velocities increase with SLR and cyclonic wave forces are reduced for certain coral species. These changes may be beneficial to coral health and colony resilience and imply that predicting SLR impacts on coral reefs requires careful consideration of the reef bathymetry and the mix of coral species. PMID:24768171

Baldock, T E; Golshani, A; Callaghan, D P; Saunders, M I; Mumby, P J

2014-06-15

137

Pathfinder-Plus aircraft in flight  

NASA Technical Reports Server (NTRS)

The Pathfinder-Plus solar-powered aircraft is shown taking off from a runway, then flying at low altitude over the ocean. The vehicle, which looks like a flying ruler, operates at low airspeed. Among the missions proposed for a solar-powered aircraft are communications relay, atmospheric studies, pipeline monitoring and gas leak detection, environmental monitoring using thermal and radar images, and disaster relief and monitoring.

1998-01-01

138

ReefBase: A Global Information System on Coral Reefs  

NSDL National Science Digital Library

ReefBase, a comprehensive Web portal for information on coral reefs, is presented by the World Fish Center based in Malaysia. Intended for use by reef managers, scientists, and the general public, ReefBase aims to "facilitate better understanding of the interdependence between humans and coral reefs, in order to benefit management and conservation efforts of these important resources." ReefBase provides information on coastal and marine resources, coral reef threats, resource management practices, maps and photos, references, and more. Users can quickly search for information organized by country or territory using a convenient dropdown menu. ReefBase is frequently updated; one recent addition is a status report for coral reefs of the southwestern Indian Ocean.

Noordeloos, Machiel E.; Oliver, J.

139

Australia's Great Barrier Reef  

NASA Technical Reports Server (NTRS)

The Great Barrier Reef extends for 2,000 kilometers along the northeastern coast of Australia. It is not a single reef, but a vast maze of reefs, passages, and coral cays (islands that are part of the reef). This nadir true-color image was acquired by the MISR instrument on August 26, 2000 (Terra orbit 3679), and shows part of the southern portion of the reef adjacent to the central Queensland coast. The width of the MISR swath is approximately 380 kilometers, with the reef clearly visible up to approximately 200 kilometers from the coast. It may be difficult to see the myriad details in the browse image, but if you retrieve the higher resolution version, a zoomed display reveals the spectacular structure of the many reefs.

The more northerly coastal area in this image shows the vast extent of sugar cane cultivation, this being the largest sugar producing area in Australia, centered on the city of Mackay. Other industries in the area include coal, cattle, dairying, timber, grain, seafood, and fruit. The large island off the most northerly part of the coast visible in this image is Whitsunday Island, with smaller islands and reefs extending southeast, parallel to the coast. These include some of the better known resort islands such as Hayman, Lindeman, Hamilton, and Brampton Islands.

Further south, just inland of the small semicircular bay near the right of the image, is Rockhampton, the largest city along the central Queensland coast, and the regional center for much of central Queensland. Rockhampton is just north of the Tropic of Capricorn. Its hinterland is a rich pastoral, agricultural, and mining region.

MISR was built and is managed by NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Office of Earth Science, Washington, DC. The Terra satellite is managed by NASA's Goddard Space Flight Center, Greenbelt, MD. JPL is a division of the California Institute of Technology.

2001-01-01

140

Revisiting coral reef connectivity  

Microsoft Academic Search

A large river plume generated by anomalous precipitation and oceanic circulation associated with Hurricane Mitch was detected off Honduras in October 1998 using SeaWiFS ocean color images. This event provides the background for analyzing connectivity between coral reefs and land in the Meso-American reef system. We discuss the potential implications of such short-term events for disease propagation and nutrification, and

S. Andréfouët; P. Mumby; M. McField; C. Hu; F. Muller-Karger

2002-01-01

141

Amazing Reef: Moviemaker  

NSDL National Science Digital Library

In this movie-making interactive, learners can make an animated film about life on a coral reef. Learners choose an exciting story, cast colorful characters, and animate the movie themselves. They then add music and titles to complete the movie. Learners can even keep the movie by downloading it to their own computer. Learners can make up to four movies relating to survival, symbiosis, habitat, and predator/prey relationships in the Philippines Tropical Coral Reef.

Aquarium, Shedd; Educational Web Adventures (Eduweb)

2006-01-01

142

Spatial distribution of epibenthic molluscs on a sandstone reef in the Northeast of Brazil.  

PubMed

The present study investigated the distribution and abundance of epibenthic molluscs and their feeding habits associated to substrate features (coverage and rugosity) in a sandstone reef system in the Northeast of Brazil. Rugosity, low coral cover and high coverage of zoanthids and fleshy alga were the variables that influenced a low richness and high abundance of a few molluscan species in the reef habitat. The most abundant species were generalist carnivores, probably associated to a lesser offer and variability of resources in this type of reef system, when compared to the coral reefs. The results found in this study could reflect a normal characteristic of the molluscan community distribution in sandstone reefs, with low coral cover, or could indicate a degradation state of this habitat if it is compared to coral reefs, once that the significantly high coverage of fleshy alga has been recognized as a negative indicator of reef ecosystems health. PMID:22735136

Martinez, A S; Mendes, L F; Leite, T S

2012-05-01

143

Pathfinders for Finding Information on Native Americans with Disabilities.  

ERIC Educational Resources Information Center

This bibliography offers strategies for locating information on selected topics of concern to those working with Native Americans with disabilities. The strategies are arranged in a format called a pathfinder. Each pathfinder follows a similar format, beginning with a brief overview of the topic, followed with an annotated bibliography, and…

Roy, Loriene, Comp.

144

Pathfinder Instruments for Cloud and Aerosol Spaceborne Observations (PICASSO)  

NASA Technical Reports Server (NTRS)

This paper will describe the planned 3-year Pathfinder Instruments for Cloud and Aerosol Spaceborne Observations (PICASSO) mission, its instrumentation and implementation. It will use LITE and other data, plus analyses, to show the feasibility of such a mission. PICASSO is being proposed for NASA's Earth System Science Pathfinder (ESSP) program with launch predicted in 2003.

McCormick, M. Patrick; Winker, David M.

1998-01-01

145

An overview of Miocene reefs  

SciTech Connect

Miocene reefs lived approximately within the latitudes of 27{degree}S to 48{degree}N compared with 25{degree}S and 32{degree}N for Holocene reefs. This expansion of reef-growing environments was the result of warm Miocene climates, aided by a eustatic sea level rise and tectonic styles that provided numerous foundations for reef development. The majority of Miocene reefs are found in three main areas: (1) Southeast Asia and the western Pacific, (2) the Mediterranean-Middle East, and (3) Middle America and the Caribbean. These regions, with their distinctive suites of coral and foramineral species, formed three biological provinces; respectively, they are the Indo-Pacific, Tethyan, and Western Atlantic provinces. Miocene reefs in Southeast Asia occur in several foreland basins as patch reef complexes on paleohighs and as barrier reefs in back-arc basins. Those reefs in the Mediterranean occur as fringing reefs, middle-shelf patch reefs, or as barrier reefs on the edges of tectonic blocks associated with Alpine thrust belts. Most reefs in the Caribbean grew on isolated open-ocean highs of volcanic origin. Miocene reefs display a diversity of framework types: (1) coral-encrusting, red algal boundstones with diverse coral faunas, (2) branching coral-encrusting, red algal boundstones with a limited Poritid fauna, (3) encrusting red algal boundstones. Barrier reef systems are especially rich in encrusting red algae and robust corals; grainstones are common as interbedded sediment. Patch reef complexes, however, display muddy carbonate textures, may have less diverse coral faunas, and commonly have larger foraminifera. The global distribution of Miocene reefs is important because (1) it provides insight into a paleoclimatic view of the earth during a major greenhouse stage and (2) Miocene buildups, such as the Arun (EUR of 14 tcf) and Bima fields (EUR of about 100 MMBO), are exploration targets.

Jordan, C.F. Jr. (Mobil Research and Development Corp., Dallas, TX (USA)); Colgan, M.W. (College of Charleston, SC (USA)); Frost, S.H. (Unocal, Los Angeles, CA (USA)); Glenn, E.C. (Phillips Petroleum, Bartlesville, OK (USA)); Bosence, D. (Royal Holloway and Bedford New College, Egham (England)); Esteban, M. (ERICO Petroleum Information Ltd., London (England))

1990-05-01

146

Mars Pathfinder Wheel Abrasion Experiment Ground Test  

NASA Technical Reports Server (NTRS)

The National Aeronautics and Space Administration (NASA) sent a mission to the martian surface, called Mars Pathfinder. The mission payload consisted of a lander and a rover. The primary purpose of the mission was demonstrating a novel entry, descent, and landing method that included a heat shield, a parachute, rockets, and a cocoon of giant air bags. Once on the surface, the spacecraft returned temperature measurements near the Martian surface, atmosphere pressure, wind speed measurements, and images from the lander and rover. The rover obtained 16 elemental measurements of rocks and soils, performed soil-mechanics, atmospheric sedimentation measurements, and soil abrasiveness measurements.

Keith, Theo G., Jr.; Siebert, Mark W.

1998-01-01

147

The Barrier Reef sediment apron: Tobacco Reef, Belize  

Microsoft Academic Search

Sedimentological and biological surveys of the back-reef sediment apron of Tobacco Reef, a continuous segment of the Belizean Barrier Reef, reveal five distinct biogeological zones: (1) coralline-coral-Dictyota pavement, (2) Turbinaria-Sargassum rubble, (3) Laurencia-Acanthophora sand and gravel, (4) bare sand and 95 Thalassia sand. These zones parallel the entire 9-km reef. The distribution of these zones is related to the spatial

Ian G. Macintyre; Richard R. Graus; Peter N. Reinthal; Mark M. Littler; Diane S. Littler

1987-01-01

148

Carbonate Production by Coral Reefs.  

National Technical Information Service (NTIS)

In the paper, the authors first create hypothetical models of coral reefs, based upon carbonate production estimates for individual organisms; then they compare the models with what is known about real reef communities and their geologic histories. The di...

K. E. Chave S. V. Smith K. J. Roy

1971-01-01

149

Impact Of Coral Structures On Wave Directional Spreading Across A Shallow Reef Flat - Lizard Island, Northern Great Barrier Reef  

NASA Astrophysics Data System (ADS)

Coral reef hydrodynamics operate at several and overlapping spatial-temporal scales. Waves have the most important forcing function on shallow (< 5 m) reefs as they drive most ecological and biogeochemical processes by exerting direct physical stress, directly mixing water (temperature and nutrients) and transporting sediments, nutrients and plankton. Reef flats are very effective at dissipating wave energy and providing an important ecosystem service by protecting highly valued shorelines. The effectiveness of reef flats to dissipate wave energy is related to the extreme hydraulic roughness of the benthos and substrate composition. Hydraulic roughness is usually obtained empirically from frictional-dissipation calculations, as detailed field measurements of bottom roughness (e.g. chain-method or profile gauges) is a very labour and time-consuming task. In this study we measured the impact of coral structures on wave directional spreading. Field data was collected during October 2012 across a reef flat on Lizard Island, northern Great Barrier Reef. Wave surface levels were measured using an array of self-logging pressure sensors. A rapid in situ close-range photogrammetric method was used to create a high-resolution (0.5 cm) image mosaic and digital elevation model. Individual coral heads were extracted from these datasets using geo-morphometric and object-based image analysis techniques. Wave propagation was modelled using a modified version of the SWAN model which includes the measured coral structures in 2m by 1m cells across the reef. The approach followed a cylinder drag approach, neglecting skin friction and inertial components. Testing against field data included bed skin friction. Our results show, for the first time, how the variability of the reef benthos structures affects wave dissipation across a shallow reef flat. This has important implications globally for coral reefs, due to the large extent of their area occupied by reef flats, particularly, as global-scale degradation in coral reef health is causing a lowering of reef carbonate production that might lead to a decrease in reef structure and roughness.

Leon, J. X.; Baldock, T.; Callaghan, D. P.; Hoegh-guldberg, O.; Mumby, P.; Phinn, S. R.; Roelfsema, C. M.; Saunders, M. I.

2013-12-01

150

The Australian SKA Pathfinder (ASKAP) software architecture  

NASA Astrophysics Data System (ADS)

The Australian SKA Pathfinder (ASKAP) is a 1% Square Kilometre Array (SKA) pathfinder radio telescope, comprising of 36 12-metre diameter reflector antennas, each with a Focal Plane Array consisting of approximately 100 dualpolarised elements operating at centimetre wavelengths and yielding a wide field-of-view (FOV) on the sky of about 30 square degrees. ASKAP is currently under construction and will be located in the remote radio-quiet desert Midwest region of Western Australia. It is expected to be fully operational in 2013. Key challenges include near real-time processing of large amount of data (~ 4 GB/s), control and monitoring of widely distributed devices (approx. 150,000 monitoring I/O points) and remote semi-automated operations. After evaluating several software technologies we have decided to use the EPICS framework for the Telescope Operating System and the Internet Communications Engine (ICE) middleware for the high-level service bus. This paper presents a summary of the overall ASKAP software architecture, as well as describing how EPICS and ICE technologies fit in the control software design.

Guzman, Juan C.; Humphreys, Ben

2010-07-01

151

Overhead View of Pathfinder Landing Site  

NASA Technical Reports Server (NTRS)

Planimetric (overhead view) map of the landing site, to a distance of 20 meters from the spacecraft. North is at the top in this and Plates 3-5. To produce this map, images were geometrically projected onto an assumed mean surface representing the ground. Features above the ground plane (primarily rocks) therefore appear displaced radially outward; the amount of distortion increases systematically with distance. The upper surfaces of the lander and rover also appear enlarged and displaced because of their height. Primary grid (white) is based on the Landing Site Cartographic (LSC) coordinate system, defined with X eastward, Y north, and Z up, and origin located at the mean ground surface immediately beneath the deployed position of the IMP camera gimbal center. Secondary ticks (cyan) are based on the Mars local level (LL) frame, which has X north, Y east, Z down, with origin in the center of the lander baseplate. Rover positions (including APXS measurements) are commonly reported in the LL frame. Yellow grid shows polar coordinates based on the LSC system. Cartographic image processing by U.S. Geological Survey.

NOTE: original caption as published in Science Magazine

Mars Pathfinder is the second in NASA's Discovery program of low-cost spacecraft with highly focused science goals. The Jet Propulsion Laboratory, Pasadena, CA, developed and manages the Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. JPL is a division of the California Institute of Technology (Caltech).

1997-01-01

152

Mars Pathfinder flight system integration and test.  

NASA Astrophysics Data System (ADS)

This paper describes the system integration and test experiences, problems and lessons learned during the assembly, test and launch operations (ATLO) phase of the Mars Pathfinder flight system scheduled to land on the surface of Mars on July 4, 1997. The Mars Pathfinder spacecraft consists of three spacecraft systems: cruise stage, entry vehicle and lander. The cruise stage carries the entry and lander vehicles to Mars and is jettisoned prior to entry. The entry vehicle, including aeroshell, parachute and deceleration rockets, protects the lander during the direct entry and reduces its velocity from 7.6 to 0 km/s in stages during the 5 min entry sequence. The lander's touchdown is softened by airbags which are retracted once stopped on the surface. The lander then uprights itself, opens up fully and begins surface operations including deploying its camera and rover. This paper overviews the system design and the results of the system integration and test activities, including the entry, descent and landing subsystem elements. System test experiences including science instruments, the microrover, Sojourner, and software are discussed. The final qualification of the entry, descent and landing subsystems during this period is also discussed.

Muirhead, B. K.

153

Coral reef hydrogeology  

SciTech Connect

Knowledge of internal flow velocities and pore water residence time is important in understanding pore water geochemistry, nutrient fluxes at the benthic boundary, reef diagenesis, and fresh water resources in reef islands. Hydrogeologic studies of Pacific and Indian Ocean reef and atoll islands indicate a dual aquifer systems; the major Pleistocene aquifer has hydraulic conductivities on the order of 1000 m/d, while the overlying Holocene aquifer of unconsolidated sediments is at least an order of magnitude less permeable. The high permeability in the Pleistocene formation is the result of large voids, both constructional and from subaerial solution during low stands of the sea. Wind, wave and tide induced head differences ranging from a few centimeters to several tens of centimeters provide the driving force for internal flow. Pore water residence times and geochemistry will vary greatly, depending on whether the water is in a major flow channel or in more restricted pores. Studies of both submerged reefs and atoll islands give bulk pore water residence times on the order of months to a few years. Chemical analyses of pore water indicate that both carbonate solution and precipitation are taking place, which will alter porosity and permeability with time. The dual aquifer model also suggests that the Ghyben-Herzberg lens approach to reef island fresh water resources is inaccurate and can lead to a gross overestimation of the potable resource. 18 refs., 5 figs.

Buddemeier, R.W.; Oberdorfer, J.A.

1985-05-21

154

Postglacial Fringing-Reef to Barrier-Reef conversion on Tahiti links Darwin's reef types  

PubMed Central

In 1842 Charles Darwin claimed that vertical growth on a subsiding foundation caused fringing reefs to transform into barrier reefs then atolls. Yet historically no transition between reef types has been discovered and they are widely considered to develop independently from antecedent foundations during glacio-eustatic sea-level rise. Here we reconstruct reef development from cores recovered by IODP Expedition 310 to Tahiti, and show that a fringing reef retreated upslope during postglacial sea-level rise and transformed into a barrier reef when it encountered a Pleistocene reef-flat platform. The reef became stranded on the platform edge, creating a lagoon that isolated it from coastal sediment and facilitated a switch to a faster-growing coral assemblage dominated by acroporids. The switch increased the reef's accretion rate, allowing it to keep pace with rising sea level, and transform into a barrier reef. This retreat mechanism not only links Darwin's reef types, but explains the re-occupation of reefs during Pleistocene glacio-eustacy.

Blanchon, Paul; Granados-Corea, Marian; Abbey, Elizabeth; Braga, Juan C.; Braithwaite, Colin; Kennedy, David M.; Spencer, Tom; Webster, Jody M.; Woodroffe, Colin D.

2014-01-01

155

Postglacial Fringing-Reef to Barrier-Reef conversion on Tahiti links Darwin's reef types.  

PubMed

In 1842 Charles Darwin claimed that vertical growth on a subsiding foundation caused fringing reefs to transform into barrier reefs then atolls. Yet historically no transition between reef types has been discovered and they are widely considered to develop independently from antecedent foundations during glacio-eustatic sea-level rise. Here we reconstruct reef development from cores recovered by IODP Expedition 310 to Tahiti, and show that a fringing reef retreated upslope during postglacial sea-level rise and transformed into a barrier reef when it encountered a Pleistocene reef-flat platform. The reef became stranded on the platform edge, creating a lagoon that isolated it from coastal sediment and facilitated a switch to a faster-growing coral assemblage dominated by acroporids. The switch increased the reef's accretion rate, allowing it to keep pace with rising sea level, and transform into a barrier reef. This retreat mechanism not only links Darwin's reef types, but explains the re-occupation of reefs during Pleistocene glacio-eustacy. PMID:24845540

Blanchon, Paul; Granados-Corea, Marian; Abbey, Elizabeth; Braga, Juan C; Braithwaite, Colin; Kennedy, David M; Spencer, Tom; Webster, Jody M; Woodroffe, Colin D

2014-01-01

156

Big Crater as Viewed by Pathfinder Lander  

NASA Technical Reports Server (NTRS)

The 'Big Crater' is actually a relatively small Martian crater to the southeast of the Mars Pathfinder landing site. It is 1500 meters (4900 feet) in diameter, or about the same size as Meteor Crater in Arizona. Superimposed on the rim of Big Crater (the central part of the rim as seen here) is a smaller crater nicknamed 'Rimshot Crater.' The distance to this smaller crater, and the nearest portion of the rim of Big Crater, is 2200 meters (7200 feet). To the right of Big Crater, south from the spacecraft, almost lost in the atmospheric dust 'haze,' is the large streamlined mountain nicknamed 'Far Knob.' This mountain is over 450 meters (1480 feet) tall, and is over 30 kilometers (19 miles) from the spacecraft. Another, smaller and closer knob, nicknamed 'Southeast Knob' can be seen as a triangular peak to the left of the flanks of the Big Crater rim. This knob is 21 kilometers (13 miles) southeast from the spacecraft.

The larger features visible in this scene - Big Crater, Far Knob, and Southeast Knob - were discovered on the first panoramas taken by the IMP camera on the 4th of July, 1997, and subsequently identified in Viking Orbiter images taken over 20 years ago. The scene includes rocky ridges and swales or 'hummocks' of flood debris that range from a few tens of meters away from the lander to the distance of South Twin Peak. The largest rock in the nearfield, just left of center in the foreground, nicknamed 'Otter', is about 1.5 meters (4.9 feet) long and 10 meters (33 feet) from the spacecraft.

This view of Big Crater was produced by combining 6 individual 'Superpan' scenes from the left and right eyes of the IMP camera. Each frame consists of 8 individual frames (left eye) and 7 frames (right eye) taken with different color filters that were enlarged by 500% and then co-added using Adobe Photoshop to produce, in effect, a super-resolution panchromatic frame that is sharper than an individual frame would be.

Mars Pathfinder is the second in NASA's Discovery program of low-cost spacecraft with highly focused science goals. The Jet Propulsion Laboratory, Pasadena, CA, developed and manages the Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. JPL is a division of the California Institute of Technology (Caltech). The IMP was developed by the University of Arizona Lunar and Planetary Laboratory under contract to JPL. Peter Smith is the Principal Investigator.

1997-01-01

157

Gray's Reef Research  

NSDL National Science Digital Library

Provides a sampling of research projects conducted at the Gray's Reef National Marine Sanctuary off Georgia's Sapelo Island. Projects range from geology to trawling impacts on the seafloor, estimating fish populations by video transect, Sanctuary monitoring using data buoys, sidescan sonar and other technologies. Examples of current projects: conducting a study on the movement patterns of fish in the area; efforts to understand the roles of "choices" fishes might make in their behaviors, and its impact on diversity of species found in reef fish communities and a study designed to inventory the invertebrates and fish communities and analyze how those communities are impacted by fishing activities. Appropriate for grades 9 and up.

158

Coral reef resilience through biodiversity  

USGS Publications Warehouse

Irrefutable evidence of coral reef degradation worldwide and increasing pressure from rising seawater temperatures and ocean acidification associated with climate change have led to a focus on reef resilience and a call to “manage” coral reefs for resilience. Ideally, global action to reduce emission of carbon dioxide and other greenhouse gases will be accompanied by local action. Effective management requires reduction of local stressors, identification of the characteristics of resilient reefs, and design of marine protected area networks that include potentially resilient reefs. Future research is needed on how stressors interact, on how climate change will affect corals, fish, and other reef organisms as well as overall biodiversity, and on basic ecological processes such as connectivity. Not all reef species and reefs will respond similarly to local and global stressors. Because reef-building corals and other organisms have some potential to adapt to environmental changes, coral reefs will likely persist in spite of the unprecedented combination of stressors currently affecting them. The biodiversity of coral reefs is the basis for their remarkable beauty and for the benefits they provide to society. The extraordinary complexity of these ecosystems makes it both more difficult to predict their future and more likely they will have a future.

Rogers, Caroline S.

2013-01-01

159

The evolution of reef communities  

SciTech Connect

This book discusses the composition, structure, occurrence, and changes in reefs during the past 2 billion years. It emphasizes the functional roles of major groups (guilds) of reef-building, reef-destroying, and reed-dwelling organisms in the most complex of all marine communities. A structural model, based on modern reef guilds, is developed. Then the functional roles of each major reef-building higher biologic taxon (algae, sponges, coral, etc.) is determined, and, on this basis, each such taxon is assigned to a reef community guild. Next, the authors traces the geologic history and guild assignment of each major taxon through geologic time. The final chapter establishes a succession of ten major reef community types, and considers their extinction and recovery in the light of modern theories of cosmic and earthly events.

Fagerstrom, J.A.

1987-01-01

160

Modal analysis of PATHFINDER unmanned air vehicle  

SciTech Connect

An experimental modal analysis was performed on PATHFINDER, a 450-lb, 100-ft wing span, flying-wing-design aircraft powered by solar/electric motors. The aircraft was softly suspended and then excited using random input from a long-stroke shaker. Modal data was taken from 92 measurement locations on the aircraft using newly designed, lightweight, tri-axial accelerometers. A conventional PC-based data acquisition system provided data handling. Modal parameters were calculated, and animated mode shapes were produced using SMS STARStruct{trademark} Modal Analysis System software. The modal parameters will be used for validation of finite element models, optimum placement of onboard accelerometers during flight testing, and vibration isolation design of sensor platforms.

Woehrle, T.G.; Costerus, B.W.; Lee, C.L.

1994-10-19

161

The Imager for Mars Pathfinder Insurance Pan  

NASA Technical Reports Server (NTRS)

The Imager for Mars Pathfinder (IMP) obtained a full panorama of the Sagan Memorial Station landing site on Sol 2, before the IMP mast was deployed. The images in this panorama were taken in 4 filters (including stereo) and losslessly compressed to provide a high-quality multispectral survey of the landing site even if the IMP mast did not successfully deploy; this data set was therefore called the Insurance Pan. It was completed late in the afternoon of Sol 2, just before the IMP mast was (successfully) deployed. The data were stored in memory and returned to Earth after it became clear that downlink rates were higher than expected. The Insurance Pan horizontal (azimuth) coverage is nearly complete, with gaps caused by pointing errors and data packet losses. Stereo data were acquired in the blue (445 nm) filter, as well as right-eye green (531 nm), orange (600 nm), and near-infrared (752 nm) data.

Herkenhoff, K. E.; Johnson, J. R.; Weller, L. A.

2003-01-01

162

Java PathFinder User Guide  

NASA Technical Reports Server (NTRS)

The JAVA PATHFINDER, JPF, is a translator from a subset of JAVA 1.0 to PROMELA, the programming language of the SPIN model checker. The purpose of JPF is to establish a framework for verification and debugging of JAVA programming based on model checking. The main goal is to automate program verification such that a programmer can apply it in the daily work without the need for a specialist to manually reformulate a program into a different notation in order to analyze the program. The system is especially suited for analyzing multi-threaded JAVA applications, where normal testing usually falls short. The system can find deadlocks and violations of boolean assertions stated by the programmer in a special assertion language. This document explains how to Use JPF.

Havelund, Klaus

1999-01-01

163

Statechart Analysis with Symbolic PathFinder  

NASA Technical Reports Server (NTRS)

We report here on our on-going work that addresses the automated analysis and test case generation for software systems modeled using multiple Statechart formalisms. The work is motivated by large programs such as NASA Exploration, that involve multiple systems that interact via safety-critical protocols and are designed with different Statechart variants. To verify these safety-critical systems, we have developed Polyglot, a framework for modeling and analysis of model-based software written using different Statechart formalisms. Polyglot uses a common intermediate representation with customizable Statechart semantics and leverages the analysis and test generation capabilities of the Symbolic PathFinder tool. Polyglot is used as follows: First, the structure of the Statechart model (expressed in Matlab Stateflow or Rational Rhapsody) is translated into a common intermediate representation (IR). The IR is then translated into Java code that represents the structure of the model. The semantics are provided as "pluggable" modules.

Pasareanu, Corina S.

2012-01-01

164

Test-mass module for DECIGO Pathfinder  

NASA Astrophysics Data System (ADS)

DECIGO Pathfinder (DPF) is the first precursory satellite mission for DECIGO (DECi-hertz Interferometer Gravitational wave Observatory), which is a future space gravitational wave antenna. The key instrument of DPF is a Fabry-Perot laser interferometer with freely floating test-masses, demonstrating precision laser interferometry, stabilized laser system and drag-free control system in orbit. A test-mass module is one of the sub-components of the DPF instrument, realizing non-contact suspension of the test mass in space, which provides capabilities of local sensing/actuation, test-mass lock mechanism and charge management system. In this article, the test-mass module system is reviewed.

Sato, Shuichi; Torii, Yasuo; Wakabayashi, Yaka; Ejiri, Yumiko; Suzuki, Rieko; Ueda, Akitoshi; Kawamura, Seiji; Araya, Akito; Ando, Masaki; Obuchi, Yoshiyuki; Okada, Norio

2010-05-01

165

Imager for Mars Pathfinder (IMP) image calibration  

USGS Publications Warehouse

The Imager for Mars Pathfinder returned over 16,000 high-quality images from the surface of Mars. The camera was well-calibrated in the laboratory, with <5% radiometric uncertainty. The photometric properties of two radiometric targets were also measured with 3% uncertainty. Several data sets acquired during the cruise and on Mars confirm that the system operated nominally throughout the course of the mission. Image calibration algorithms were developed for landed operations to correct instrumental sources of noise and to calibrate images relative to observations of the radiometric targets. The uncertainties associated with these algorithms as well as current improvements to image calibration are discussed. Copyright 1999 by the American Geophysical Union.

Reid, R. J.; Smith, P. H.; Lemmon, M.; Tanner, R.; Burkland, M.; Wegryn, E.; Weinberg, J.; Marcialis, R.; Britt, D. T.; Thomas, N.; Kramm, R.; Dummel, A.; Crowe, D.; Bos, B. J.; Bell, III, J. F.; Rueffer, P.; Gliem, F.; Johnson, J. R.; Maki, J. N.; Herkenhoff, K. E.; Singer, R. B.

1999-01-01

166

Statistical Analysis of LISA Pathfinder Noise  

NASA Astrophysics Data System (ADS)

LISA Pathfinder (LPF) is an European Space Agency mission aiming to create the quietest environment for free-falling test masses in order to pave the way to the forthcoming space-based gravitational wave detectors. Reaching such an ambitious target will require a significant amount of system optimisation and characterisation, which will in turn require accurate and quantitative noise analysis procedures. In this paper we present a statistical procedure for the analysis of the noise in spectral domain that is based on the Kolmogorov-Smirnov test. The application on LPF synthetic data reveals the versatility of the Kolmogorov-Smirnov approach, which can easily cope with the correlations introduced by the Welch's overlapped segment averaging method for the calculation of the sample spectrum.

Ferraioli, L.

2013-01-01

167

Mars Pathfinder airbag impact attenuation system  

SciTech Connect

The Mars Pathfinder spacecraft, scheduled for launch in November 1996, is designed to validate a low cost Entry, Descent, and Landing system and to perform scientific surface operations. The Jet Propulsion Laboratory and Sandia National Laboratories teamed to design, fabricate, test and validate a prototype 0.38 scale model of an airbag impact attenuation system. A computer code was developed to predict the performance of the airbag system. A test program in Sandia`s High Altitude Chamber was performed to validate the code and demonstrate the feasibility of the airbag concept and design. In addition, freefall tests were performed at representative velocities to demonstrate the structural integrity of the airbag system design. The feasibility program demonstrated that the airbag impact attenuation design will protect the lander upon impact with the Martian surface.

Waye, D.E.; Cole, J.K. [Sandia National Labs., Albuquerque, NM (United States); Rivellini, T.P. [California Institute of Technology, Pasadena, CA (United States). Jet Propulsion Lab.

1995-04-01

168

Topographic Map of Pathfinder Landing Site  

NASA Technical Reports Server (NTRS)

Topographic map of the landing site, to a distance of 60 meters from the lander in the LSC coordinate system. The lander is shown schematically in the center; 2.5 meter radius circle (black) centered on the camera was not mapped. Gentle relief [root mean square (rms) elevation variation 0.5 m; rms a directional slope 4O] and organization of topography into northwest and northeast-trending ridges about 20 meters apart are apparent. Roughly 30% of the illustrated area is hidden from the camera behind these ridges. Contours (0.2 m interval) and color coding of elevations were generated from a digital terrain model, which was interpolated by kriging from approximately 700 measured points. Angular and parallax point coordinates were measured manually on a large (5 m length) anaglyphic uncontrolled mosaic and used to calculate Cartesian (LSC) coordinates. Errors in azimuth on the order of 10 are therefore likely; elevation errors were minimized by referencing elevations to the local horizon. The uncertainty in range measurements increases quadratically with range. Given a measurement error of 1/2 pixel, the expected precision in range is 0.3 meter at 10 meter range, and 10 meters at 60 meter range. Repeated measurements were made, compared, and edited for consistency to improve the range precision. Systematic errors undoubtedly remain and will be corrected in future maps compiled digitally from geometrically controlled images. Cartographic processing by U.S. Geological Survey.

NOTE: original caption as published in Science Magazine

Mars Pathfinder is the second in NASA's Discovery program of low-cost spacecraft with highly focused science goals. The Jet Propulsion Laboratory, Pasadena, CA, developed and manages the Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. JPL is a division of the California Institute of Technology (Caltech).

1997-01-01

169

Exobiology site priorities for Mars Pathfinder  

NASA Technical Reports Server (NTRS)

The fact that life developed on the Earth within the first billion years of its history makes it quite plausible that life may have also developed on Mars. If life did develop on Mars, it undoubtedly left behind a fossil record. Such a fossil record is likely to be more accessible than either subsurface environments that may harbor life, or scattered 'oases' that may be present at the surface. Consequently, the post-Viking approach of Mars exobiology has shifted focus to search for evidence of an ancient martian biosphere. This has led to the emergence of a new subdiscipline of paleontology, herein termed 'exopaleontology', which deals with the exploration for fossils on other planets and whose core concepts derive from Earth-based Precambrian paleontology, microbial ecology, and sedimentology. Potential targets on Mars for subaqueous spring deposits, sedimentary cements, and evaporites are ancient terminal lake basins where hydrological systems could have endured for some time under arid conditions. Potential targets for the Mars Pathfinder mission include channeled impact craters and areas of deranged drainage associated with outflows in northwest Arabia and Xanthe Terra, where water may have ponded temporarily to form lakes. The major uncertainty of such targets is their comparatively younger age and the potentially short duration of hydrological activity compared to older paleolake basins found in the southern hemisphere. However, it has been suggested that cycles of catastrophic flooding associated with Tharsis volcanism may have sustained a large body of water, Oceanus Borealis, in the northern plains area until quite late in martian history. Although problematic, the shoreline areas of the proposed northern ocean provide potential targets for a Mars Pathfinder mission aimed at exploring for carbonates or other potentially fossiliferous marine deposits. Carbonates and evaporites possess characteristic spectra signatures in the near-infrared and should be detectable using rover-based spectroscopy and other methods for in situ mineralogical analysis.

Farmer, Jack D.; Desmarais, David J.

1994-01-01

170

Rivers, runoff, and reefs  

NASA Astrophysics Data System (ADS)

The role of terrigenous sediment in controlling the occurrence of coral reef ecosystems is qualitatively understood and has been studied at local scales, but has not been systematically evaluated on a global-to-regional scale. Current concerns about degradation of reef environments and alteration of the hydrologic and sediment cycles place the issue at a focal point of multiple environmental concerns. We use a geospatial clustering of a coastal zone database of river and local runoff identified with 0.5° grid cells to identify areas of high potential runoff effects, and combine this with a database of reported coral reef locations. Coastal cells with high runoff values are much less likely to contain reefs than low runoff cells and GIS buffer analysis demonstrates that this inhibition extends to offshore ocean cells as well. This analysis does not uniquely define the effects of sediment, since salinity, nutrients, and contaminants are potentially confounding variables also associated with runoff. However, sediment effects are likely to be a major factor and a basis is provided for extending the study to higher resolution with more specific variables.

McLaughlin, C. J.; Smith, C. A.; Buddemeier, R. W.; Bartley, J. D.; Maxwell, B. A.

2003-10-01

171

Reefs since Columbus  

Microsoft Academic Search

History shows that Caribbean coastal ecosystems were severely degraded long before ecologists began to study them. Large vertebrates such as the green turtle, hawksbill turtle, manatee and extinct Caribbean monk seal were decimated by about 1800 in the central and northern Caribbean, and by 1990 elsewhere. Subsistence over-fishing subsequently decimated reef fish populations. Local fisheries accounted for a small fraction

J. B. C. Jackson

1997-01-01

172

Coral Reef Biological Criteria  

EPA Science Inventory

Coral reefs worldwide are experiencing decline from a variety of stressors. Some important stressors are land-based sources of pollution and human activities in the coastal zone. However, few tools are available to offset the impact of these stressors. The Clean Water Act (CWA...

173

Create a Coral Reef  

NSDL National Science Digital Library

Educator Amy O'Donnell from the American Museum of Natural History guides learners to create a diorama of a coral reef. Learners will use craft skills to transform household materials into simulated brain coral, sea fans, sea anemones, and a sponge. This resource contains background information about coral and the use of dioramas in museums. Also includes extension ideas.

History, American M.

2012-06-26

174

CORAL REEF BIOCRITERIA  

EPA Science Inventory

Coral reefs worldwide are experiencing the greatest decline of their known existence and few tools are available to offset the growing impacts of human coastal and watershed activities. Biocriteria are a potentially effective means to evaluate and restore impaired waters, but are...

175

The Coral Reef Ecosystem  

NSDL National Science Digital Library

Students examine a coral reef ecosystem to learn about its living and non-living parts and how they interact. They apply what they have learned to explore the world's biomes, including how the animals in each are adapted to their environment.

Foundation, Wgbh E.

2007-04-19

176

PATHFINDER Intelligence Software (Version 8.0) (on Magnetic Tape).  

National Technical Information Service (NTIS)

PATHFINDER provides researchers, business analysts, and planners with computer tools and methods to analyze and gain intelligence from large amounts of textual information. Its software tools allow relationships of people, facilities, or other user-define...

1995-01-01

177

The Mars Pathfinder Outreach Project: A Rural Model  

NASA Astrophysics Data System (ADS)

The Montana Mars Pathfinder Outreach Project (MPOP) has completed a successful year of interactive presentations with K-12 students across the west. Carefully selected Montana State University undergraduates visited over 4000 students in the year preceding the Pathfinder landing on Mars. Each presentation showcased a computer generated video of the Pathfinder launch and mission and a slide set about Mars along with engaging discussion between the students and the presenters. Teachers received a packet containing a mission fact sheet, a Pathfinder poster, pins, stickers and informational handouts. This high impact, low budget ($10,000) project proved very popular with students, teachers, principals and parents. In this talk we will discuss the organizational network, budget and time commitment needed to bring a project such as this to your area. Materials and monetary support for this project were provided by the Jet Propulsion Laboratory(JPL Contract #960543) and the Montana Space Grant Consortium.

Larson, Shane L.; Larson, Michelle B.; Hiscock, William A.

1998-04-01

178

Miocene reefs in western Mediterranean  

SciTech Connect

Coral reefs were particularly abundant and well developed during the late Tortonian and Messinian in southeastern Spain, the Balearic Islands, Italy, Sicily, Algeria, and Morocco. These reefs occurred just before and during the deposition of the thick Messinian evaporite units in the basinal areas and disappeared completely from Mediteranean during the early Pliocene. Most of the coral reefs are fringing terrigenous coastal fan complexes with very small lagoons and show progradation of less than 2 km. Some of the reefs occur on, or are intercalated with, Neogene volcanics or Messinian evaporites. Barrier-reef complexes are less common, have extensive lagoons behind them, and show complex progradational geometries more than 10 km wide. Excellent outcrops allow detailed reconstruction of paleogeography and sea level changes. Progradation predominated during phases of relative sea level drops and stillsands, while significant retrogradation occurred during sea level rises. The coral reef wall framework is commonly less than 20 m thick and is dominated by Porites and, locally, Tarbellastrae. Older Miocene reefs are less well developed, but show greater diversity of corals and reef organisms. Younger Miocene reef complexes occurring in open ocean settings are formed by only one branching coral genus (Porites or, locally, Tarbellastraea) with branching colonies up to 7 m high. Halimeda sands are particularly abundant in the upper reef slopes with occasional intercalations of red algae pavements that most likely coincide with episodes of terrigenous influx.

Esteban, M.

1988-01-01

179

The Barrier Reef sediment apron: Tobacco Reef, Belize  

NASA Astrophysics Data System (ADS)

Sedimentological and biological surveys of the back-reef sediment apron of Tobacco Reef, a continuous segment of the Belizean Barrier Reef, reveal five distinct biogeological zones: (1) coralline-coral- Dictyota pavement, (2) Turbinaria-Sargassum rubble, (3) Laurencia-Acanthophora sand and gravel, (4) bare sand and 95 Thalassia sand. These zones parallel the entire 9-km reef. The distribution of these zones is related to the spatial patterns of fish herbivory, the size of bottom sediments, and the stability of the substrate. Sedimentological and hydrodynamic studies indicate that most of the sediments in this area are transported from the reef crest and fore reef during periods of storm or hurricane activity and that their size distribution is largely the result of differential transport by high bottom-water velocities during those periods.

MacIntyre, Ian G.; Graus, Richard R.; Reinthal, Peter N.; Littler, Mark M.; Littler, Diane S.

1987-07-01

180

Reef Fishes of Saba Bank, Netherlands Antilles: Assemblage Structure across a Gradient of Habitat Types  

PubMed Central

Saba Bank is a 2,200 km2 submerged carbonate platform in the northeastern Caribbean Sea off Saba Island, Netherlands Antilles. The presence of reef-like geomorphic features and significant shelf edge coral development on Saba Bank have led to the conclusion that it is an actively growing, though wholly submerged, coral reef atoll. However, little information exists on the composition of benthic communities or associated reef fish assemblages of Saba Bank. We selected a 40 km2 area of the bank for an exploratory study. Habitat and reef fish assemblages were investigated in five shallow-water benthic habitat types that form a gradient from Saba Bank shelf edge to lagoon. Significant coral cover was restricted to fore reef habitat (average cover 11.5%) and outer reef flat habitat (2.4%) and declined to near zero in habitats of the central lagoon zone. Macroalgae dominated benthic cover in all habitats (average cover: 32.5 – 48.1%) but dominant algal genera differed among habitats. A total of 97 fish species were recorded. The composition of Saba Bank fish assemblages differed among habitat types. Highest fish density and diversity occurred in the outer reef flat, fore reef and inner reef flat habitats. Biomass estimates for commercially valued species in the reef zone (fore reef and reef flat habitats) ranged between 52 and 83 g/m2. The composition of Saba Bank fish assemblages reflects the absence of important nursery habitats, as well as the effects of past fishing. The relatively high abundance of large predatory fish (i.e. groupers and sharks), which is generally considered an indicator of good ecosystem health for tropical reef systems, shows that an intact trophic network is still present on Saba Bank.

Toller, Wes; Debrot, Adolphe O.; Vermeij, Mark J. A.; Hoetjes, Paul C.

2010-01-01

181

NOAA Coral Reef Watch: Decision Support Tools for Coral Reef Managers  

NASA Astrophysics Data System (ADS)

A multitude of natural and anthropogenic stressors exert substantial influence on coral reef ecosystems and contribute to bleaching events, slower coral growth, infectious disease outbreaks, and mortality. Satellite-based observations can monitor, at a global scale, environmental conditions that influence both short-term and long-term coral reef ecosystem health. From research to operations, NOAA Coral Reef Watch (CRW) incorporates paleoclimatic, in situ, and satellite-based biogeophysical data to provide near-real-time and forecast information and tools to help managers, researchers, and other stakeholders interpret coral health and stress. CRW has developed an operational, near-real-time product suite that includes sea surface temperature (SST), SST time series data, SST anomaly charts, coral bleaching HotSpots, and Degree Heating Weeks (DHW). Bi-weekly global SST analyses are based on operational nighttime-only SST at 50-km resolution. CRW is working to develop high-resolution products to better address thermal stress on finer scales and is applying climate models to develop seasonal outlooks of coral bleaching. Automated Satellite Bleaching Alerts (SBAs), available at Virtual Stations worldwide, provide the only global early-warning system to notify managers of changing reef environmental conditions. Currently, CRW is collaborating with numerous domestic and international partners to develop new tools to address ocean acidification, infectious diseases of corals, combining light and temperature to detect coral photosystem stress, and other parameters.

Rauenzahn, J.; Eakin, C.; Skirving, W. J.; Burgess, T.; Christensen, T.; Heron, S. F.; Li, J.; Liu, G.; Morgan, J.; Nim, C.; Parker, B. A.; Strong, A. E.

2010-12-01

182

Ecological intereactions of reef building corals  

EPA Science Inventory

Coral reefs are very important marine ecosystems because they support tremendous biodiversity and reefs are critical economic resources many coastal nations. Tropical reef structures are largely built by stony corals. This presentation provides background on basic coral biology t...

183

Welcome to the Wet Tropics: the importance of weather in reef tourism resilience1  

Microsoft Academic Search

As one of Australia's iconic tourism attractions and one of the seven natural wonders of the world, the Great Barrier Reef (GBR) is an important economic, social and natural resource for Queensland's Tropical North. However, the long-term prognosis for the health of the reef and by implication, the industries dependent on it, is not positive. So far much attention has

Alexandra Coghlan; Bruce Prideaux

2009-01-01

184

Coral Reef Protection: A Watershed Approach  

NSDL National Science Digital Library

EPA's home page on coral reef protection activities, including The International Coral Reef Initiative, and The Coral Reef Symposium. A tremendous resource for educators interested in coral reef basics through advanced topics such as coral reef ecology and legislation. Site includes peer-reviewed journal articles, factsheets, maps, and video. The Links section is packed with extensive coral reef information sites covering international and domestic initiatives, research, and even a section for kids and teachers.

185

International Society for Reef Studies  

NSDL National Science Digital Library

Located within the Florida Institute of Technology, the International Society for Reef Studies (ISRS) was founded in 1980, and is designed to disseminate its findings on both living and fossil coral reefs to fellow scholars around the globe and the general public. Before delving into the main site, visitors will want to look through the ISRS in-house publication "Reef Encounters" to get a sense of the various projects the organization is currently working on, and of course, to read brief summaries of its research findings. Of course, for those who already are passionate about coral reefs, there is also a link to sign up for the NOAA "Coral List" forum. The resources section of the site is another good place to look for outside Web resources on other coral reef societies, marine laboratories, and government sites that contain materials on coral reefs and marine biology.

186

Triassic Reefs of the Tethys  

Microsoft Academic Search

\\u000a The evolution of Triassic reefs started with a long-lasting global crisis of the metazoan reef ecosystem after the Permian—Triassic\\u000a mass extinction (about 12 Ma), followed by a relatively rapid recovery during the Middle Triassic. Reef systems were differentiated\\u000a during the Upper Triassic but were severely affected by a global crisis at the Triassic—Jurasic boundary. The present contribution\\u000a is focused on

Erik Flügel; Baba Senowbari-Daryan

187

Spatial Resilience of Coral Reefs  

Microsoft Academic Search

There have been several earlier studies that addressed the influence of natural disturbance regimes on coral reefs. Humans\\u000a alter natural disturbance regimes, introduce new stressors, and modify background conditions of reefs. We focus on how coral\\u000a reef ecosystems relate to disturbance in an increasingly human-dominated environment. The concept of ecosystem resilience—that\\u000a is, the capacity of complex systems with multiple stable

Magnus Nyström; Carl Folke

2001-01-01

188

Coral Reefs in Hot Water  

NSDL National Science Digital Library

In this activity, student teams identify the locations of coral reefs around the world, examine infrared satellite images of the Earth, and research the impacts that are threatening the survival of coral reefs. Each team creates a short oral presentation describing the coral reef they have researched. Students then plot on a composite map the locations where coral bleaching is occurring. Student worksheets, a teacher guide, and assessment rubric are included. This activity is part of Coastal Areas: Coral Reefs in Hot Water, part of the lesson series, The Potential Consequences of Climate Variability and Change.

189

Rivers, runoff, and reefs  

Microsoft Academic Search

Theroleofterrigenoussedimentincontrollingtheoccurrenceofcoralreefecosystemsisqualitatively understoodandhasbeen studied atlocal scales,but hasnotbeen systematically evaluatedonaglobal-to-regional scale.Current concernsaboutdegradation ofreefenvironments andalteration ofthe hydrologicandsedimentcyclesplacetheissueatafocalpointofmultiple environmental concerns. We use a geospatial clustering of a coastal zone database of river and local runoff identified with 0.5j grid cells to identify areas of high potential runoff effects, and combine this with a database of reported coral reef locations. Coastal cells with high runoff

C. J. McLaughlin; C. A. Smith; R. W. Buddemeier; J. D. Bartley; B. A. Maxwell

190

Data Analysis for the LISA Pathfinder Mission  

NASA Technical Reports Server (NTRS)

The LTP (LISA Technology Package) is the core part of the Laser Interferometer Space Antenna (LISA) Pathfinder mission. The main goal of the mission is to study the sources of any disturbances that perturb the motion of the freely-falling test masses from their geodesic trajectories as well as 10 test various technologies needed for LISA. The LTP experiment is designed as a sequence of experimental runs in which the performance of the instrument is studied and characterized under different operating conditions. In order to best optimize subsequent experimental runs, each run must be promptly analysed to ensure that the following ones make best use of the available knowledge of the instrument ' In order to do this, all analyses must be designed and tested in advance of the mission and have sufficient built-in flexibility to account for unexpected results or behaviour. To support this activity, a robust and flexible data analysis software package is also required. This poster presents two of the main components that make up the data analysis effort: the data analysis software and the mock-data challenges used to validate analysis procedures and experiment designs.

Thorpe, James Ira

2009-01-01

191

Bayesian model selection for LISA pathfinder  

NASA Astrophysics Data System (ADS)

The main goal of the LISA Pathfinder (LPF) mission is to fully characterize the acceleration noise models and to test key technologies for future space-based gravitational-wave observatories similar to the eLISA concept. The data analysis team has developed complex three-dimensional models of the LISA Technology Package (LTP) experiment onboard the LPF. These models are used for simulations, but, more importantly, they will be used for parameter estimation purposes during flight operations. One of the tasks of the data analysis team is to identify the physical effects that contribute significantly to the properties of the instrument noise. A way of approaching this problem is to recover the essential parameters of a LTP model fitting the data. Thus, we want to define the simplest model that efficiently explains the observations. To do so, adopting a Bayesian framework, one has to estimate the so-called Bayes factor between two competing models. In our analysis, we use three main different methods to estimate it: the reversible jump Markov chain Monte Carlo method, the Schwarz criterion, and the Laplace approximation. They are applied to simulated LPF experiments in which the most probable LTP model that explains the observations is recovered. The same type of analysis presented in this paper is expected to be followed during flight operations. Moreover, the correlation of the output of the aforementioned methods with the design of the experiment is explored.

Karnesis, Nikolaos; Nofrarias, Miquel; Sopuerta, Carlos F.; Gibert, Ferran; Armano, Michele; Audley, Heather; Congedo, Giuseppe; Diepholz, Ingo; Ferraioli, Luigi; Hewitson, Martin; Hueller, Mauro; Korsakova, Natalia; McNamara, Paul W.; Plagnol, Eric; Vitale, Stefano

2014-03-01

192

The Mars Pathfinder Mission and Science Results  

NASA Astrophysics Data System (ADS)

Mars Pathfinder, the first low-cost, quick Discovery class mission to be completed, successfully landed on the surface of Mars on July 4, 1997, deployed and navigated a small rover, and collected data from 3 science instruments and 10 technology experiments. The mission operated on Mars for 3 months and returned 2.3 Gbits of new data, including over 16,500 lander and 550 rover images, 16 chemical analyses of rocks and soil, and 8.5 million individual temperature, pressure and wind measurements. The rover traversed 100 m clockwise around the lander, exploring about 200 square meters of the surface. The mission captured the imagination of the public, and garnered front page headlines during the first week. A total of about 566 million internet "hits" were registered during the first month of the mission, with 47 million "hits" on July 8th alone, making the Pathfinder landing by far the largest internet event in history at the time. Pathfinder was the first mission to deploy a rover on Mars. It carried a chemical analysis instrument, to characterize the rocks and soils in a landing area over hundreds of square meters on Mars, which provided a calibration point or "ground truth" for orbital remote sensing observations. The combination of spectral imaging of the landing area by the lander camera, chemical analyses aboard the rover, and close-up imaging of colors, textures and fabrics with the rover cameras offered the potential of identifying rocks (petrology and mineralogy). With this payload, a landing site in Ares Vallis was selected because it appeared acceptably safe and offered the prospect of analyzing a variety of rock types expected to be deposited by catastrophic floods, which enabled addressing first-order scientific questions such as differentiation of the crust, the development of weathering products, and the nature of the early Martian environment and its subsequent evolution. The 3 instruments and rover allowed seven areas of scientific investigation: the geology and geomorphology of the surface, mineralogy and geochemistry of rocks and soils, physical properties of surface materials, magnetic properties of airborne dust, atmospheric science including aerosols, and rotational and orbital dynamics of Mars. Scientists were assembled into 7 Science Operations Groups that were responsible for requesting measurements by the 3 instruments, rover and engineering subsystems for carrying out their scientific investigations and for analyzing the data and reporting on their findings. The spacecraft was launched on December 4, 1996 and had a 7 month cruise to Mars, with four trajectory correction maneuvers. The vehicle entered the atmosphere directly following cruise stage separation. Parachute deployment, heatshield and lander separation, radar ground acquisition, airbag inflation and rocket ignition all occurred before landing at 2:58 AM true local solar time (9:56:55 AM PDT). The lander bounced at least 15 times up to 12 in high without airbag rupture, demonstrating the robustness of this landing system. Reconstruction of the final landing sequence indicates that the parachute/backshel1/1ander was tilted due to a northwest directed wind and wind shear, which resulted in the lander bouncing about I km to the northwest and initially downhill about 20 m from where the solid rockets fired. Two anomalously bright spots located in the lander scene are likely the heatshield, which continued in a ballistic trajectory about 2 km downrange (west southwest), and the backshell/parachute, which stayed nearer to where the rockets fired. Unconnected disturbed soil patches in the scene indicate that the final few bounces of the lander were from the east-southeast and were followed by a gentle roll to the west before coming to rest on the base petal. The location of the lander away from where the solid rockets fired and considerations of the exhaust products used to inflate the airbags and their fate, indicate that the Pathfinder landing system is one of the cleanest designed leaving the local area essentia

Golombek, M. P.

1999-01-01

193

Data Analysis for the LISA Pathfinder Mission  

NASA Astrophysics Data System (ADS)

As the launch time of LISA Pathfinder draws near, there is increasing effort being employed on the preparation and development of the on-board experiments and their associated data analysis procedures. Due to the relatively short duration of the mission, and because of the large number of investigations we wish to perform, the on-line analysis and assessment of each investigation is essential for the successful planning of the mission time-line. In the past, the data analysis effort has focussed on developing a software environment (LTPDA) that is both robust and flexible. The software also needs to meet other requirements arising from operational and scientific constraints. LTPDA is in a mature state now and a brief report will be given in this talk. The team is now focussed on the development of the experiments to be performed on orbit. This involves developing the tele-command sequences needed to perform the experiments, the development of the data analysis procedures and algorithms required to analyse each experiment, and the validation of the full chain using LPF simulators. This talk will review the entire data analysis effort and present an overview of the planned experiments in the context of data analysis.

Hewitson, Martin

2012-07-01

194

Confronting the coral reef crisis  

Microsoft Academic Search

The worldwide decline of coral reefs calls for an urgent reassessment of current management practices. Confronting large-scale crises requires a major scaling-up of management efforts based on an improved understanding of the ecological processes that underlie reef resilience. Managing for improved resilience, incorporating the role of human activity in shaping ecosystems, provides a basis for coping with uncertainty, future changes

T. P. Hughes; C. Folke; M. Nyström; D. R. Bellwood

2004-01-01

195

Development of Artificial Oyster Reefs.  

National Technical Information Service (NTIS)

One hundred fourteen acres of public oyster reefs were constructed at an average cost of $1,867/acre in Bay, Brevard, Franklin, Wakulla, and Walton Counties, Florida. These reefs were constructed using 402,244 bushels of shucked Callico scallop shell, and...

W. K. Whitfield

1978-01-01

196

FORTIS: pathfinder to the Lyman continuum  

NASA Astrophysics Data System (ADS)

Shull et al. have asserted that the contribution of stars, relative to quasars, to the metagalactic background radiation that ionizes most of the baryons in the universe remains almost completely unknown at all epochs. The potential to directly quantify this contribution at low redshift has recently become possible with the identification by GALEX of large numbers of sparsely distributed faint ultraviolet galaxies. Neither STIS nor FUSE nor GALEX have the ability to efficiently survey these sparse fields and directly measure the Lyman continuum radiation that may leak into the low redshift (z < 0.4) intergalactic medium. We present here a design for a new type of far ultraviolet spectrograph, one that is more sensitive, covers wider fields, and can provide spectra and images of a large number of objects simultaneously, called the Far-ultraviolet Off Rowland-circle Telescope for Imaging and Spectroscopy (FORTIS). We intend to use a sounding rocket flight to validate the new instrument with a simple long-slit observation of the starburst populations in the galaxy M83. If however, the long-slit were replaced with microshutter array, this design could isolate the chains of blue galaxies found by GALEX over an ~30' diameter field-of-view and directly address the Lyman continuum problem in a long duration orbital mission. Thus, our development of the sounding rocket instrument is a pathfinder to a new wide field spectroscopic technology for enabling the potential discovery of the long hypothesized but elusive Lyman continuum radiation that is thought to leak from low redshift galaxies and contribute to the ionization of the universe.

McCandliss, Stephan R.; France, Kevin; Feldman, Paul D.; Glazebrook, Karl; Meurer, Gerhardt; Bianchi, Luciana; Moos, H. W.; Kruk, Jeffrey W.; Blair, William P.; Baldry, Ivan

2004-10-01

197

PBS Online NewsHour: Coral Reefs  

NSDL National Science Digital Library

In-depth coverage of the role of coral reefs in environment, medicinal properties, and conservation efforts, together with instructional materials. Includes lesson plan; interactive on coral-reef building blocks; extended interviews; and stories on reef threats, international treaties, Caribbean reefs, mangrove shields, and the Aquarius undersea lab. Main story is provided as text, streaming video, and RealAudio.

198

Mars Pathfinder Rover-Lewis Research Center Technology Experiments Program  

NASA Technical Reports Server (NTRS)

An overview of NASA's Mars Pathfinder Program is given and the development and role of three technology experiments from NASA's Lewis Research Center and carried on the Mars Pathfinder rover is described. Two recent missions to Mars were developed and managed by the Jet Propulsion Laboratory, and launched late last year: Mars Global Surveyor in November 1996 and Mars Pathfinder in December 1996. Mars Global Surveyor is an orbiter which will survey the planet with a number of different instruments, and will arrive in September 1997, and Mars Pathfinder which consists of a lander and a small rover, landing on Mars July 4, 1997. These are the first two missions of the Mars Exploration Program consisting of a ten year series of small robotic martian probes to be launched every 26 months. The Pathfinder rover will perform a number of technology and operational experiments which will provide the engineering information necessary to design and operate more complex, scientifically oriented surface missions involving roving vehicles and other machinery operating in the martian environment. Because of its expertise in space power systems and technologies, space mechanisms and tribology, Lewis Research Center was asked by the Jet Propulsion Laboratory, which is heading the Mars Pathfinder Program, to contribute three experiments concerning the effects of the martian environment on surface solar power systems and the abrasive qualities of the Mars surface material. In addition, rover static charging was investigated and a static discharge system of several fine Tungsten points was developed and fixed to the rover. These experiments and current findings are described herein.

Stevenson, Steven M.

1997-01-01

199

Mars Pathfinder Microrover- Implementing a Low Cost Planetary Mission Experiment  

NASA Technical Reports Server (NTRS)

The Mars Pathfinder Microrover Flight Experiment (MFEX) is a NASA Office of Space Access and Technology (OSAT) flight experiment which has been delivered and integrated with the Mars Pathfinder (MPF) lander and spacecraft system. The total cost of the MFEX mission, including all subsystem design and development, test, integration with the MPF lander and operations on Mars has been capped at $25 M??is paper discusses the process and the implementation scheme which has resulted in the development of this first Mars rover.

Matijevic, J.

1996-01-01

200

Atmosphere structure and meteorology instrument for Mars Pathfinder  

NASA Technical Reports Server (NTRS)

The MESUR Science Definition Team recommended that all MESUR probes, including Pathfinder, carry an ASI/MET experiment, in order that no opportunity be lost to characterize the atmosphere of Mars in passing through it. The experiment was thus included on Pathfinder from the start (February 1992), but on an essentially noninterference basis: It was to make no unusual demands on the spacecraft. A Science Advisory Team was appointed by NASA Headquarters in September 1993 first met on November 3rd to initiate formal science participation, and the level of activity has since been high. The instrument passed its Preliminary Design Review on February 28th.

Seiff, Alvin

1994-01-01

201

The International Coral Reef Information Network  

NSDL National Science Digital Library

This extensive site was originally created to support coral reef conservation by the International Coral Reef Initiative (ICRI). The site serves to provide general coral reef information, tools and resources, and a central coral reef communications and network hub. The site also provides a library which houses descriptions of brochures, books, videos and other items suitable for coral reef awareness and education efforts. Some publications are available for download directly from this site, while others are available for purchase.

International Coral Reef Action Network (ICRAN)

202

Adaptive Avoidance of Reef Noise  

PubMed Central

Auditory information is widely used throughout the animal kingdom in both terrestrial and aquatic environments. Some marine species are dependent on reefs for adult survival and reproduction, and are known to use reef noise to guide orientation towards suitable habitat. Many others that forage in food-rich inshore waters would, however, benefit from avoiding the high density of predators resident on reefs, but nothing is known about whether acoustic cues are used in this context. By analysing a sample of nearly 700,000 crustaceans, caught during experimental playbacks in light traps in the Great Barrier Reef lagoon, we demonstrate an auditory capability in a broad suite of previously neglected taxa, and provide the first evidence in any marine organisms that reef noise can act as a deterrent. In contrast to the larvae of species that require reef habitat for future success, which showed an attraction to broadcasted reef noise, taxa with a pelagic or nocturnally emergent lifestyle actively avoided it. Our results suggest that a far greater range of invertebrate taxa than previously thought can respond to acoustic cues, emphasising yet further the potential negative impact of globally increasing levels of underwater anthropogenic noise.

Simpson, Stephen D.; Radford, Andrew N.; Tickle, Edward J.; Meekan, Mark G.; Jeffs, Andrew G.

2011-01-01

203

LISA Pathfinder and eLISA news  

NASA Technical Reports Server (NTRS)

Two important gatherings of the space-based gravitational-wave detector community were held in Zurich, Switzerland this past March. The first was a meeting of the Science Working Team for LISA Pathfinder (LPF), a dedicated technology demonstrator mission for a future LISA-like gravitational wave observatory. LPF is entering an extremely exciting phase with launch less than 15 months away. All flight components for both the European science payload, known as the LISA Technology Package (LTP), and the NASA science payload, known as the Space Technology 7 Disturbance Reduction System (ST7-DRS), have been delivered and are undergoing integration. The final flight component for the spacecraft bus, a cold-gas thruster based on the successful GAIA design, will be delivered later this year. Current focus is on completing integration of the science payload (see Figures 1 and 2) and preparation for operations and data analysis. After a launch in Summer 2015, LPF will take approximately 90 days to reach its operational orbit around the Earth-Sun Lagrange point (L1), where it will begin science operations. After 90 days of LTP operations followed by 90 days of DRS operations, LPF will have completed its prime mission of paving the way for a space-based observatory of gravitational waves in the milliHertz band. Immediately following the meeting of the LPF team, the eLISA consortium held its third progress meeting. The consortium (www.elisascience.org) is the organizing body of the European space-based gravitational-wave community, and it was responsible for the "The Gravitational Universe" whitepaper that resulted in the November 2013 election of a gravitational-wave science theme for ESA's Cosmic Visions L3 opportunity. In preparation for an L3 mission concept call, which is expected later this decade, and for launch in the mid 2030s, the eLISA consortium members are coordinating technology development and mission study activities which will build on the LPF results. The final mission concept is expected to include some international (non-European) contributions, and NASA has expressed an interest in participating in this ground-breaking mission. The US research community supports such a collaboration, or any other mission scenario that achieves the high-priority science of a space-based gravitational-wave observatory at the earliest possible date.

Thorpe, James Ira; Mueller, Guido

2014-01-01

204

Upper Permian Capitan Reef  

SciTech Connect

A depositional and diagentic model for the Capitan reef complex (Late Permian, Guadalupian age) has evolved during more than 50 years of outcrop studies in the Guadalupe Mountains of west Texas and New Mexico. The model relates the shelf margin (Capitain Limestone) with equivalent shelf (in ascending order, Seven Rivers, Yates, and Tansill Formations) and basin (Bell Canyon Formation) strata. It has proved to be important in relating hydrocarbon distribution in shelf and basin strata in the Permian basin and has been important as an analog in numerous other basins. Detailed study of the northern rim of the Delaware basin, centering on a 4,800-ft core, has caused us to reevaluate the outcrop-defined depositional model for the Capitan shelf margin along the following themes. Geologic evolution. Progradation of the margin was not uniform throughout deposition of the Capitan as is portrayed in most reconstructions. Outcrop mapping and log correlations, in fact, show that 75% of the total basinward progradation of the Capitan occurred during deposition of the Seven Rivers Formation. This maximum progradation corresponds to back-reef carbonates largely devoid of siliciclastics, thick carbonate debris beds on the slope and basin edge, and thick siliclastics deposited in the basin. Depositional facies and diagenesis. The pisolithic shoal complex, the predominant feature marking the highest part of the shelf margin, was more laterally extensive than known from outcrop.

Harris, P.M.; Garber, R.A.; Grover, G.A.

1988-01-01

205

Miocene reef corals: A review  

SciTech Connect

Tectonic blockage in the Middle East of westward-flowing Tethys surface circulation during the latest Oligocene led to creation in the earliest Miocene of endemic Mediterranean, Western Atlantic-Caribbean, and Indo-Pacific realms. A great reduction in reef coral diversity from 60-80 Oligocene species to 25-35 early Miocene species occurred in the Western Atlantic-Caribbean and Mediterranean areas accompanied by a decrease in reef growth. A slower and less drastic change apparently occurred in the Indo-Pacific area. Early Miocene reef corals of the Western Atlantic-Caribbean comprise a transition between the cosmopolitan Oligocene fauna and its endemic mid-Miocene to modern counterpart. Although early Miocene reefs were dominated by a Porites-Montastrea assemblage, eastward flow of Pacific circulation brought with it ''exotic'' corals such as Coscinaraea and Pseudocolumnastrea. Also, many cosmopolitan genera persisted from the Oligocene. During the middle to late Miocene, most of the species still living on Holocene reefs evolved. As the Mediterranean basin became more restricted, there was a slow decline in reef corals from 20 - 25 species in the Aquitainian to less than five species in the Messinian. Eustatic lowstand led to the extinction of reef-building corals in the late Messinian. In the Indo-Pacific, Neogene evolution of reef corals was conservative. Excluding the Acroporidae and Seriatoporidae, most Holocene framework species had evolved by the middle Miocene. Interplay between regional tectonics and eustatic sea level changes led to extensive development of middle to late Miocene pinnacle reefs over the southwestern Pacific.

Frost, S.H.

1988-01-01

206

Age of tilted reefs, Hawaii.  

USGS Publications Warehouse

Submerged carbonate reefs are preserved as a series of submarine terraces between Molokai and Hawaii along a 200-km span of the SE Hawaiian Ridge. Limestones from 2 of the terraces have been dated at 13 and 120 ka. Recognition that the terraces are tilted permits assignment of about a dozen terraces from 150 to 1300 m depth to 8 general reef platforms. These reefs were drowned by the combined effects of island subsidence and sea level rise at the end of successive glacial stages from 13 to 647 ka. The platforms are tilted 5 m/km SE toward the locus of volcanic centered on the island of Hawaii.-from Authors

Moore, J. G.; Campbell, J. F.

1987-01-01

207

Measuring coral reef community metabolism using new benthic chamber technology  

USGS Publications Warehouse

Accurate measurement of coral reef community metabolism is a necessity for process monitoring and in situ experimentation on coral reef health. Traditional methodologies used for these measurements are effective but limited by location and scale constraints. We present field trial results for a new benthic chamber system called the Submersible Habitat for Analyzing Reef Quality (SHARQ). This large, portable incubation system enables in situ measurement and experimentation on community- scale metabolism. Rates of photosynthesis, respiration, and calcification were measured using the SHARQ for a variety of coral reef substrate types on the reef flat of South Molokai, Hawaii, and in Biscayne National Park, Florida. Values for daily gross production, 24-h respiration, and net calcification ranged from 0.26 to 6.45 g O2 m-2 day-1, 1.96 to 8.10 g O2 m-2 24 h-1, and 0.02 to 2.0 g CaCO3 m -2 day-1, respectively, for all substrate types. Field trials indicate that the SHARQ incubation chamber is an effective tool for in situ isolation of a water mass over a variety of benthic substrate types for process monitoring, experimentation, and other applications.

Yates, K. K.; Halley, R. B.

2003-01-01

208

Coral reef aorta, emergency surgical: case report and literature review.  

PubMed

Coral reef aorta is described as an uncommon entity characterized by the presence of coarse calcifications, which are developed in the visceral aorta. These calcifications grow toward the lumen of the artery and can result in significant stenosis, so that causing malperfusion of the lower limbs, visceral ischemia or hypertension secondary to renal involvement. We report here a case of a 54-year-old patient with coral reef aorta and symptomatic. The clinical presentation of the patient required the surgical approach. A review of literature in major databases was conducted to compare health-related aspects of the disease presentation and management. Coral reef aorta should be considered as the diagnosis for patients with visceral and limbs ischemia. The approach in our case was consistent with other studies previously published in the literature. PMID:25003933

Belczak, Sergio Quilici; Sincos, Igor Rafael; Aun, Ricardo; Costa, Kaline Viana; Araujo, Etianne Andrade

2014-04-01

209

Modis, SeaWIFS, and Pathfinder funded activities  

NASA Technical Reports Server (NTRS)

MODIS (Moderate Resolution Imaging Spectrometer), SeaWIFS (Sea-viewing Wide Field Sensor), Pathfinder, and DSP (Digital Signal Processor) objectives are summarized. An overview of current progress is given for the automatic processing database, client/server status, matchup database, and DSP support.

Evans, Robert H.

1995-01-01

210

Mars Pathfinder and the Exploration of Southern Amazonis Planitia.  

National Technical Information Service (NTIS)

The southern region of Amazonis Planitia provides a variety of target terrains for a roving vehicle such as the Mars Pathfinder Mission. A landing site is proposed at 4 deg N latitude 162 deg W longitude. This area has a reference altitude of between 0 an...

N. G. Barlow

1994-01-01

211

Mars Pathfinder and the exploration of southern Amazonis Planitia  

Microsoft Academic Search

The southern region of Amazonis Planitia provides a variety of target terrains for a roving vehicle such as the Mars Pathfinder Mission. A landing site is proposed at 4 deg N latitude 162 deg W longitude. This area has a reference altitude of between 0 and -1 km and consists of relatively smooth Amazonian-aged deposits within the entire 100 x

Nadine G. Barlow

1994-01-01

212

The AVHRR Pathfinder Sea Surface Temperature Climate Data Record  

Microsoft Academic Search

The Version 5 AVHRR Pathfinder sea surface temperature (SST) climate data record now spans 1985 through 2006 and in the last two years has been used by more than 20,000 people around the world in government agencies, academic institutions, and commercial enterprises. The accuracy, consistency, global scope, and fine spatial and temporal resolution of this reprocessed AVHRR data set make

K. S. Casey; R. W. Reynolds; R. Evans

2006-01-01

213

A Pathfinder for Animal Research and Animal Rights.  

ERIC Educational Resources Information Center

This pathfinder was originally prepared for "Biomedical Research and Animal Rights," a session sponsored by the Veterinary Medical Libraries and Research Libraries Sections of the Medical Library Association. Current resources are described, from bibliographies to electronic bulletin boards, which relate to the issue of laboratory animal welfare…

Anderson, David C.

1992-01-01

214

Ganglion cell axon pathfinding in the retina and optic nerve  

Microsoft Academic Search

The eye is a highly specialized structure that gathers and converts light information into neuronal signals. These signals are relayed along axons of retinal ganglion cells (RGCs) to visual centers in the brain for processing. In this review, we discuss the pathfinding tasks RGC axons face during development and the molecular mechanisms known to be involved. The data at hand

S. F. Oster; M. Deiner; E. Birgbauer; D. W. Sretavan

2004-01-01

215

Sedimentary geomorphology of the Mars Pathfinder Landing Site  

NASA Technical Reports Server (NTRS)

The first landing on Mars in over 20 years will take place July 4, 1997, near te mouth of the Ares Vallis outflow channel located in southeastern Chryse Planitia. Mars Pathfinder, unlike Viking 1, is expected to land on a surface that has a distinct and unambiguous fluvial signature.

Rice, James W., Jr.; Parker, Timothy Jay

1997-01-01

216

Drill/Borescope System for the Mars Polar Pathfinder.  

National Technical Information Service (NTIS)

The primary goals of the Mars Polar Pathfinder (MPP) Discovery Mission are to characterize the composition and structure of Mars' north polar ice cap, and to determine whether a climate record may be preserved in layers of ice and dust. The MPP would land...

D. A. Paige, S. E. Wood, A. R. Vasavada

1993-01-01

217

Atmosphere Structure and Meteorology Instrument for Mars Pathfinder.  

National Technical Information Service (NTIS)

The MESUR Science Definition Team recommended that all MESUR probes, including Pathfinder, carry an ASI/MET experiment, in order that no opportunity be lost to characterize the atmosphere of Mars in passing through it. The experiment was thus included on ...

A. Seiff

1994-01-01

218

Mars Suface Layer Climatology from Viking and Pathfinder  

Microsoft Academic Search

The study of mean flow and turbulence of the atmospheric surface boundary layer on Mars have been based on in-situ wind and temperature data from the Viking and Pathfinder missions. Largely the behaviour of surface layer turbulence and mean flow on Mars is found to obey the same scaling laws as on Earth. The largest micrometeorological differences between the two

S. E. Larsen; H. E. Jørgensen; J. Murphy; J. E. Tillman; J. T. Schoffield

2003-01-01

219

PATHFINDER ATOMIC POWER PLANT COOLANT DISTRIBUTION TESTS. Final Report  

Microsoft Academic Search

Tests were made to determine the head loss coefficient through the inlet ; plenum of the Pathfinder reactor and to determine the now distribution among the ; fuel element nozzles for various operating conditions--with all three pumps ; operating at the same flow rate and with any combination of only two pumps ; operating at the same flow rate. A

J. Wilson; R. Styles

1959-01-01

220

Re-examination of Mars Pathfinder parachute drag coefficient estimate  

NASA Technical Reports Server (NTRS)

The Mars Exploration Rover (MER) mission utilizes the Mars Pathfinder (MPF) parachute design. The MPF parachute drag coefficient is a driver for the MER entry, descent, and landing (EDL) design. As a result, a good estimate of the performance of the MPF parachute at Mars is required.

Desai, P.; Schofield, T.; Lisano, M.

2003-01-01

221

Home Reef, South Pacific  

NASA Technical Reports Server (NTRS)

In the South Pacific, south of Late Island along the Tofua volcanic arc in Tonga, a new volcanic island Home Reef is being re-born. The island is thought to have emerged after a volcanic eruption in mid-August that has also spewed large amounts of floating pumice into Tongan waters and sweeping across to Fiji about 350 km (220 miles) to the west of where the new island has formed. In 2004 a similar eruption created an ephemeral island about 0.5 by 1.5 km (0.3 by 0.9 miles) in size; it was no longer visible in an ASTER image acquired November 2005. This simulated natural color image shows the vegetation-covered stratovolcanic island of Late in the upper right. Home Reef is found in the lower left. The two bluish plumes are hot seawater that is laden with volcanic ash and chemicals; the larger one can be traced for more than 14 km (8.4 miles) to the east. The image was acquired October 10, 2006 and covers an area of 24.3 by 30.2 km. It is located at 18.9 degrees South latitude, 174.7 degrees west longitude.

With its 14 spectral bands from the visible to the thermal infrared wavelength region, and its high spatial resolution of 15 to 90 meters (about 50 to 300 feet), ASTER images Earth to map and monitor the changing surface of our planet.

ASTER is one of five Earth-observing instruments launched December 18, 1999, on NASA's Terra satellite. The instrument was built by Japan's Ministry of Economy, Trade and Industry. A joint U.S./Japan science team is responsible for validation and calibration of the instrument and the data products.

The broad spectral coverage and high spectral resolution of ASTER provides scientists in numerous disciplines with critical information for surface mapping, and monitoring of dynamic conditions and temporal change. Example applications are: monitoring glacial advances and retreats; monitoring potentially active volcanoes; identifying crop stress; determining cloud morphology and physical properties; wetlands evaluation; thermal pollution monitoring; coral reef degradation; surface temperature mapping of soils and geology; and measuring surface heat balance.

The U.S. science team is located at NASA's Jet Propulsion Laboratory, Pasadena, Calif. The Terra mission is part of NASA's Science Mission Directorate.

Size: 24.3 by 30.2 kilometers (15 by 18.6 miles) Location: 18.9 degrees South latitude, 174.7 degrees West longitude Orientation: North at top Image Data: ASTER bands 3, 2, and 1 Original Data Resolution: 15 meters (49.2 feet) Dates Acquired: October 4, 2006

2006-01-01

222

Coral Reef Protection Implementation Plan.  

National Technical Information Service (NTIS)

This document identify policies and actions to implement the Department of Defense's responsibilities under Executive Order 13089 on Coral Reef Protection, and are a requirement of the interim Task Force policy titled 'Oversight of Agency Actions Affectin...

L. K. Lobel P. Lobel

2000-01-01

223

Commencement on a Coral Reef  

ERIC Educational Resources Information Center

Describes an environmental program in which sixteen students and three biology teachers from Northfield Mount Hermon School in Massachusetts spent two weeks examining the ecology of a Caribbean reef.. (JR)

Webster, Steven K.

1973-01-01

224

Role of Shipyard Pollutants in Structuring Coral Reef Microbial Communities: Monitoring Environmental Change and the Potential Causes of Coral Disease.  

National Technical Information Service (NTIS)

The US Navy operates military bases in tropical and sub-tropical seas that are surrounded by coral reefs. Therefore, the goal of this work has been to develop methods for long-term monitoring of the effects of naval activity on the health of these reef ec...

B. W. Fouke

2006-01-01

225

Florida Keys NMS: Coral Reefs  

NSDL National Science Digital Library

Florida Keys National Marine Sanctuary's page with information on coral reefs and links to information on research, restoration and monitoring. Wealth of information on the protection of Florida's coral reefs and the Florida Keys as a whole. Includes an in-class activity for grades K-5, as well as information on a Keys field experience and teacher workshops. Information on safe diving and snorkeling. Education materials available for purchase, including the Seagrass Toolbox.

226

The Revised Coral Reef Hypothesis  

Microsoft Academic Search

The original coral reef hypothesis stated that carbonate production by benthic biota on the world's shallow shelves substantially contributed to the buildup of atmospheric pCO2 during the last deglaciation. We have synthetized the literature on the world's reefs and new data on the distribution of the carbonate platforms (isolated banks and contintent-attached platforms). Strong production and resulting CO2 release started

A. Vecsei; W. H. Berger

2002-01-01

227

Lab 3: Building a Reef  

NSDL National Science Digital Library

During this lab, students learn about the life cycle of corals, including how they grow and reproduce. Students consider the chemistry of seawater and the importance of the symbiotic relationship between corals and zooxanthellae in the formation of coral reefs. They blow CO2 through calcium hydroxide (limewater) to model how respiration assists coral in precipitating calcium carbonate. Students also build on the coral polyp models they made in Lab 2 to demonstrate coral growth, reproduction, and reef formation.

228

Effectiveness of benthic foraminiferal and coral assemblages as water quality indicators on inshore reefs of the Great Barrier Reef, Australia  

NASA Astrophysics Data System (ADS)

Although the debate about coral reef decline focuses on global disturbances (e.g., increasing temperatures and acidification), local stressors (nutrient runoff and overfishing) continue to affect reef health and resilience. The effectiveness of foraminiferal and hard-coral assemblages as indicators of changes in water quality was assessed on 27 inshore reefs along the Great Barrier Reef. Environmental variables (i.e., several water quality and sediment parameters) and the composition of both benthic foraminiferal and hard-coral assemblages differed significantly between four regions (Whitsunday, Burdekin, Fitzroy, and the Wet Tropics). Grain size and organic carbon and nitrogen content of sediments, and a composite water column parameter (based on turbidity and concentrations of particulate matter) explained a significant amount of variation in the data (tested by redundancy analyses) in both assemblages. Heterotrophic species of foraminifera were dominant in sediments with high organic content and in localities with low light availability, whereas symbiont-bearing mixotrophic species were dominant elsewhere. A similar suite of parameters explained 89% of the variation in the FORAM index (a Caribbean coral reef health indicator) and 61% in foraminiferal species richness. Coral richness was not related to environmental setting. Coral assemblages varied in response to environmental variables, but were strongly shaped by acute disturbances (e.g., cyclones, Acanthaster planci outbreaks, and bleaching), thus different coral assemblages may be found at sites with the same environmental conditions. Disturbances also affect foraminiferal assemblages, but they appeared to recover more rapidly than corals. Foraminiferal assemblages are effective bioindicators of turbidity/light regimes and organic enrichment of sediments on coral reefs.

Uthicke, S.; Thompson, A.; Schaffelke, B.

2010-03-01

229

The impacts of tourism on coral reef conservation awareness and support in coastal communities in Belize  

NASA Astrophysics Data System (ADS)

Marine recreational tourism is one of a number of threats to the Belize Barrier Reef but, conversely, represents both a motivation and source of resources for its conservation. The growth of tourism in Belize has resulted in the fact that many coastal communities are in varying stages of a socio-economic shift from dependence on fishing to dependence on tourism. In a nation becoming increasingly dependent on the health of its coral reef ecosystems for economic prosperity, a shift from extractive uses to their preservation is both necessary and logical. Through examining local perception data in five coastal communities in Belize, each attracting different levels of coral reef related tourism, this analysis is intended to explore the relationship between tourism development and local coral reef conservation awareness and support. The results of the analysis show a positive correlation between tourism development and coral reef conservation awareness and support in the study communities. The results also show a positive correlation between tourism development and local perceptions of quality of life, a trend that is most likely the source of the observed relationship between tourism and conservation. The study concludes that, because the observed relationship may be dependent on continued benefits from tourism as opposed to a perceived crisis in coral reef health, Belize must pay close attention to tourism impacts in the future. Failure to do this could result in a destructive feedback loop that would contribute to the degradation of the reef and, ultimately, Belize’s diminished competitiveness in the ecotourism market.

Diedrich, A.

2007-12-01

230

Geomorphology of unique reefs on the western Canadian shelf: sponge reefs mapped by multibeam bathymetry  

Microsoft Academic Search

Multibeam imagery of siliceous sponge reefs (Hexactinellida, Hexactinosida) reveals the setting, form, and organization of five reef complexes on the western Canadian continental shelf. The reefs are built by framework skeleton sponges which trap clay-rich sediments resulting in a distinctive pattern of low intensity backscatter from the reefs that colonize more reflective glacial sediments of higher backscatter intensity. Bathymetry and

Kim W. Conway; J. Vaughn Barrie; Manfred Krautter

2005-01-01

231

Benthic microalgae in coral reef sediments of the southern Great Barrier Reef, Australia  

Microsoft Academic Search

The abundance and productivity of benthic microalgae in coral reef sediments are poorly known compared with other, more conspicuous (e.g. coral zooxanthellae, macroalgae) primary producers of coral reef habitats. A survey of the distribution, biomass, and productivity of benthic microalgae on a platform reef flat and in a cross-shelf transect in the southern Great Barrier Reef indicated that benthic microalgae

C. A. Heil; K. Chaston; A. Jones; P. Bird; B. Longstaff; S. Costanzo; W. C. Dennison

2004-01-01

232

Configuration of small patch reefs and population abundance of a resident reef fish in a complex coral reef landscape  

Microsoft Academic Search

Habitat use by the resident coral reef anemonefish, Amphiprion frenatus, was examined in the complex coral reef landscape of Shiraho Reef, Ishigaki Island, Okinawa, Japan, using an enlarged color\\u000a aerial photograph processed using image analysis software as an accurate field map. The anemonefish inhabit assemblages of\\u000a the host sea anemone, Entacmaea quadricolor (clonal type), which inhabit various patch reefs in

Akihisa Hattori; Miyako Kobayashi

2007-01-01

233

Analyzing Pathfinder data using virtual reality and superresolved imaging  

NASA Astrophysics Data System (ADS)

The Mars Pathfinder mission used a unique capability to rapidly generate and interactively display three-dimensional (3-D) photorealistic virtual reality (VR) models of the Martian surface. An interactive terrain visualization system creates and renders digital terrain models produced from stereo images taken by the Imager for Mars Pathfinder (IMP) camera. The stereo pipeline, an automated machine vision algorithm, correlates features between the left and right images to determine their disparity and computes the corresponding positions using the known camera geometry. These positions are connected to form a polygonal mesh upon which IMP images are overlaid as textures. During the Pathfinder mission, VR models were produced and displayed almost as fast as images were received. The VR models were viewed using MarsMap, an interface that allows the model to be viewed from any perspective driven by a standard three-button computer mouse. MarsMap incorporates graphical representations of the lander and rover and the sequence and spatial locations at which rover data were taken. Graphical models of the rover were placed in the model to indicate the rover position at the end of each day of the mission. Images taken by Sojourner cameras are projected into the model as 2-D ``billboards'' to show their proper perspective. Distance and angle measurements can be made on features viewed in the model using a mouse-driven 3-D cursor and a point-and-click interface. MarsMap was used to assist with archiving and planning Sojourner activities and to make detailed measurements of surface features such as wind streaks and rock size and orientation that are difficult to perform using 2-D images. Superresolution image processing is a computational method for improving image resolution by a factor of n1/2 by combining n independent images. This technique was used on Pathfinder to obtain better resolved images of Martian surface features. We show results from superresolving IMP camera images of six targets including near- and far-field objects and discuss how the resolution improvement aids interpretation. Similar flood deposits can be seen on both of the Twin Peaks that cannot be resolved in raw images. Millimeter-sized pits are resolved on the rocks Wedge and Halfdome. Other rocks at the Pathfinder site exhibit fine-scale layering that is otherwise invisible. Use of the method resulted in the probable discovery of an artifact of intelligent life on Mars: a part of the Pathfinder spacecraft.

Stoker, Carol R.; Zbinden, Eric; Blackmon, Theodore T.; Kanefsky, Bob; Hagen, Joel; Neveu, Charles; Rasmussen, Daryl; Schwehr, Kurt; Sims, Michael

1999-04-01

234

A Night in the Coral Reef  

NSDL National Science Digital Library

Coral reefs are often portrayed as brightly lit, bustling underwater marvels full of colorful creatures. This video segment, adapted from NOVA, paints a different picture as it explores the nocturnal behavior of organisms in the reef.

Foundation, Wgbh E.

2007-04-19

235

Mars Pathfinder First Anniversary Special -- Refined Landing Site Location  

NASA Technical Reports Server (NTRS)

It has been one year since NASA's Return to the Red Planet began with the spectacular landing of Mars Pathfinder and its microrover, Sojourner. The spacecraft bounced onto a flood-washed landscape on July 4, 1997.

Mars Pathfinder was soon joined by the orbiting Mars Global Surveyor on September 11, 1997 (PDT). Mars Global Surveyor's high resolution camera, MOC, took a picture of the Mars Pathfinder landing site region during its 256th orbit on April 22, 1998. This picture--at about 5 meters (11 feet) per pixel--is the best available for the site. The previous best images were from the Viking 1 Orbiter in 1976, and had resolutions of about 38 meters (125 feet) per pixel.

The MOC image has allowed scientists to determine the exact location of the Mars Pathfinder lander. Unfortunately, the image resolution is not good enough to actually see the lander--nor can any of the familiar boulders (e.g., 'Yogi') be seen at this resolution.

Using the MOC image, the landing site location has been refined by Dr. Michael Malin, Principal Investigator for the Mars Global Surveyor MOC Team and a Participating Scientist on the Mars Pathfinder mission. The images above illustrate how the landing site was located by using the 'sight lines' published by T. Parker (Jet Propulsion Laboratory, Pasadena, CA) and topographic map provided by R. Kirk (U.S. Geological Survey, Flagstaff, AZ).

Left image: MOC image 25603 subframe, shown at 15 meters (about 50 feet) per pixel resolution. Small, colored box is a topographic map of the Mars Pathfinder landing site produced by the U.S. Geological Survey (Flagstaff, AZ) from Mars Pathfinder stereographic images . Dark, heavy lines are 'sight lines' to various landmarks seen along the horizon in Mars Pathfinder camera images, measured by T. Parker and matched to features seen in Viking Orbiter images. These lines were published in Science, v. 278, p. 1746, December 5, 1997. The lighter, thinner sightlines are the same lines, adjusted to match the same features as seen in the higher resolution MOC image 25603. These lines indicate the location of the landing site to within a few hundred meters/yards. The colored box--the topographic map--has been placed at the location of the actual landing site. The lander and rover would be located at the center of the colored box. The white box shows the context of the image to the right. North is up, illumination is from the lower right.

Top right image: Location of Mars Pathfinder lander and Sojourner Rover, relative to Mars Global Surveyor MOC image obtained April 1998. The famous 'Twin Peaks'-- first seen by the lander on July 4, 1997--are shown at the lower left. The scale bar indicates distance in feet and in meters. The colored box is the topographic map of the Mars Pathfinder landing site, derived from Pathfinder camera stereoscopic images by R. Kirk and colleagues. The lander and rover were located in the center of the colored box.

Bottom right image: Location of Mars Pathfinder landing site in MOC image 25603. The lander is located in the center of the white box. The original resolution of the MOC image was about 3.3 meters (11 feet) per pixel; however, because the region was hazy at the time the picture was taken, the effective resolution is only about 5 meters (16.4 feet) per pixel. Thus, the lander and rover are too small to actually be seen in the image. The colored box, 120 m (just under 400 ft) on a side, is the topographic map of the landing site. The topographic map was made using the stereographic images taken by Mars Pathfinder in 1997. Low areas-- depressions--are blue and purple, high areas--hill--are shown as red. The range of heights is actually fairly small--a total of 4 m (about 13 ft) from dark purple to bright red. The lander is represented within the black dot at the center of the map. A preliminary version of the topographic map that is generally similar to this more refined version was published in Science, v. 278, p. 1736, December 5, 1997.

Malin Space Science Systems and the Cal

1998-01-01

236

Foraminiferal Assemblages on Sediment and Reef Rubble at Conch Reef, Florida USA  

Microsoft Academic Search

\\u000aForaminiferal Assemblages on Sediments and Reef Rubble\\u000aat Conch Reef, Florida USA\\u000aChristy Stephenson\\u000aBenthic foraminiferal assemblages are widely used to interpret responses of the benthic communities to environmental stresses. This study compares epibiotic foraminiferal assemblages, collected from reef rubble, with those from reef sediments. The study site, Conch Reef, is the site of the Aquarius Underwater Habitat research facility

Christy Michelle Stephenson

2011-01-01

237

Interface Generation and Compositional Verification in JavaPathfinder  

NASA Technical Reports Server (NTRS)

We present a novel algorithm for interface generation of software components. Given a component, our algorithm uses learning techniques to compute a permissive interface representing legal usage of the component. Unlike our previous work, this algorithm does not require knowledge about the component s environment. Furthermore, in contrast to other related approaches, our algorithm computes permissive interfaces even in the presence of non-determinism in the component. Our algorithm is implemented in the JavaPathfinder model checking framework for UML statechart components. We have also added support for automated assume-guarantee style compositional verification in JavaPathfinder, using component interfaces. We report on the application of the presented approach to the generation of interfaces for flight software components.

Giannakopoulou, Dimitra; Pasareanu, Corina

2009-01-01

238

Coral Reefs of St. Lucia, West Indies.  

National Technical Information Service (NTIS)

Coral reefs growing in the waters of St. Lucia appear to be in an early stage of development. They consist of two general types: (1) patch and platform reefs and (2) incipient fringing reefs. St. Lucia is the only coral island in the Caribbean that exhibi...

H. H. Roberts

1972-01-01

239

Assessing Coral Reef Condition: Eliciting Community Meanings  

Microsoft Academic Search

Photographs depicting a gradient of coral reef condition associated with anchor damage were assessed and described by 76 research participants. The participants were divided into two groups: those with and those without occupational experience of coral reefs. Three important meanings ascribed to coral reefs were elicited. The most important meaning was “evaluation,” whether the scenes were perceived positively or negatively.

Elizabeth A. Dinsdale; D. Mark Fenton

2006-01-01

240

40 CFR 230.44 - Coral reefs.  

Code of Federal Regulations, 2010 CFR

... 24 2009-07-01 2009-07-01 false Coral reefs. 230.44 Section 230.44 Protection of...Impacts on Special Aquatic Sites § 230.44 Coral reefs. (a) Coral reefs consist of the skeletal deposit, usually...

2009-07-01

241

40 CFR 230.44 - Coral reefs.  

Code of Federal Regulations, 2010 CFR

... 24 2010-07-01 2010-07-01 false Coral reefs. 230.44 Section 230.44 Protection of...Impacts on Special Aquatic Sites § 230.44 Coral reefs. (a) Coral reefs consist of the skeletal deposit, usually...

2010-07-01

242

Lab 1: Coral Reefs, the Human View  

NSDL National Science Digital Library

Students are introduced to coral reef ecosystems and the importance of corals to humans. Students watch the IMAX film Coral Reef Adventure to experience the human view of coral reefs through the eyes of ocean explorers and underwater filmmakers Howard and Michele Hall. The students then use microscopes to examine coral and identify its features.

243

Goldstone radar contributions to Mars Pathfinder landing safety  

NASA Technical Reports Server (NTRS)

Goldstar radar can provide topography 'profiles', statistical surface roughness, and radar images within a few degrees of the sub-Earth point. Goldstone/Very Large Array (VLA) bistatic radar observations can image the whole disk of Mars with integration times on the order of ten min before pixel smearing occurs. Data from all these radar techniques can be useful for observing the local surface conditions relating to landing safety issues for Mars Pathfinder.

Slade, Martin A.; Jurgens, R. F.

1994-01-01

244

Characteristics of the TOVS Pathfinder Path A Dataset  

Microsoft Academic Search

The TIROS (Television Infrared Observation Satellite) Operational Vertical Sounder (TOVS) Pathfinder Path A dataset is currently a 9-yr dataset, 1985-93, of global fields of surface and atmospheric parameters derived from analysis of HIRS2 and MSU data on the NOAA-9, NOAA-10, NOAA-11, and NOAA-12 polar-orbiting operational meteorological satellites. The retrieved fields include land and ocean surface skin temperature, atmospheric temperature and

J. Susskind; P. Piraino; L. Rokke; L. Iredell; A. Mehta

1997-01-01

245

Java PathFinder: A Translator From Java to Promela  

NASA Technical Reports Server (NTRS)

JAVA PATHFINDER, JPF, is a prototype translator from JAVA to PROMELA, the modeling language of the SPIN model checker. JPF is a product of a major effort by the Automated Software Engineering group at NASA Ames to make model checking technology part of the software process. Experience has shown that severe bugs can be found in final code using this technique, and that automated translation from a programming language to a modeling language like PROMELA can help reducing the effort required.

Havelund, Klaus

1999-01-01

246

A path-finding algorithm for loop-free routing  

Microsoft Academic Search

A loop-free path-finding algorithm (LPA) is presented;this is the first routing algorithm that eliminates theformation of temporary routing loops without the need forinternodal synchronization spanning multiple hops or thespecification of complete or variable-size path information.Like other previous algorithms, LPA operates by specifyingthe second-to-last hop and distance to each destination;this feature is used to ensure termination. In addition, LPAuses an inter-neighbor...

J. J. Garcia-Luna-Aceves; Shree Murthy

1997-01-01

247

JPL Experience with the Mars Pathfinder, Mission Simulation Battery  

NASA Technical Reports Server (NTRS)

A summary of the Mars Pathfinder Battery is given. The battery survived 47 days at 25 deg. C; it survived a 7 month stand at 10 to -5 deg. C; it met and exceeded 40 ampere-hour capacity for EDL; it met the 30 cycle minimum for Mars surface operation; and the project power profile for MArs surface operation does not yield energy balance.

Perrone, Dave; Ewell, Richard

1997-01-01

248

LISA and LISA Pathfinder: Gravitational Wave Observation in Space  

NASA Technical Reports Server (NTRS)

The Laser Interferometer Space Antenna (LISA) is a planned NASA-ESA gravitational wave observatory in the frequency range of 0.1 mHz--100 mHz. This observation band is inaccessible to ground-based detectors due to fluctuations in the Earth gravitational field. Gravitational wave sources for LISA include galactic binaries, mergers of supermassive black-hole binaries, extreme-mass-ratio inspirals, and cosmology backgrounds and bursts. LISA is a constellation of three spacecraft separated by 5 million km in an equilateral triangle, whose center follows the Earth in a heliocentric orbit with an orbital phase offset of 20 degrees. Challenging technology is required to ensure pure geodetic trajectories of the six onboard test masses, whose distance fluctuations will be measured by interspacecraft laser interferometers with picometer accuracy. LISA Pathfinder is an ESA-launched technology demonstration mission of key LISA subsystems such as spacecraft control with micronewton thrusters, test mass drag-free control, and precision laser interferometry between free-flying test masses. Ground testing of hardware of the Gravitational Reference Sensor and Optical Metrology subsystems of LISA Pathfinder is currently ongoing. A detailed description of the two missions and an overview of current investigations conducted by the community will be discussed. The current status in development and implementation of LISA Pathfinder pre-flight systems and latest results of the ongoing ground testing efforts will also be presented.

Guzman, Felipe

2010-01-01

249

True Color of Mars - Pathfinder Sol 10 at noon  

NASA Technical Reports Server (NTRS)

The true color of Mars based upon three filters with the sky set to aluminance of 60. The color of the Pathfinder landing site is yellowish brown with only subtle variations. These colors are identical to the measured colors of the Viking landing sites reported by Huck et al. [1977]. This image was taken near local noon on Sol 10. A description of the techniques used to generate this color image from IMP data can be found in Maki et al., 1999. Note: a calibrated output device is required accurately reproduce the correct colors.

Mars Pathfinder is the second in NASA's Discovery program of low-cost spacecraft with highly focused science goals. The Jet Propulsion Laboratory, Pasadena, CA, developed and manages the Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. JPL is an operating division of the California Institute of Technology (Caltech). The IMP was developed by the University of Arizona Lunar and Planetary Laboratory under contract to JPL. Peter Smith is the Principal Investigator.

1999-01-01

250

Chryse Planitia as a Mars Pathfinder landing site: The imperative of building on previous ground truth  

NASA Technical Reports Server (NTRS)

Based on consideration of the geological characteristics of Chryse Planitia, the requirements for Mars Pathfinder landing sites, the nature of the mission, the scale of the observations to be made, and the need to build outward from previous experience, a new mission to Chryse Planitia offers several advantages that are difficult to ignore as well as offering a low-gamble/high-return mission scenario. Considering the need to ensure a successful mission, and to ensure the continued health of planetary exploration, the reasons for a new mission to Chryse Planitia are compelling. Results of 1:500,000 mapping, operational benefits of Chryse Planitia, science benefits of Chryse Planitia, and conclusions and site recommendations are discussed.

Crumpler, Larry S.

1994-01-01

251

The Tangible Pathfinder Design of a Wayfinding Trainer for the Visually Impaired  

Microsoft Academic Search

We detail our proposal for an orientation and mobility (or wayfinding) trainer for the visually impaired—the Tangible Pathfinder. The Tangible Pathfinder allows autonomous learning of a new setting, self-assessment of the resulting cognitive map, and eventually on-site mobility assistance when physically walking through the environment. The Tangible Pathfinder integrates a tablet-like tangible user interface (TUI) which tracks a set of

Ehud Sharlin; Yoshifumi Kitamura; Darren Rorabeck; Robert Lederer; Steve Sutphen; Masafumi Takimoto; Fumio Kishino

252

Development and evaluation of the mars pathfinder inflatable airbag landing system  

Microsoft Academic Search

The entry, descent, and landing system of the Mars Pathfinder spacecraft includes a unique subsystem of airbags for impact attenuation. The airbag geometric configuration and associated landing dynamic analysis was performed by the Jet Propulsion Laboratory and Sandia National Laboratories (Mars pathfinder airbag impact attenuation system, paper AIAA-95-1552; Mars pathfinder impact, paper AIAA-95-1553). ILC Dover performed detailed design and fabrication

D. Cadogan; C. Sandy; M. Grahne

2002-01-01

253

A deep reef in deep trouble  

USGS Publications Warehouse

The well-documented degradation of shallower reefs which are often closer to land and more vulnerable to pollution, sewage and other human-related stressors has led to the suggestion that deeper, more remote offshore reefs could possibly serve as sources of coral and fish larvae to replenish the shallower reefs. Yet, the distribution, status, and ecological roles of deep (>30 m) Caribbean reefs are not well known. In this report, an observation of a deep reef which has undergone a recent extensive loss of coral cover is presented. In stark contrast to the typical pattern of coral loss in shallow reefs, the deeper corals were most affected. This report is the first description of such a pattern of coral loss on a deep reef.

Menza, C.; Kendall, M.; Rogers, C.; Miller, J.

2007-01-01

254

NOAA Coral Reef Watch: Remote Sensing and Coral Reefs  

NSDL National Science Digital Library

Developed by a fifth grade teacher, the Remote Sensing and Coral Reefs curriculum includes lesson plans, which feature links to additional information, and PowerPoint presentations. Topics discussed include altimetry, phytoplankton and ocean color, symbiosis and coral anatomy, sea surface temperature and coral bleaching, and conservation. The lesson plans can be used in sequence or by themselves.

255

The future of coral reefs  

PubMed Central

Coral reefs, with their millions of species, have changed profoundly because of the effects of people, and will continue to do so for the foreseeable future. Reefs are subject to many of the same processes that affect other human-dominated ecosystems, but some special features merit emphasis: (i) Many dominant reef builders spawn eggs and sperm into the water column, where fertilization occurs. They are thus particularly vulnerable to Allee effects, including potential extinction associated with chronic reproductive failure. (ii) The corals likely to be most resistant to the effects of habitat degradation are small, short-lived “weedy” corals that have limited dispersal capabilities at the larval stage. Habitat degradation, together with habitat fragmentation, will therefore lead to the establishment of genetically isolated clusters of inbreeding corals. (iii) Increases in average sea temperatures by as little as 1°C, a likely result of global climate change, can cause coral “bleaching” (the breakdown of coral–algal symbiosis), changes in symbiont communities, and coral death. (iv) The activities of people near reefs increase both fishing pressure and nutrient inputs. In general, these processes favor more rapidly growing competitors, often fleshy seaweeds, and may also result in explosions of predator populations. (v) Combinations of stress appear to be associated with threshold responses and ecological surprises, including devastating pathogen outbreaks. (vi) The fossil record suggests that corals as a group are more likely to suffer extinctions than some of the groups that associate with them, whose habitat requirements may be less stringent.

Knowlton, Nancy

2001-01-01

256

Quantifying Coral Reef Ecosystem Services  

EPA Science Inventory

Coral reefs have been declining during the last four decades as a result of both local and global anthropogenic stresses. Numerous research efforts to elucidate the nature, causes, magnitude, and potential remedies for the decline have led to the widely held belief that the recov...

257

The future of coral reefs  

NASA Astrophysics Data System (ADS)

Coral reefs, with their millions of species, have changed profoundly because of the effects of people, and will continue to do so for the foreseeable future. Reefs are subject to many of the same processes that affect other human-dominated ecosystems, but some special features merit emphasis: (i) Many dominant reef builders spawn eggs and sperm into the water column, where fertilization occurs. They are thus particularly vulnerable to Allee effects, including potential extinction associated with chronic reproductive failure. (ii) The corals likely to be most resistant to the effects of habitat degradation are small, short-lived "weedy" corals that have limited dispersal capabilities at the larval stage. Habitat degradation, together with habitat fragmentation, will therefore lead to the establishment of genetically isolated clusters of inbreeding corals. (iii) Increases in average sea temperatures by as little as 1°C, a likely result of global climate change, can cause coral "bleaching" (the breakdown of coral-algal symbiosis), changes in symbiont communities, and coral death. (iv) The activities of people near reefs increase both fishing pressure and nutrient inputs. In general, these processes favor more rapidly growing competitors, often fleshy seaweeds, and may also result in explosions of predator populations. (v) Combinations of stress appear to be associated with threshold responses and ecological surprises, including devastating pathogen outbreaks. (vi) The fossil record suggests that corals as a group are more likely to suffer extinctions than some of the groups that associate with them, whose habitat requirements may be less stringent.

Knowlton, Nancy

2001-05-01

258

Pathfinder: The Geospatial Intelligence Magazine - Serving the Front Line. January/February 2012, Volume 10, Number 1.  

National Technical Information Service (NTIS)

This is the January/February 2012 edition of the Pathfinder Magazine. The National Geospatial-Intelligence Agency (NGA) provides timely, relevant, and accurate geospatial intelligence in support of national security. The Pathfinder is the National Geospat...

2012-01-01

259

Pathfinder: The Geospatial Intelligence Magazine - Serving the Front Line. January/February 2010, Volume 8, Number 1.  

National Technical Information Service (NTIS)

This is the January/February 2010 edition of the Pathfinder Magazine. The National Geospatial-Intelligence Agency (NGA) provides timely, relevant, and accurate geospatial intelligence in support of national security. The Pathfinder is the National Geospat...

2010-01-01

260

Pathfinder: The Geospatial Intelligence Magazine - Serving the Front Line. March/April 2010, Volume 8, Number 2.  

National Technical Information Service (NTIS)

This is the March/April 2010 edition of the Pathfinder Magazine. The National Geospatial-Intelligence Agency (NGA) provides timely, relevant, and accurate geospatial intelligence in support of national security. The Pathfinder is the National Geospatial-I...

2010-01-01

261

Pathfinder: The Geospatial Intelligence Magazine - Serving the Front Line. May/June 2011, Volume 9, Number 3.  

National Technical Information Service (NTIS)

This is the May/June 2011 edition of the Pathfinder Magazine. The National Geospatial-Intelligence Agency (NGA) provides timely, relevant, and accurate geospatial intelligence in support of national security. The Pathfinder is the National Geospatial-Inte...

2011-01-01

262

Pathfinder: The Geospatial Intelligence Magazine Serving the Front Line, March/April 2009. Volume 7, Number 2.  

National Technical Information Service (NTIS)

The Pathfinder is the medium with which the National Geospatial- Intelligence Agency enhances and promotes public awareness and understanding of the discipline of geospatial intelligence. The Pathfinder is an authorized Department of Defense publication f...

A. Higgins C. Montenegro D. Carey D. Ellenberger S. Chang

2009-01-01

263

Retention of phytoplankton and planktonic microbes on coral reefs within the Great Barrier Reef, Australia  

NASA Astrophysics Data System (ADS)

Concentrations of phytoplankton (coccoid cychobacteria and total chlorophyll) and planktonic microrial communities (heterotropic bacteria, nanoflagellates and ciliates) were lower over leeward reef flats than over open water or reef faces, around Davies Reef and Myrmidon Reef in the central Great Barrier Reef, Australia. Concentrations of cyanobacteria, which accounted for approximately 15 50% of the carbon biomass of phytoplankton in open water, decreased from the reef face towards the leeward reef flat. Concentrations of ciliates were consistently lower at the leeward reef flat than at the reef face. For Davies Reef, the retention rates of phytoplankton and planktonic microbial communities were estimated to reach 253 gC d-1 per 1 m strip of the reef or about 0.09 gC m-2 d-1. This value is virtually equal to estimates of net community production (0.1 gC m-2 d-1). This allocthonous organic subsidy may help maintain spositive carbon balance on both Davies and Myrmidon Reefs on the Great Barrier Reef.

Ayukai, T.

1995-09-01

264

Biological models for Mesozoic reef evolution  

SciTech Connect

Throughout the Mesozoic, shallow-water carbonate ramps and platforms of the circumequatorial Tethyan Ocean were characterized by extensive development of reef ecosystems, especially during times of eustatic highstand, expansion of the Tropics, and warm equable global climates. The greatest reef development was north of the paleoequator in the Caribbean and Indo-Mediterranean provinces. These reefs and associated debris facies comprise major petroleum reservoirs, in some cases with remarkable porosity and permeability normally attributed to a combination of sedimentologic, tectonic, and diagenetic factors. The biological evolution of Mesozoic reefs also has had an important, and in some cases dominant, role in determining reservoir quality. Three major biological factors are critical to mesozoic reef-associated reservoir development: (1) the replacement/competitive displacement of coral-algal dominated, highly integrated reef ecosystems by loosely packed rudistid bivalve-dominated reef ecosystems in the Barremian-Albian; (2) the evolution of dominantly aragonitic, highly porous shells among framework-building rudistids in the middle and Late Cretaceous; and (3) competitive strategies among rudistids that effectively prevented widespread biological binding of Cretaceous reefs, leading to the production of large marginal fans that comprise major carbonate reservoirs. Detailed studies of these evolutionary trends in reef/framework development and of the distribution of different groups of bioconstructors on reefs lead to predictive modeling for primary and secondary porosity development in mesozoic carbonate reservoirs. The competitive displacement of coral-algal communities by rudistids on Cretaceous reefs was so effective that, even after Maastrichtian mass extinction of rudistids and other important groups comprising Mesozoic reef/carbonate platform ecosystems, coral-algal reef-building communities did not evolve again until the late Eocene.

Kauffman, E.G. (Univ. of Colorado, Boulder (USA))

1990-11-01

265

Battelle developing reefs to ease habitat losses  

SciTech Connect

Artificial reefs may be the answer to solving a worldwide problem of declining fish habitats, or they may only be good for creating fishing spots. Researchers at Battelle's Ocean Sciences Laboratory in Duxbury, Massachusetts, are studying artificial reefs in the Delaware River to determine if they are a solution to habitat losses in estuaries and coastal regions. [open quotes]Right now, we don't know if the fish are using the reefs simply as a grazing land, and then moving on, or if they're using the areas to colonize,[close quotes] said researcher Karen Foster. [open quotes]Ultimately, we hope to find they are colonizing.[close quotes] In 1989, Battelle researchers placed 16 prefabricated concrete reefs 45 feet deep in Delaware Bay. The reefs were placed in clusters of four, and monitoring began the following year. The federal government ordered the reefs placed in the bay as a mitigation technique for fish habitat that was lost when the river was dredged for navigational purposes. Researchers examined the reefs twice last summer. It will take five years, Foster said, before researchers can determine if the reefs are increasing the fish population. Early tests show, however, the populations of mussels, sponges, corals, and anemones increased by up to 150 percent over an area of bay bottom where the reefs were placed. Divers take crustacean samples from the reefs, and fish are caught near the reefs for examination. Researchers dissect the fish stomachs and analyze the contents to determine if they have been feeding at the reefs. [open quotes]If we find blue mussels in the stomach of the fish, that's great because we know that blue mussels are growing on the reef,[close quotes] Foster said.

Not Available

1993-04-01

266

NASA Ocean Altimeter Pathfinder Project. Report 1; Data Processing Handbook  

NASA Technical Reports Server (NTRS)

The NOAA/NASA Pathfinder program was created by the Earth Observing System (EOS) Program Office to determine how satellite-based data sets can be processed and used to study global change. The data sets are designed to be long time-sedes data processed with stable calibration and community consensus algorithms to better assist the research community. The Ocean Altimeter Pathfinder Project involves the reprocessing of all altimeter observations with a consistent set of improved algorithms, based on the results from TOPEX/POSEIDON (T/P), into easy-to-use data sets for the oceanographic community for climate research. This report describes the processing schemes used to produce a consistent data set and two of the products derived f rom these data. Other reports have been produced that: a) describe the validation of these data sets against tide gauge measurements and b) evaluate the statistical properties of the data that are relevant to climate change. The use of satellite altimetry for earth observations was proposed in the early 1960s. The first successful space based radar altimeter experiment was flown on SkyLab in 1974. The first successful satellite radar altimeter was flown aboard the Geos-3 spacecraft between 1975 and 1978. While a useful data set was collected from this mission for geophysical studies, the noise in the radar measured and incomplete global coverage precluded ft from inclusion in the Ocean Altimeter Pathfinder program. This program initiated its analysis with the Seasat mission, which was the first satellite radar altimeter flown for oceanography.

Koblinsky, C. J.; Beckley, Brian D.; Ray, Richard D.; Wang, Yan-Ming; Tsaoussi, Lucia; Brenner, Anita; Williamson, Ron

1998-01-01

267

Laser Interferometry for Gravitational Wave Observation: LISA and LISA Pathfinder  

NASA Technical Reports Server (NTRS)

The Laser Interferometer Space Antenna (LISA) is a planned NASA-ESA gravitational wave observatory in the frequency range of 0.1mHz-100mHz. This observation band is inaccessible to ground-based detectors due to the large ground motions of the Earth. Gravitational wave sources for LISA include galactic binaries, mergers of supermasive black-hole binaries, extreme-mass-ratio inspirals, and possibly from as yet unimagined sources. LISA is a constellation of three spacecraft separated by 5 million km in an equilateral triangle, whose center follows the Earth in a heliocentric orbit with an orbital phase offset oF 20 degrees. Challenging technology is required to ensure pure geodetic trajectories of the six onboard test masses, whose distance fluctuations will be measured by interspacecraft laser interferometers with picometer accuracy. LISA Pathfinder is an ESA-launched technology demonstration mission of key LISA subsystems such us spacecraft control with micro-newton thrusters, test mass drag-free control, and precision laser interferometry between free-flying test masses. Ground testing of flight hardware of the Gravitational Reference Sensor and Optical Metrology subsystems of LISA Pathfinder is currently ongoing. An introduction to laser interferometric gravitational wave detection, ground-based observatories, and a detailed description of the two missions together with an overview of current investigations conducted by the community will bc discussed. The current status in development and implementation of LISA Pathfinder pre-flight systems and latest results of the ongoing ground testing efforts will also be presented

Guzman, Felipe

2010-01-01

268

Reduction and Analysis of Meteorology Data from the Mars Pathfinder Lander  

NASA Technical Reports Server (NTRS)

Dr. James Murphy is a member of the Mars Pathfinder Atmospheric Structure Investigation Meteorology (ASI/MET) Science Team. The activities of Dr. Murphy, and his collaborators are summarized in this report, which reviews the activities in support of the analysis of the meteorology data from the Mars Pathfinder Lander.

Murphy, James R.; Bridger, Alison F. C.; Haberle, Robert M.

1998-01-01

269

Managing successful industry engagement: the Australian SKA Pathfinder experience  

NASA Astrophysics Data System (ADS)

The management of industry engagement has been one of the challenges in realising the AU$ 154M Australian Square Kilometre Array Pathfinder (ASKAP). ASKAP has evolved both in scope and scale during its aggressive delivery timeline (2007 - 2012); furthermore its relationship to the proposed international Square Kilometre Array (SKA) radio telescope has had to be carefully managed to ensure expectations remained realistic. In this paper I describe how CSIRO has navigated these challenges, forging excellent working relationships with a range of national and international companies, complimented by the establishment of a supportive national industry consortium.

Jackson, Carole

2012-09-01

270

Local Translation and mRNA Trafficking in Axon Pathfinding  

Microsoft Academic Search

Axons and their growth cones are specialized neuronal sub-compartments that possess translation machinery and have distinct\\u000a messenger RNAs (mRNAs). Several classes of mRNAs have been identified using candidate-based, as well as unbiased genome-wide-based\\u000a approaches. Axonal mRNA localization serves to regulate spatially the protein synthesis; thereby, providing axons with a high\\u000a degree of functional autonomy from the soma during axon pathfinding.

Byung C. Yoon; Krishna H. Zivraj; Christine E. Holt

271

ER-20037 LLNL eternal pathfinder wing spar design study report  

SciTech Connect

This document outlines the results of a design study performed by EDO-FSD on the LLNL Eternal Pathfinder Wing Spar/Fuel Tank. The main focus of the design study was the weight minimization of the composite wall of the mid span spar section of the aircraft. The torque, shear, moment and pressure loading requirements, as well as LLNL`s preliminary drawings, were used to develop a reduced weight mid-span spar design. The design study also encompassed details such as the pressure bulkheads, wing rod connectors, and attachment flanges.

Not Available

1994-03-01

272

The LISA PathFinder DMU Software, a Global Overview  

NASA Astrophysics Data System (ADS)

During the last 6 years, the IEEC software team has developed the Data Management Unit (DMU) software. It is a critical piece of engineering in the Lisa Pathfinder mission, in charge of the primary processing of data generated by the Phasemeter, acting also as an interface between the whole LISA Technology Package (LTP) and the On-Board Computer (OBC). It also manages and controls the diagnostics systems (Heaters, coils, magnetometers, radiation monitor, thermometers). This article briefly summarizes all the work performed, describing the complex environment built around the application generation.

Gesa, L.; Martin, V.; Conchillo, A.; Lobo, A.; Lloro, I.

2013-01-01

273

Fracture Control of the LISA Pathfinder Optical Bench  

NASA Astrophysics Data System (ADS)

The Optical Bench for LISA Pathfinder is constructed from Zerodur-a glass ceramic with low fracture resistance. The mechanism for component fracture is the growth of micro-cracks which pre-exist in the ceramic material. A programme of optical screening has been carried out to measure the size of the largest micro-cracks in high stress regions in the Zerodur blank. Results from this screening programme are presented and inferences drawn for the processing of the LISA.optical benches

Cruise, Mike; Dixon, George

274

75 FR 48934 - Coral Reef Conservation Program Implementation Guidelines  

Federal Register 2010, 2011, 2012, 2013

...100726313-0313-01] RIN 0648-ZC19 Coral Reef Conservation Program Implementation...Final Implementation Guidelines for the Coral Reef Conservation Program...Implementation Guidelines (Guidelines) for the Coral Reef Conservation Program (CRCP or...

2010-08-12

275

78 FR 67128 - Coral Reef Conservation Program; Meeting  

Federal Register 2010, 2011, 2012, 2013

...National Oceanic and Atmospheric Administration Coral Reef Conservation Program; Meeting AGENCY: Coral Reef Conservation Program, Office of Ocean...hereby given of a public meeting of the U.S. Coral Reef Task Force (USCRTF). The meeting...

2013-11-08

276

How To Build a Freshwater Artificial Reef. (Second Edition).  

National Technical Information Service (NTIS)

Updated guidelines for planning and constructing artificial reefs in freshwater are given. Reef-building methods vary depending on habitat type (i.e. lakes, ponds, and reservoirs). Artificial reefs involve different problems in rivers than in non-flowing ...

E. D. Prince O. E. Maughan P. Brouha

1977-01-01

277

DYNAMIC CHANGES IN COLORED DISSOLVED ORGANIC MATTER AND TOTAL SUSPENDED MATTER CONTROL UV EXPOSURE OF CORAL REEFS IN THE FLORIDA KEYS  

EPA Science Inventory

Variation in ultraviolet (UV) light exposure is one important environmental factor that influences the health of coral reefs. Here we present evidence that the reef tract in the Florida Keys experiences significantly higher variability in UV exposure than other surrounding coast...

278

Dynamic fragility of oceanic coral reef ecosystems  

PubMed Central

As one of the most diverse and productive ecosystems known, and one of the first ecosystems to exhibit major climate-warming impacts (coral bleaching), coral reefs have drawn much scientific attention to what may prove to be their Achilles heel, the thermal sensitivity of reef-building corals. Here we show that climate change-driven loss of live coral, and ultimately structural complexity, in the Seychelles results in local extinctions, substantial reductions in species richness, reduced taxonomic distinctness, and a loss of species within key functional groups of reef fish. The importance of deteriorating physical structure to these patterns demonstrates the longer-term impacts of bleaching on reefs and raises questions over the potential for recovery. We suggest that isolated reef systems may be more susceptible to climate change, despite escaping many of the stressors impacting continental reefs.

Graham, Nicholas A. J.; Wilson, Shaun K.; Jennings, Simon; Polunin, Nicholas V. C.; Bijoux, Jude P.; Robinson, Jan

2006-01-01

279

ReefLink Database: A decision support tool for Linking Coral Reefs and Society Through Systems Thinking  

EPA Science Inventory

Coral reefs provide the ecological foundation for productive and diverse fish and invertebrate communities that support multibillion dollar reef fishing and tourism industries. Yet reefs are threatened by growing coastal development, climate change, and over-exploitation. A key i...

280

76 FR 59377 - Amendments to the Reef Fish, Spiny Lobster, Queen Conch and Coral and Reef Associated Plants and...  

Federal Register 2010, 2011, 2012, 2013

...Fish, Spiny Lobster, Queen Conch and Coral and Reef Associated Plants and Invertebrates...Resources, Spiny Lobster, Queen Conch, and Coral and Reef Associated Plants and Invertebrates...framework procedures for spiny lobster and coral and reef associated plants and...

2011-09-26

281

Astronaut Photography of Coral Reefs  

NASA Technical Reports Server (NTRS)

Astronaut photographs of tropical coastal areas may contain information on submerged features, including coral reefs, up to depths of about 15 m in clear waters. Previous research efforts have shown that astronaut photographs can aid in estimating coral reef locations and extent on national, regional and global scales, and allow characterization of major geomorphological rim and lagoon features (Andrefouet et al. 2000, in preparation). They can be combined with traditional satellite data to help distinguish between clouds and lagoon features such as pinnacles (Andrefouet and Robinson, in review). Furthermore, astronaut photographs may provide reef scientists and managers with information on the location and extent of river plumes and sediment run off, or facilitate identification of land cover types, including mangroves (Webb et al., in press). Photographs included in the section were selected based on several criteria. The primary consideration of the editors was that the photographs represent a worldwide distribution of coral reefs, have extremely low visual interference by cloud cover, and display a spatial scale reasonable for examining reef-related features. Once photographs were selected, they were digitized from 2nd generation copies. The color and contrast were hand corrected to an approximation of natural color (required to account for spectral differences between photographs due to the color sensitivities of films used, and differences in sun angle and exposure of the photographs). None of the photographs shown here have been georeferenced to correct them to a map projection and scale. Any distortions in features due to slightly oblique look angles when the photographs were taken through spacecraft windows remain. When feasible, near vertical photographs have been rotated so that north is toward the top. An approximate scale bar and north arrow have added using distinctive features on each photograph with reference to a 1:1,000,000 scale navigation chart. Astronaut photographs provide a unique source of moderate resolution reef remote sensing data because of their global coverage and (immediate) availability in the public domain. The database of photographs can be searched an browsed online and high-resolution digital copies of photographs in this atlas can be accessed via the Website of Earth Science and Image Analysis at NASA's Johnson Space Center:

Robinson, Julie A.; Noordeloos, Marco

2001-01-01

282

Microbial photosynthesis in coral reef sediments (Heron Reef, Australia)  

NASA Astrophysics Data System (ADS)

We investigated microphytobenthic photosynthesis at four stations in the coral reef sediments at Heron Reef, Australia. The microphytobenthos was dominated by diatoms, dinoflagellates and cyanobacteria, as indicated by biomarker pigment analysis. Conspicuous algae firmly attached to the sand grains (ca. 100 ?m in diameter, surrounded by a hard transparent wall) were rich in peridinin, a marker pigment for dinoflagellates, but also showed a high diversity based on cyanobacterial 16S rDNA gene sequence analysis. Specimens of these algae that were buried below the photic zone exhibited an unexpected stimulation of respiration by light, resulting in an increase of local oxygen concentrations upon darkening. Net photosynthesis of the sediments varied between 1.9 and 8.5 mmol O 2 m -2 h -1 and was strongly correlated with Chl a content, which lay between 31 and 84 mg m -2. An estimate based on our spatially limited dataset indicates that the microphytobenthic production for the entire reef is in the order of magnitude of the production estimated for corals. Photosynthesis stimulated calcification at all investigated sites (0.2-1.0 mmol Ca 2+ m -2 h -1). The sediments of at least three stations were net calcifying. Sedimentary N 2-fixation rates (measured by acetylene reduction assays at two sites) ranged between 0.9 to 3.9 mmol N 2 m -2 h -1 and were highest in the light, indicating the importance of heterocystous cyanobacteria. In coral fingers no N 2-fixation was measurable, which stresses the importance of the sediment compartment for reef nitrogen cycling.

Werner, Ursula; Blazejak, Anna; Bird, Paul; Eickert, Gabriele; Schoon, Raphaela; Abed, Raeid M. M.; Bissett, Andrew; de Beer, Dirk

2008-03-01

283

Decadal changes in community structure in Great Barrier Reef coral reefs  

Microsoft Academic Search

CRC-supported research within the Australian Institute of Marine Science's 'Sustaining Coral Reef Biodiversity' project is investigating current status and long-term change in communities of corals and associated benthos on Great Barrier Reef (GBR) coral reefs. Potential pressures on these assemblages are deterioration in water quality, reduction in beneficial impacts of fish and invertebrate predators and grazers brought about by fishing,

E Turak; L McCook; K Fabricius; Townsville MC Qld

284

South Illinois drilling expands with reef strikes  

Microsoft Academic Search

A base map shows where reef strikes have been made in S. Illinois. These strikes have resulted in exploration activity surge featuring Marion County which opened the Salem East field in Feb. 1973, flowing from the 3,900-ft reef buildup; and (2) Washington County, where a well flowed 45 bopd from a 2,600-ft depth reef this past March. A third well

J. A. Kornfeld; M. M. Travis

1973-01-01

285

Interview with Grace Reef by Diane Dewhirst  

Microsoft Academic Search

Biographical NoteGrace Reef grew up in Portland, Maine, with her father, Norman Reef, an attorney, and her mother, Patricia Reef. In 1974, as a twelve-year-old, she was the first female Little League baseball player, having sued to integrate girls into the program. She first heard of Senator Mitchell when he ran for governor in 1974. She attended Colby College, graduating

Grace Reef

2009-01-01

286

Artificial reefs: from waste to resources  

Microsoft Academic Search

Waste materials, often referred to as “materials-of-opportunity,” have been the primary components used for constructing artificial reefs. Ships, barges, airplanes, automobiles, concrete debris, tires, and many other waste items have been disposed of at sea, with the added benefit of providing artificial reef habitat for environmental enhancement, fishing reefs, and interesting dive sites for eco-tourism. The latest development in artificial

Lee E. Harris; Benjamin J. Mostkoff; G. Zadikoff

1996-01-01

287

United States Coral Reef Task Force  

NSDL National Science Digital Library

The U.S. Coral Reef Task Force was established to lead the U.S. response to the growing global environmental crisis facing our coral reefs. This site contains information on what coral reefs are, where they can be found, how to protect them, and what the threats are. Reports on Task Force accomplishments and documents about national action plans and other information on the Task Force and their meetings is also included.

288

Holocene development of the Belize Barrier Reef  

Microsoft Academic Search

Previously, knowledge of the Holocene development of the Belize Barrier Reef (BBR)—the largest reef system in the Atlantic Ocean—was limited to one location (Carrie Bow Cay). We present new data from 11 rotary drill cores taken at 9 locations and 36 radiometric ages that indicate that the BBR was established from >8.26 to 6.68 ky BP on Pleistocene reef limestones,

Eberhard Gischler; J. Harold Hudson

2004-01-01

289

Live coral cover in the fossil record: an example from Holocene reefs of the Dominican Republic  

NASA Astrophysics Data System (ADS)

Fossil reefs hold important ecological information that can provide a prehuman baseline for understanding recent anthropogenic changes in reefs systems. The most widely used proxy for reef "health," however, is live coral cover, and this has not been quantified in the fossil record because it is difficult to establish that even adjacent corals were alive at the same time. This study uses microboring and taphonomic proxies to differentiate between live and dead corals along well-defined time surfaces in Holocene reefs of the Enriquillo Valley, Dominican Republic. At Cañada Honda, live coral cover ranged from 59 to 80% along a contemporaneous surface buried by a storm layer, and the reef, as a whole had 33-80% live cover within the branching, mixed, massive and platy zones. These values equal or exceed those in the Dominican Republic and Caribbean today or reported decades ago. The values from the western Dominican Republic provide a geologic baseline against which modern anthropogenic changes in Caribbean reefs can be considered.

Lescinsky, H.; Titus, B.; Hubbard, D.

2012-06-01

290

Update on The Ultra-Fast Flash Observatory (UFFO) Pathfinder  

NASA Astrophysics Data System (ADS)

The Ultra-Fast Flash Observatory (UFFO) uses an X/gamma and an optical/UV instrument to observe gamma-ray bursts (GRB) starting milliseconds after burst trigger and location. The X/gamma instrument, a standard coded-mask camera, locates the GRB and triggers the system. The optical/UV instrument, the Slewing Mirror Telescope (SMT), is planned to use an array of micro-electromechanical (MEMS) mirrors, with negligible moments of inertia, to steer its beam rapidly and accurately. The UFFO Pathfinder is scheduled to be launched into orbit by 2012 January. In this presentation, we give the current design of the pathfinder, with a 191 square centimeter LSO+MAPMT X/gamma detector and a 10 cm aperture SMT. We estimate that we will observe ~44 GRB per year, and detect ~10 GRB with both instruments. The UFFO will provide the most rapid optical/UV observations of GRB available thus far, and yield a sizable sample of observations of the rise-phase of GRB light curves for the first time.

Grossan, B.; Brandt, S.; Budtz-Jørgensen, C.; Castro-Tirado, A.; Kuvvetli, I.; Lim, H.; Nam, J.; Nam, K.; Panasyuk, M. I.; Park, I.; Reglero, V.; Vedenkin, N.

2011-08-01

291

NASA Ocean Altimeter Pathfinder Project. Report 2; Data Set Validation  

NASA Technical Reports Server (NTRS)

The NOAA/NASA Pathfinder program was created by the Earth Observing System (EOS) Program Office to determine how existing satellite-based data sets can be processed and used to study global change. The data sets are designed to be long time-series data processed with stable calibration and community consensus algorithms to better assist the research community. The Ocean Altimeter Pathfinder Project involves the reprocessing of all altimeter observations with a consistent set of improved algorithms, based on the results from TOPEX/POSEIDON (T/P), into easy-to-use data sets for the oceanographic community for climate research. Details are currently presented in two technical reports: Report# 1: Data Processing Handbook Report #2: Data Set Validation This report describes the validation of the data sets against a global network of high quality tide gauge measurements and provides an estimate of the error budget. The first report describes the processing schemes used to produce the geodetic consistent data set comprised of SEASAT, GEOSAT, ERS-1, TOPEX/ POSEIDON, and ERS-2 satellite observations.

Koblinsky, C. J.; Ray, Richard D.; Beckley, Brian D.; Bremmer, Anita; Tsaoussi, Lucia S.; Wang, Yan-Ming

1999-01-01

292

Mars Pathfinder and Mars Global Surveyor Outreach Compilation  

NASA Astrophysics Data System (ADS)

This videotape is a compilation of the best NASA JPL (Jet Propulsion Laboratory) videos of the Mars Pathfinder and Mars Global Surveyor missions. The mission is described using animation and narration as well as some actual footage of the entire sequence of mission events. Included within these animations are the spacecraft orbit insertion; descent to the Mars surface; deployment of the airbags and instruments; and exploration by Sojourner, the Mars rover. JPL activities at spacecraft control during significant mission events are also included at the end. The spacecraft cameras pan the surrounding Mars terrain and film Sojourner traversing the surface and inspecting rocks. A single, brief, processed image of the Cydonia region (Mars face) at an oblique angle from the Mars Global Surveyor is presented. A description of the Mars Pathfinder mission, instruments, landing and deployment process, Mars approach, spacecraft orbit insertion, rover operation are all described using computer animation. Actual color footage of Sojourner as well as a 360 deg pan of the Mars terrain surrounding the spacecraft is provided. Lower quality black and white photography depicting Sojourner traversing the Mars surface and inspecting Martian rocks also is included.

1999-09-01

293

Onondage pinnacle reefs in New York State  

SciTech Connect

Onondaga pinnacle reefs, part of the Onondaga Formation, developed in an epeiric setting of the lowermost Middle Devonian (Eifelian). The reefs were initiated as coral-crinoidal mounds in the Edgecliff Member of the formation. Whereas most Devonian reefs are composed of rugose corals. Coral is the predominant kind of fossil, followed by crinoids, brachiopods, mollusks, undifferentiated skeletal debris, and possible sponges. The initial mineralogy of the corals is inferred to have been calcite. The porosity of these reefs is almost unique among reef reservoirs. most reefs produce from secondary or diagenetic porosity; by contrast Onondaga reefs display primary intracoralline or framework porosity. Between framework builders and/or skeletal particles cryptocrystalline/microcrystalline cement fills pores. As observed in modern reefs this kind of cement resembles micrite, but probable formed as high-magnesian calcite in a high-energy setting. Syntaxial or rim cement common lines crinoid particles. Some of these pinnacle reefs, formerly gas producers, are presently under development as gas-storage reservoirs.

Friedman, G.M. [Brooklyn College and Graduate School of CUNY, Brooklyn, NY (United States)

1995-09-01

294

Coral Reef Protection: A Watershed Approach  

NSDL National Science Digital Library

This colorful, straightforward site from the Environmental Protection Agency (EPA)'s Oceans and Coastal Protection division (described in the November 25, 1998 Scout Report for Science & Engineering) outlines coral reef basic ecology and protection. About Coral Reefs provides background ecological information on coral reefs; Initiatives and Activities highlights EPA's activities but includes other US initiatives and links to symposia preceedings, factsheets, and other resources; and Related Links provides additional information on coral reef protection from the international, non-governmental (as well as federal), and educational sectors. A selection of recent news items (on the front page) rounds out the site.

Water., United S.

1998-01-01

295

Assessing Coral Reefs on a Pacific-Wide Scale Using the Microbialization Score  

PubMed Central

The majority of the world's coral reefs are in various stages of decline. While a suite of disturbances (overfishing, eutrophication, and global climate change) have been identified, the mechanism(s) of reef system decline remain elusive. Increased microbial and viral loading with higher percentages of opportunistic and specific microbial pathogens have been identified as potentially unifying features of coral reefs in decline. Due to their relative size and high per cell activity, a small change in microbial biomass may signal a large reallocation of available energy in an ecosystem; that is the microbialization of the coral reef. Our hypothesis was that human activities alter the energy budget of the reef system, specifically by altering the allocation of metabolic energy between microbes and macrobes. To determine if this is occurring on a regional scale, we calculated the basal metabolic rates for the fish and microbial communities at 99 sites on twenty-nine coral islands throughout the Pacific Ocean using previously established scaling relationships. From these metabolic rate predictions, we derived a new metric for assessing and comparing reef health called the microbialization score. The microbialization score represents the percentage of the combined fish and microbial predicted metabolic rate that is microbial. Our results demonstrate a strong positive correlation between reef microbialization scores and human impact. In contrast, microbialization scores did not significantly correlate with ocean net primary production, local chla concentrations, or the combined metabolic rate of the fish and microbial communities. These findings support the hypothesis that human activities are shifting energy to the microbes, at the expense of the macrobes. Regardless of oceanographic context, the microbialization score is a powerful metric for assessing the level of human impact a reef system is experiencing.

McDole, Tracey; Nulton, James; Barott, Katie L.; Felts, Ben; Hand, Carol; Hatay, Mark; Lee, Hochul; Nadon, Marc O.; Nosrat, Bahador; Salamon, Peter; Bailey, Barbara; Sandin, Stuart A.; Vargas-Angel, Bernardo; Youle, Merry; Zgliczynski, Brian J.; Brainard, Russell E.; Rohwer, Forest

2012-01-01

296

Pathfinder aircraft liftoff on altitude record setting flight of 71,500 feet  

NASA Technical Reports Server (NTRS)

The Pathfinder aircraft has set a new unofficial world record for high-altitude flight of over 71,500 feet for solar-powered aircraft at the U.S. Navy's Pacific Missile Range Facility, Kauai, Hawaii. Pathfinder was designed and manufactured by AeroVironment, Inc, of Simi Valley, California, and was operated by the firm under a jointly sponsored research agreement with NASA's Dryden Flight Research Center, Edwards, California. Pathfinder's record-breaking flight occurred July 7, 1997. The aircraft took off at 11:34 a.m. PDT, passed its previous record altitude of 67,350 feet at about 5:45 p.m. and then reached its new record altitude at 7 p.m. The mission ended with a perfect nighttime landing at 2:05 a.m. PDT July 8. The new record is the highest altitude ever attained by a propellor-driven aircraft. Before Pathfinder, the altitude record for propellor-driven aircraft was 67,028 feet, set by the experimental Boeing Condor remotely piloted aircraft. Pathfinder was a lightweight, solar-powered, remotely piloted flying wing aircraft used to demonstrate the use of solar power for long-duration, high-altitude flight. Its name denotes its mission as the 'Pathfinder' or first in a series of solar-powered aircraft that will be able to remain airborne for weeks or months on scientific sampling and imaging missions. Solar arrays covered most of the upper wing surface of the Pathfinder aircraft. These arrays provided up to 8,000 watts of power at high noon on a clear summer day. That power fed the aircraft's six electric motors as well as its avionics, communications, and other electrical systems. Pathfinder also had a backup battery system that could provide power for two to five hours, allowing for limited-duration flight after dark. Pathfinder flew at airspeeds of only 15 to 20 mph. Pitch control was maintained by using tiny elevators on the trailing edge of the wing while turns and yaw control were accomplished by slowing down or speeding up the motors on the outboard sections of the wing. On September 11, 1995, Pathfinder set a new altitude record for solar-powered aircraft of 50,567 feet above Edwards Air Force Base, California, on a 12-hour flight. On July 7, 1997, it set another, unofficial record of 71,500 feet at the Pacific Missile Range Facility, Kauai, Hawaii. In 1998, Pathfinder was modified into the longer-winged Pathfinder Plus configuration. (See the Pathfinder Plus photos and project description.)

1997-01-01

297

Great Barrier Reef, Queensland, Australia  

NASA Technical Reports Server (NTRS)

Along the coast of Queensland, Australia (18.0S, 147.5E), timbered foothills of the Great Dividing Range separate the semi-arid interior of Queensland from the farmlands of the coastal plains. Prominent cleared areas in the forest indicate deforestation for farm and pasture lands. Offshore, islands and the Great Barrier Reef display sand banks along the southern sides of the structures indicating a dominant southerly wind and current direction.

1991-01-01

298

Coral reef evolution on rapidly subsiding margins  

NASA Astrophysics Data System (ADS)

A series of well-developed submerged coral reefs are preserved in the Huon Gulf (Papua New Guinea) and around Hawaii. Despite different tectonics settings, both regions have experienced rapid subsidence (2-6 m/ka) over the last 500 ka. Rapid subsidence, combined with eustatic sea-level changes, is responsible for repeated drowning and backstepping of coral reefs over this period. Because we can place quantitative constraints on these systems (i.e., reef drowning age, eustatic sea-level changes, subsidence rates, accretion rates, basement substrates, and paleobathymetry), these areas represent unique natural laboratories for exploring the roles of tectonics, reef accretion, and eustatic sea-level changes in controlling the evolution of individual reefs, as well as backstepping of the entire system. A review of new and existing bathymetric, radiometric, sedimentary facies and numerical modeling data indicate that these reefs have had long, complex growth histories and that they are highly sensitive, recording drowning not only during major deglaciations, but also during high-frequency, small-amplitude interstadial and deglacial meltwater pulse events. Analysis of five generalized sedimentary facies shows that reef drowning is characterized by a distinct biological and sedimentary sequence. Observational and numerical modeling data indicate that on precessional (20 ka) and sub-orbital timescales, the rate and amplitude of eustatic sea-level changes are critical in controlling initiation, growth, drowning or sub-aerial exposure, subsequent re-initiation, and final drowning. However, over longer timescales (> 100-500 ka) continued tectonic subsidence and basement substrate morphology influence broad scale reef morphology and backstepping geometries. Drilling of these reefs will yield greatly expanded stratigraphic sections compared with similar reefs on slowly subsiding, stable and uplifting margins, and thus they represent a unique archive of sea-level and climate changes, as well as a record of the response of coral reefs to these changes over the last six glacial cycles.

Webster, Jody M.; Braga, Juan Carlos; Clague, David A.; Gallup, Christina; Hein, James R.; Potts, Donald C.; Renema, Willem; Riding, Robert; Riker-Coleman, Kristin; Silver, Eli; Wallace, Laura M.

2009-03-01

299

Coral reef evolution on rapidly subsiding margins  

USGS Publications Warehouse

A series of well-developed submerged coral reefs are preserved in the Huon Gulf (Papua New Guinea) and around Hawaii. Despite different tectonics settings, both regions have experienced rapid subsidence (2-6??m/ka) over the last 500??ka. Rapid subsidence, combined with eustatic sea-level changes, is responsible for repeated drowning and backstepping of coral reefs over this period. Because we can place quantitative constraints on these systems (i.e., reef drowning age, eustatic sea-level changes, subsidence rates, accretion rates, basement substrates, and paleobathymetry), these areas represent unique natural laboratories for exploring the roles of tectonics, reef accretion, and eustatic sea-level changes in controlling the evolution of individual reefs, as well as backstepping of the entire system. A review of new and existing bathymetric, radiometric, sedimentary facies and numerical modeling data indicate that these reefs have had long, complex growth histories and that they are highly sensitive, recording drowning not only during major deglaciations, but also during high-frequency, small-amplitude interstadial and deglacial meltwater pulse events. Analysis of five generalized sedimentary facies shows that reef drowning is characterized by a distinct biological and sedimentary sequence. Observational and numerical modeling data indicate that on precessional (20??ka) and sub-orbital timescales, the rate and amplitude of eustatic sea-level changes are critical in controlling initiation, growth, drowning or sub-aerial exposure, subsequent re-initiation, and final drowning. However, over longer timescales (> 100-500??ka) continued tectonic subsidence and basement substrate morphology influence broad scale reef morphology and backstepping geometries. Drilling of these reefs will yield greatly expanded stratigraphic sections compared with similar reefs on slowly subsiding, stable and uplifting margins, and thus they represent a unique archive of sea-level and climate changes, as well as a record of the response of coral reefs to these changes over the last six glacial cycles. ?? 2008 Elsevier B.V. All rights reserved.

Webster, J. M.; Braga, J. C.; Clague, D. A.; Gallup, C.; Hein, J. R.; Potts, D. C.; Renema, W.; Riding, R.; Riker-Coleman, K.; Silver, E.; Wallace, L. M.

2009-01-01

300

From ridge to reef—linking erosion and changing watersheds to impacts on the coral reef ecosystems of Hawai‘i and the Pacific Ocean  

USGS Publications Warehouse

Coral reef ecosystems are threatened by unprecedented watershed changes in the United States and worldwide. These ecosystems sustain fishing and tourism industries essential to the economic survival of many communities. Sediment, nutrients, and pollutants from watersheds are increasingly transported to coastal waters, where these contaminants damage corals. Although pollution from watersheds is one of many factors threatening coral survival, it is one that local people can have a profound influence on. U.S. Geological Survey scientists are using mapping, monitoring, and computer modeling to better forecast the effects of watershed changes on reef health. Working with communities in Hawai‘i and on other U.S. islands in the Pacific, they are helping to provide the science needed to make informed decisions on watershed and coral reef management.

Stock, Jonathan D.; Cochran, Susan A.; Field, Michael E.; Jacobi, James D.; Tribble, Gordon

2011-01-01

301

Coral Reef Community Composition in the Context of Disturbance History on the Great Barrier Reef, Australia  

PubMed Central

Much research on coral reefs has documented differential declines in coral and associated organisms. In order to contextualise this general degradation, research on community composition is necessary in the context of varied disturbance histories and the biological processes and physical features thought to retard or promote recovery. We conducted a spatial assessment of coral reef communities across five reefs of the central Great Barrier Reef, Australia, with known disturbance histories, and assessed patterns of coral cover and community composition related to a range of other variables thought to be important for reef dynamics. Two of the reefs had not been extensively disturbed for at least 15 years prior to the surveys. Three of the reefs had been severely impacted by crown-of-thorns starfish outbreaks and coral bleaching approximately a decade before the surveys, from which only one of them was showing signs of recovery based on independent surveys. We incorporated wave exposure (sheltered and exposed) and reef zone (slope, crest and flat) into our design, providing a comprehensive assessment of the spatial patterns in community composition on these reefs. Categorising corals into life history groupings, we document major coral community differences in the unrecovered reefs, compared to the composition and covers found on the undisturbed reefs. The recovered reef, despite having similar coral cover, had a different community composition from the undisturbed reefs, which may indicate slow successional processes, or a different natural community dominance pattern due to hydrology and other oceanographic factors. The variables that best correlated with patterns in the coral community among sites included the density of juvenile corals, herbivore fish biomass, fish species richness and the cover of macroalgae. Given increasing impacts to the Great Barrier Reef, efforts to mitigate local stressors will be imperative to encouraging coral communities to persist into the future.

Graham, Nicholas A. J.; Chong-Seng, Karen M.; Huchery, Cindy; Januchowski-Hartley, Fraser A.; Nash, Kirsty L.

2014-01-01

302

Coral reef community composition in the context of disturbance history on the great barrier reef, australia.  

PubMed

Much research on coral reefs has documented differential declines in coral and associated organisms. In order to contextualise this general degradation, research on community composition is necessary in the context of varied disturbance histories and the biological processes and physical features thought to retard or promote recovery. We conducted a spatial assessment of coral reef communities across five reefs of the central Great Barrier Reef, Australia, with known disturbance histories, and assessed patterns of coral cover and community composition related to a range of other variables thought to be important for reef dynamics. Two of the reefs had not been extensively disturbed for at least 15 years prior to the surveys. Three of the reefs had been severely impacted by crown-of-thorns starfish outbreaks and coral bleaching approximately a decade before the surveys, from which only one of them was showing signs of recovery based on independent surveys. We incorporated wave exposure (sheltered and exposed) and reef zone (slope, crest and flat) into our design, providing a comprehensive assessment of the spatial patterns in community composition on these reefs. Categorising corals into life history groupings, we document major coral community differences in the unrecovered reefs, compared to the composition and covers found on the undisturbed reefs. The recovered reef, despite having similar coral cover, had a different community composition from the undisturbed reefs, which may indicate slow successional processes, or a different natural community dominance pattern due to hydrology and other oceanographic factors. The variables that best correlated with patterns in the coral community among sites included the density of juvenile corals, herbivore fish biomass, fish species richness and the cover of macroalgae. Given increasing impacts to the Great Barrier Reef, efforts to mitigate local stressors will be imperative to encouraging coral communities to persist into the future. PMID:24983747

Graham, Nicholas A J; Chong-Seng, Karen M; Huchery, Cindy; Januchowski-Hartley, Fraser A; Nash, Kirsty L

2014-01-01

303

Evaluating coral reef health in American Samoa  

USGS Publications Warehouse

The study of coral disease has suffered from an absence of systematic approaches that are commonly used to determine causes of diseases in animals. There is a critical need to develop a standardized and portable nomenclature for coral lesions in the field and to incorporate more commonly available biomedical tools in coral disease surveys to determine the potential causes of lesions in corals. We characterized lesions in corals from American Samoa based on gross and microscopic morphology and classified them as discoloration, growth anomalies, or tissue loss. The most common microscopic finding in corals manifesting discoloration was the depletion of zooxanthellae, followed by necrosis, sometimes associated with invasive algae or fungi. The most common microscopic lesion in corals manifesting tissue loss was cell necrosis often associated with algae, fungi, or protozoa. Corals with growth anomaly had microscopic evidence of hyperplasia of gastrovascular canals, followed by necrosis associated with algae or metazoa (polychaete worms). Several species of apparently normal corals also had microscopic changes, including the presence of bacterial aggregates or crustacea in tissues. A single type of gross lesion (e.g., discoloration) could have different microscopic manifestations. This phenomenon underlines the importance of using microscopy to provide a more systematic description of coral lesions and to detect potential pathogens associated with these lesions.

Work, T. M.; Rameyer, R. A.

2005-01-01

304

Holocene development of the Belize Barrier Reef  

NASA Astrophysics Data System (ADS)

Previously, knowledge of the Holocene development of the Belize Barrier Reef (BBR)—the largest reef system in the Atlantic Ocean—was limited to one location (Carrie Bow Cay). We present new data from 11 rotary drill cores taken at 9 locations and 36 radiometric ages that indicate that the BBR was established from >8.26 to 6.68 ky BP on Pleistocene reef limestones, presumably deposited during oxygen isotope stage 5. The nonsynchronous start of Holocene reef growth was a consequence of variation in elevation of antecedent topography, largely controlled by underlying NNE-trending structures. From north to south, Pleistocene elevation decreases along these structural trends, probably reflecting differential subsidence and variations in karst topography. Reef anatomy is characterized by three facies. In order of decreasing abundance, these facies are represented by corals (mainly Acropora palmata and members of the Montastraea annularis group), by unconsolidated sand and rubble, and by well-cemented coral grainstones-rudstones. Holocene reef accumulation rates average 3.25 m/ky. The degree of reef consolidation is negatively correlated with Holocene thicknesses, indicating that slowly growing reefs are better cemented than fast growing ones. We present a Holocene sea-level curve for Belize based on 36 dates from this study and 33 dates from our previous studies in the area.

Gischler, Eberhard; Hudson, J. Harold

2004-02-01

305

Along-Track Reef Imaging System (ATRIS)  

USGS Publications Warehouse

'Along-Track Reef Imaging System (ATRIS)' describes the U.S. Geological Survey's Along-Track Reef Imaging System, a boat-based sensor package for rapidly mapping shallow water benthic environments. ATRIS acquires high resolution, color digital images that are accurately geo-located in real-time.

Brock, John; Zawada, Dave

2006-01-01

306

Sterol components of coral-reef molluscs  

Microsoft Academic Search

The sterol composition of 23 species of coral-reef molluscs from Tahiti was investigated in relation to habitat and taxonomy. The elucidation of sterol components was performed by both argentation column and gas-liquid chromatographic techniques. Coral-reef molluscs, especially gastropods, seem to be characterised by sterols rich in 24-methylcholesterol.

T. Ando; A. Kanazawa; S. Teshima; H. Miyawaki

1979-01-01

307

Northwestern Hawaiian Islands Coral Reef Ecosystem Reserve  

NSDL National Science Digital Library

This page describes the unique Northwestern Hawaiian Islands (NWHI) Ecosystem Reserve. Provides resources focused on NWHI coral reef ecosystems, and introductions to reef research, management and protection activities. Educational outreach includes: teacher workshops; student activities, and a Discovery Center in Hilo, Hawaii that features exhibits and activities for schools and the public.

2011-04-22

308

Development of contemporary Eastern Pacific coral reefs  

Microsoft Academic Search

An overview of oceanographic conditions prevailing in the tropical Eastern Pacific Ocean suggests that the entire region is environmentally marginal for coral-reef development. The principal features of this environment are a strong, permanent, shallow thermocline and an annual north-south migration of the Intertropical Convergence resulting in wet and dry seasons. Along tropical Eastern Pacific continental margins structural coral reefs are

T. F. Dana

1975-01-01

309

Oyster Reef as Habitat for Estuarine Macrofauna.  

National Technical Information Service (NTIS)

The project assessed an oyster reef as nursery habitat for juveniles of economically important penaeid shrimps, blue crab, stone crab and game fishes. It was the first investigation to compare densities of fauna on an oyster reef with those in salt marsh ...

R. Zimmerman T. Minello T. Baumer M. Castiglione

1989-01-01

310

Silurian pinnacle reefs of the Canadian Arctic  

SciTech Connect

Pinnacle reefs are commonly an attractive target for oil exploration because they are usually porous carbonate bodies entombed in impervious, deep-water shales that provide both the source and the seal for hydrocarbons. Silurian pinnacle reefs, the first described in the Canadian Arctic Archipelago, are exposed on Ellesmere and Devon Islands. Two main reef trends occur, one of early middle Llandovery to middle Ludlow age and a second of middle Ludlow to Late Silurian or Early Devonian age. Reefs of both phases contain lime mudstone cores: some are stromatactoid-rich and others consist predominantly of microbialite-rich lime mudstone or microbial boundstone. Facies sequences of both reef phases show evidence of upward-shallowing overall, but, in the older reefs, isochronous capping facies are dominated either by coral-mirian or by stromatoporoid boundstone and floatstone. This difference perhaps reflects variation in wave stress and apparent ability of a few corals,thickly encrusted by or associated with microbial boundstone and skeletal algae, to withstand greater wave energy than a stromatoporoid-coral-rich reef community. These reefs constitute one of the bright prospects of hydrocarbon exploration in rocks of the Franklinian succession. 43 refs., 9 figs.

De Freitas, T.A.; Dixon, O.A. (Univ. of Ottawa, Ontario (Canada)); Mayr, U. (Institute of Sedimentary and Petroleum Geology, Alberta (Canada))

1993-04-01

311

Reproductive ecology of Caribbean reef corals  

Microsoft Academic Search

The last decade has seen a resurgence of interest in the processes of sexual reproduction by scleractinian reef corals. Earlier investigations had focused fortuitously on brooding (planulating) species, which resulted in the general misconception that brooding was the main form of larval development of reef corals. More recent work on Indo-Pacific species has shown broadcast spawning and short annual reproductive

Alina M. Szmant

1986-01-01

312

Reefs and Learning: Education Evaluation Techniques  

ERIC Educational Resources Information Center

Marine education research designs are discussed, and student learning outcomes while monitoring a coral reef is evaluated. Changes in environmental knowledge and attitudes, ecological intention to act, and direct reef experience were investigated. Differences between student pre-test and the post-test responses were observed, and analysis is…

Stepath, Carl M.

2006-01-01

313

Northwestern Hawaiian Islands Coral Reef Ecosystem Reserve  

NSDL National Science Digital Library

Describes the unique Northwestern Hawaiian Islands (NWHI) Ecosystem Reserve. Provides resources focused on NWHI coral reef ecosystems, and introductions to reef research, management and protection activities. Educational outreach includes: teacher workshops; student activities, and a Discovery Center in Hilo, Hawaii that features exhibits and activities for schools and the public.

314

Disease of coral and coral reef fishes  

USGS Publications Warehouse

The Department of the Interior protects sensitive habitats amounting to about 3,600,000 acres of coral reefs and other submerged lands. These reefs are important ecosystems in 13 National Wildlife Refuges, 10 National Parks and in certain territorial waters such as the Wake Atoll.

Panek, Frank

2008-01-01

315

Stabilized Coal Ash Artificial Reef Studies  

Microsoft Academic Search

In 1989, an experimental stabilized coal ash reef was deployed in Poole Bay off the southern coast of the UK. Three different mixtures of pulverised fuel ash, gypsum, flue gas desulphurisation sludge and cement were used along with concrete controls. the aim was to study the environmental compatibility of the reef materials through heavy metal analyses of the blocks to

K. J. Collins; A. C. Jensen

1995-01-01

316

Numerical Modeling of Atoll Reef Harbors.  

National Technical Information Service (NTIS)

The effect of the shape of a harbor cut through a reef on mitigating waves from the deep ocean was studied using a shallow water, nonlinear, long wave code called SWAN. A significant amount of the wave energy is dissipated over the reef regardless of the ...

C. L. Mader M. Vitousek S. Lukas

1986-01-01

317

Classification of Mars Pathfinder Rock Surfaces Using Quantitative Morphologic Indices  

NASA Technical Reports Server (NTRS)

We have examined the morphology of rocks in two regions of the MPF landing site in terms of location, size and dimensions, sphericity sphericity and elongation, and have correlated this information with spectral data extracted from associated rock surfaces, with the goal of improving the likelihood of discerning between rock and rock surface types. We use four highly diverse Imager for Mars Pathfinder (IMP) images centered on Mini-Matterhorn and the Rock Garden because they are suited to demonstrate the wide morphologic variation of rocks at the site. A sampling of rocks was chosen at these locations that represented a range of shapes, textures and spectral signatures. In this initial analysis we focused upon the largest rocks that are situated in such a way as to allow easy viewing of most of the faces.

Yingst, R. A.; Haldemann, A. F. C.; Lemmon, M. T.

2003-01-01

318

Cerberus Plains: A most excellent Pathfinder landing site  

NASA Technical Reports Server (NTRS)

The Cerberus Plains in southeastern Elysium and western Amazonis cover greater than 10(exp 5) sq km, extending an east-west distance of approximately 3000 km and a north-south distance of up to 700 km near 195 deg. Crater numbers are 89 plus or minus 15 craters greater than 1 km/10(exp 6) sq km, indicating a stratigraphic age of Upper Amazonian and an absolute age of 200-500 Ma. The material forming the surface is referred to as the Cerberus Formation. The two ideas postulated about the unit's origin are fluvial and volcanic. Regardless of which interpretation is correct, the Cerberus Plains is an important candidate for a pathfinder landing site because it represents the youngest major geologic event (be it fluvial or volcanic) on Mars.

Plescia, Jeff B.

1994-01-01

319

Wheel Abrasion Experiment Metals Selection for Mars Pathfinder Mission  

NASA Technical Reports Server (NTRS)

A series of metals was examined for suitability for the Wheel Abrasion Experiment, one of ten microrover experiments of the Mars Pathfinder Mission. The seven candidate metals were: Ag, Al, Au, Cu, Ni, Pt, and W. Thin films of candidate metals from 0.1 to 1.0 micrometer thick were deposited on black anodized aluminum coupons by e-beam and resistive evaporation and chemical vapor deposition. Optical, corrosion, abrasion, and adhesion criteria were used to select Al, Ni, and Pt. A description is given of the deposition and testing of thin films, followed by a presentation of experimental data and a brief discussion of follow-on testing and flight qualification.

Hepp, Aloysius F.; Fatemi, Navid S.; Wilt, David M.; Ferguson, Dale C.; Hoffman, Richard; Hill, Maria M.; Kaloyeros, Alain E.

1996-01-01

320

Structural analyses of the JPL Mars Pathfinder impact  

NASA Astrophysics Data System (ADS)

The purpose of this paper is to demonstrate that finite element analysis can be used in the design process for high performance fabric structures. These structures exhibit extreme geometric nonlinearity; specifically, the contact and interaction of fabric surfaces with the large deformation which necessarily results from membrane structures introduces great complexity to analyses of this type. All of these features are demonstrated here in the analysis of the Jet Propulsion Laboratory (JPL) Mars Pathfinder impact onto Mars. This lander system uses airbags to envelope the lander experiment package, protecting it with large deformation upon contact. Results from the analysis show the stress in the fabric airbags, forces in the internal tendon support system, forces in the latches and hinges which allow the lander to deploy after impact, and deceleration of the lander components. All of these results provide the JPL engineers with design guidance for the success of this novel lander system.

Gwinn, Kenneth W.

321

Preliminary Results from the Mars Pathfinder ASI/MET Experiment  

NASA Technical Reports Server (NTRS)

Mars Pathfinder successfully landed in the Ares Vallis flood plain (19.3 N, 33.6 W) on July 4, 1997. The spacecraft carried a suite of instruments to record the structure of the atmosphere during the entry, descent, and landing as well as for monitoring meteorological phenomenon while on the surface. Collectively, these instruments are known as the ASI/MET experiment (Atmospheric Structure Investigation/Meteorology). In this paper we present preliminary results from the ASI/MET experiment. As of this writing, the spacecraft is healthy and continues to take daily meteorological measurements. We expect this will continue for almost one more earth year. Additional information is contained in the original extended abstract.

Haberle, R. M.; Schofield, J. T.; Crisp, D.; Barnes, J. R.; Magalhaes, J. A.; Murphy, J. R.; Seiff, A.; Wilson, G.; Larsen, S.; Young, Richard E. (Technical Monitor)

1997-01-01

322

The LISA Pathfinder interferometry—hardware and system testing  

NASA Astrophysics Data System (ADS)

Preparations for the LISA Pathfinder mission have reached an exciting stage. Tests of the engineering model (EM) of the optical metrology system have recently been completed at the Albert Einstein Institute, Hannover, and flight model tests are now underway. Significantly, they represent the first complete integration and testing of the space-qualified hardware and are the first tests on an optical system level. The results and test procedures of these campaigns will be utilized directly in the ground-based flight hardware tests, and subsequently during in-flight operations. In addition, they allow valuable testing of the data analysis methods using the MATLAB-based LTP data analysis toolbox. This paper presents an overview of the results from the EM test campaign that was successfully completed in December 2009.

Audley, H.; Danzmann, K.; García Marín, A.; Heinzel, G.; Monsky, A.; Nofrarias, M.; Steier, F.; Gerardi, D.; Gerndt, R.; Hechenblaikner, G.; Johann, U.; Luetzow-Wentzky, P.; Wand, V.; Antonucci, F.; Armano, M.; Auger, G.; Benedetti, M.; Binetruy, P.; Boatella, C.; Bogenstahl, J.; Bortoluzzi, D.; Bosetti, P.; Caleno, M.; Cavalleri, A.; Cesa, M.; Chmeissani, M.; Ciani, G.; Conchillo, A.; Congedo, G.; Cristofolini, I.; Cruise, M.; De Marchi, F.; Diaz-Aguilo, M.; Diepholz, I.; Dixon, G.; Dolesi, R.; Fauste, J.; Ferraioli, L.; Fertin, D.; Fichter, W.; Fitzsimons, E.; Freschi, M.; García Marirrodriga, C.; Gesa, L.; Gibert, F.; Giardini, D.; Grimani, C.; Grynagier, A.; Guillaume, B.; Guzmán, F.; Harrison, I.; Hewitson, M.; Hollington, D.; Hough, J.; Hoyland, D.; Hueller, M.; Huesler, J.; Jeannin, O.; Jennrich, O.; Jetzer, P.; Johlander, B.; Killow, C.; Llamas, X.; Lloro, I.; Lobo, A.; Maarschalkerweerd, R.; Madden, S.; Mance, D.; Mateos, I.; McNamara, P. W.; Mendes, J.; Mitchell, E.; Nicolini, D.; Nicolodi, D.; Pedersen, F.; Perreur-Lloyd, M.; Perreca, A.; Plagnol, E.; Prat, P.; Racca, G. D.; Rais, B.; Ramos-Castro, J.; Reiche, J.; Romera Perez, J. A.; Robertson, D.; Rozemeijer, H.; Sanjuan, J.; Schulte, M.; Shaul, D.; Stagnaro, L.; Strandmoe, S.; Sumner, T. J.; Taylor, A.; Texier, D.; Trenkel, C.; Tombolato, D.; Vitale, S.; Wanner, G.; Ward, H.; Waschke, S.; Wass, P.; Weber, W. J.; Zweifel, P.

2011-05-01

323

Mars Pathfinder Near-Field Rock Distribution Re-Evaluation  

NASA Technical Reports Server (NTRS)

We have completed analysis of a new near-field rock count at the Mars Pathfinder landing site and determined that the previously published rock count suggesting 16% cumulative fractional area (CFA) covered by rocks is incorrect. The earlier value is not so much wrong (our new CFA is 20%), as right for the wrong reason: both the old and the new CFA's are consistent with remote sensing data, however the earlier determination incorrectly calculated rock coverage using apparent width rather than average diameter. Here we present details of the new rock database and the new statistics, as well as the importance of using rock average diameter for rock population statistics. The changes to the near-field data do not affect the far-field rock statistics.

Haldemann, A. F. C.; Golombek, M. P.

2003-01-01

324

Soil-like deposits observed by Sojourner, the Pathfinder rover  

USGS Publications Warehouse

Most of the soil-like materials at the Pathfinder landing site behave like moderately dense soils on Earth with friction angles near 34°-39° and are called cloddy deposits. Cloddy deposits appear to be poorly sorted with dust-sized to granule-sized mineral or rock grains; they may contain pebbles, small rock fragments, and clods. Thin deposits of porous, compressible drifts with friction angles near 26°-28° are also present. Drifts are fine grained. Cohesions of both types of deposits are small. There may be indurated soil-like deposits and/or coated or crusted rocks. Cloddy deposits may be fluvial sediments of the Ares-Tiu floods, but other origins, such as ejecta from nearby impact craters, should be considered. Drifts are probably dusts that settled from the Martian atmosphere. Remote-sensing signatures of the deposits inferred from rover observations are consistent with those observed from orbit and Earth.

Moore, Henry J.; Bickler, Donald B.; Crisp, Joy A.; Eisen, Howard J.; Gensler, Jeffrey A.; Haldemann, Albert F. C.; Matijevic, Jacob R.; Reid, Lisa K.; Pavlics, Ferenc

1999-01-01

325

Structural analyses of the JPL Mars Pathfinder impact  

SciTech Connect

The purpose of this paper is to demonstrate that finite element analysis can be used in the design process for high performance fabric structures. These structures exhibit extreme geometric nonlinearity; specifically, the contact and interaction of fabric surfaces with the large deformation which necessarily results from membrane structures introduces great complexity to analyses of this type. All of these features are demonstrated here in the analysis of the Jet Propulsion Laboratory (JPL) Mars Pathfinder impact onto Mars. This lander system uses airbags to envelope the lander experiment package, protecting it with large deformation upon contact. Results from the analysis show the stress in the fabric airbags, forces in the internal tendon support system, forces in the latches and hinges which allow the lander to deploy after impact, and deceleration of the lander components. All of these results provide the JPL engineers with design guidance for the success of this novel lander system.

Gwinn, K.W. [Sandia National Labs., Albuquerque, NM (United States). Material and Structural Mechanics Dept.

1994-12-31

326

Prediction and Validation of Mars Pathfinder Hypersonic Aerodynamic Data Base  

NASA Technical Reports Server (NTRS)

Postflight analysis of the Mars Pathfinder hypersonic, continuum aerodynamic data base is presented. Measured data include accelerations along the body axis and axis normal directions. Comparisons of preflight simulation and measurements show good agreement. The prediction of two static instabilities associated with movement of the sonic line from the shoulder to the nose and back was confirmed by measured normal accelerations. Reconstruction of atmospheric density during entry has an uncertainty directly proportional to the uncertainty in the predicted axial coefficient. The sensitivity of the moment coefficient to freestream density, kinetic models and center-of-gravity location are examined to provide additional consistency checks of the simulation with flight data. The atmospheric density as derived from axial coefficient and measured axial accelerations falls within the range required for sonic line shift and static stability transition as independently determined from normal accelerations.

Gnoffo, Peter A.; Braun, Robert D.; Weilmuenster, K. James; Mitcheltree, Robert A.; Engelund, Walter C.; Powell, Richard W.

1998-01-01

327

Coral Reef Information System: Discover NOAA's Data  

NSDL National Science Digital Library

Part of the National Oceanic and Atmospheric Administration's Coral Reef Information System (CoRIS), this Web site is "designed to be a single point of access to NOAA coral reef information and data products, especially those derived from NOAA's Coral Reef Initiative Program." With Discover NOAA's Data, users can access information by a text search of metadata records, or by a spatial search using an Arc IMS application. The two approaches share many of the same data sets. With the text search, users may search NOAA coral reef information by title, author, keyword, etc. The map program includes "over 19,000 aerial photos, 400 preview navigational charts, tide stations, paleoclimatological studies, photo mosaics, coral reef monitoring, bleaching reports, and more." The site provides numerous help features for both search methods.

2008-06-09

328

Coral Reef Information System: Discover NOAA's Data  

NSDL National Science Digital Library

Part of the National Oceanic and Atmospheric Administration's Coral Reef Information System (CoRIS), this Web site is "designed to be a single point of access to NOAA coral reef information and data products, especially those derived from NOAA's Coral Reef Initiative Program." With Discover NOAA's Data, users can access information by a text search of metadata records, or by a spatial search using an Arc IMS application. The two approaches share many of the same data sets. With the text search, users may search NOAA coral reef information by title, author, keyword, etc. The map program includes "over 19,000 aerial photos, 400 preview navigational charts, tide stations, paleoclimatological studies, photo mosaics, coral reef monitoring, bleaching reports, and more." The site provides numerous help features for both search methods.

329

National Center for Caribbean Coral Reef Research  

NSDL National Science Digital Library

A number of research centers are concerned with the state of the world's coral reefs, and the National Center for Caribbean Coral Reef Research (NCORE) is one such center of scholarly excellence. Located at the University of Miami, NCORE is primarily concerned with "the analysis and predication of coral reef resilience". On their site, visitors can learn about some of their primary research initiatives, such as their work on the Florida reef tract and on tracking the effects of climate change on the reef communities. The general public will also find their digital map series quite useful as well. In this section, users can examine a number of complex digital maps and images that provide information about the state of coral cover around Puerto Rico, South Florida, and the Bahamas.

2006-01-06

330

Inflight magnetic characterization of the test masses onboard LISA Pathfinder  

NASA Astrophysics Data System (ADS)

Laser Interferometer Space Antenna (LISA) Pathfinder is a science and technology demonstrator of the European Space Agency within the framework of its LISA mission, the latter aiming to be the first space-borne gravitational wave observatory. The payload of LISA Pathfinder is the so-called LISA Technology Package, which is designed to measure relative accelerations between two test masses in nominal free fall. The diagnostics subsystem consists of several modules, one of which is the magnetic diagnostics unit. Its main function is the assessment of the differential acceleration noise between the test masses due to magnetic effects. This subsystem is composed of two onboard coils intended to produce controlled magnetic fields at the location of the test masses. These magnetic fields couple with the remanent magnetic moment and susceptibility and produce forces and torques on the test masses. These, in turn, produce kinematic excursions of the test masses which are sensed by the onboard interferometer. We prove that adequately processing these excursions, the magnetic properties of the test masses can be estimated using classical multiparameter estimation techniques. Moreover, we show that special processing procedures to minimize the effect of the multichannel cross-talks are needed. Finally, we demonstrate that the quality of our estimates is frequency-dependent. We also suggest that using a multiple frequency experiment, the global estimate can be obtained in such a way that the results of the magnetic experiment are more reliable. Finally, using our procedure, we compute the contribution of the magnetic noise to the total proof-mass acceleration noise.

Diaz-Aguiló, Marc; García-Berro, Enrique; Lobo, Alberto

2012-02-01

331

Climate Change, Human Impacts, and the Resilience of Coral Reefs  

Microsoft Academic Search

The diversity, frequency, and scale of human impacts on coral reefs are increasing to the extent that reefs are threatened globally. Projected increases in carbon dioxide and temperature over the next 50 years exceed the conditions under which coral reefs have flourished over the past half-million years. However, reefs will change rather than disappear entirely, with some species already showing

T. P. Hughes; A. H. Baird; D. R. Bellwood; M. Card; S. R. Connolly; C. Folke; R. Grosberg; O. Hoegh-Guldberg; J. B. C. Jackson; J. Kleypas; J. M. Lough; P. Marshall; M. Nyström; S. R. Palumbi; J. M. Pandolfi; B. Rosen; J. Roughgarden

2003-01-01

332

Edgecliff reefs - Devonian temperate water carbonate deposition  

SciTech Connect

The Middle Devonian Edgecliff Member of the Onondaga Formation in New York and Ontario, Canada, is a coral-rich, reefy,' crinoidal grainstone/packstone. The reefs contain only rare stromatoporoids and are devoid of algae, having been constructed by a fauna of mound and thicket-forming branching colonial rugosans, and large sheet favositids that populated grainstone/packstone flank beds and banks. Despite the restricted fauna, the reefs display a variety of growth patterns. Rugosan mounds range in size from 2-3 m diameter by 1 m thick, up to 230 m diameter by 15 m thick. Composite structures consist of interbedded rugosan buildups and packstone/grainstone flanks, ranging from shield-shaped reefs (240 m diameter by 6 m thick) in which the rugosans occur only as thickets, to pinnacle reefs (up to 3 km diameter by 60 m thick) in which rugosan mounds are interbedded with crinoidal flanks. Geographic distribution of these reef types and analysis of surrounding facies suggests that reef growth pattern was controlled by water depth and local rate of subsidence. Despite superfacial resemblance to modern deep water ahermatypic coral mounds and thickets, abundant coral breakage and overturning, and erosion of at least one reef core during an intermediate stage of reef growth supports a shallow water origin of these reefs. It is suggested that the Edgecliff and its reefs represent an example of Devonian cool water carbonate deposition, a hypothesis supported by a trend of increasing stromatoporoid abundance westwards across New York (in the direction of the paleo-equator).

Wolosz, T.H. (State Univ. of New York, Plattsburgh (United States))

1991-03-01

333

Impact of a Changing Climate on Coral Reefs  

NSDL National Science Digital Library

This activity is about climate change impacts on coral reefs, specifically coral bleaching. Using ReefBase - an online GIS for coral reefs - learners will access data on selected coral reefs and manipulate the data to characterize these reefs. They will then be able to apply their understanding of reef composition to identify the location and conditions necessary to sustain the coral reef ecosystem and consider the factors that produce coral bleaching and the impact of climate change. A student handout and an answer sheet are available. This activity is part of Climate Change, Wildlife and Wildlands: A Toolkit for Formal and Informal Educators.

334

The relative importance of local retention and inter-reef dispersal of neutrally buoyant material on coral reefs  

Microsoft Academic Search

Reef-scale, eddy-resolving numerical models are applied to discriminate between local trapping of neutrally buoyant passive material coming from a natal reef versus trapping of this material on reefs downstream. A hydrodynamic model is coupled with a Lagrangian (nongridded) dispersal simulation to map the movement of material such as passive larvae within and between natural reefs. To simplify the interpretation, a

Kerry P. Black

1993-01-01

335

Ecology of a Caribbean coral reef. The Porites reef-flat biotope: Part II. Plankton community with evidence for depletion  

Microsoft Academic Search

A quantitative assessment of drifting net plankton crossing a reef-flat biotope was obtained on a Caribbean coral reef. The spatial distribution and abundance of plankton were sampled to provide estimates of the removal of this potential food resource by suspension-feeding populations. Sampling was largely confined to the reef flat and adjacent waters of Laurel Cay, a flourishing coral reef present

P. W. Glynn

1973-01-01

336

The MARS pathfinder end-to-end information system: A pathfinder for the development of future NASA planetary missions  

NASA Technical Reports Server (NTRS)

The development of the Mars pathfinder is considered with emphasis on the End-to-End Information System (EEIS) development approach. The primary mission objective is to successfully develop and deliver a single flight system to the Martian surface, demonstrating entry, descent and landing. The EEIS is a set of functions distributed throughout the flight, ground and Mission Operation Systems (MOS) that inter-operate in order to control, collect, transport, process, store and analyze the uplink and downlink information flows of the mission. Coherence between the mission systems is achieved though the EEIS architecture. The key characteristics of the system are: a concurrent engineering approach for the development of flight, ground and mission operation systems; the fundamental EEIS architectural heuristics; a phased incremental EEIS development and test approach, and an EEIS design deploying flight, ground and MOS operability features, including integrated ground and flight based toolsets.

Cook, Richard A.; Kazz, Greg J.; Tai, Wallace S.

1996-01-01

337

Islands, Reefs, and a Hotspot  

NSDL National Science Digital Library

In this lesson students investigate the formation of the Hawaiian archipelago to see what geological processes produced the different physical forms seen among the Hawaiian Islands. Students will be able to describe eight stages in the formation of islands in the Hawaiian archipelago and will describe the movement of tectonic plates in the region including submarine volcanic eruptions, caldera formation, erosion, coral reef building, and atoll stages. They will also learn how a combination of hotspot activity and tectonic plate movement could produce the arrangement of seamounts observed in the Hawaiian archipelago.

Goodwin, Mel

338

The Reef Environmental Education Foundation  

NSDL National Science Digital Library

The purpose of REEF is to educate and enlist divers in the conservation of marine habitats. The main focus of this site is the Fish Survey Project, in which volunteer scuba divers and snorkelers collect and report information on marine fish populations. The data is accessible through this website, and users can both contribute data they gather and generate reports from the database. A variety of reports can be created, including lists of all species found within a specific geographic area or the distribution of a fish species or family. There is an excellent explanation of how the data can be interpreted and what the parameters in the reports represent.

2003-02-17

339

On the warm nearshore bias in Pathfinder monthly SST products over Eastern Boundary Upwelling Systems  

NASA Astrophysics Data System (ADS)

Using in situ sea surface temperature (SST) data and MODIS/TERRA SST, the monthly AVHRR Pathfinder (version 5.0 and 5.2) SST product was evaluated within the four main Eastern Boundary Upwelling Systems. A warm bias in the monthly Pathfinder data (previous to version 5.2) was systematically found during summer months in nearshore regions where high SST gradients exist. Based on a climatological average spanning 2000-2009, this summertime bias reached up to 3-5 °C in the California, Humboldt, Canary, and Benguela Upwelling Systems. This warm bias could at least partly explain the cold bias often found in numerical models of coastal upwelling. The last release of Pathfinder (version 5.2, September 2011) clearly improved the bias found on the previous Pathfinder version.

Dufois, François; Penven, Pierrick; Peter Whittle, Christo; Veitch, Jennifer

340

Web-Portal Based Approach for Knowledge Networks in Support of the Pathfinder Programme.  

National Technical Information Service (NTIS)

Technical activity program MSG-027 'Pathfinder Integration Environment' has the task of bringing the integration knowledge required to build a federation to whatever organization is charged with a federating task. In order to effectively have all federate...

A. Tolk C. D. Turnitsa G. Oehlund G. Sursal

2006-01-01

341

PATHFINDER Intelligence Software (Version 10.0) (1-3 Concurrent Users) (on Magnetic Tape).  

National Technical Information Service (NTIS)

PATHFINDER provides researchers, business analysts, and planners with computer tools and methods to analyze and gain intelligence from large amounts of textual information. Its software tools allow relationships of people, facilities, or other user-define...

1998-01-01

342

Processing and Analysis of Mars Pathfinder Science Data at JPL's Science Data Processing Section  

NASA Technical Reports Server (NTRS)

The Mars Pathfinder mission required new capabilities and adaptation of existing capabilities in order to support science analysis and flight operations requirements imposed by the in-situ nature of the mission.

LaVoie, S.; Green, W.; Runkle, A.; Alexander, D.; Andres, P.; DeJong, E.; Duxbury, E.; Freda, D.; Gorjian, Z.; Hall, J.; Hartman, F.; Levoe, S.; Lorre, J.; McAuley, J.; Suzuki, S.; Woncik, P.; Wright, J.

1998-01-01

343

Gambling on the protestants: the pathfinder fund and birth control in peru, 1958-1965.  

PubMed

Among the agencies involved in population control activities in the mid-twentieth century, none scored as many early victories in Latin America as did the Pathfinder Fund, founded by Procter & Gamble scion Clarence Gamble. This article analyzes a style in the delivery of family planning assistance in the developing world through the work of the Pathfinder Fund in Peru, the organization's hub in South America, and shows how Pathfinder personnel collaborated with local Protestant institutions. Its Protestant allies helped Pathfinder set up and manage rapid interventions such as the production of pamphlets, the smuggling of contraceptives, and the enrollment of physicians as advocates of the use of intrauterine devices. Although these rapid interventions helped quickly disseminate information and certain technologies among a fortunate few, they also weakened legitimate state agencies, neglected the monitoring of the safety of the drugs supplied, and alienated allies with their high-handed boldness. PMID:24976165

López, L Necochea

2014-01-01

344

Rigs-to-Reef Programs in the Gulf of Mexico  

Microsoft Academic Search

The Louisiana and Texas Artificial Reef Programs are the largest rigs-to-reef programs in the world. The program involves donating obsolete oil and gas structures for use as artificial reefs in lieu of on-shore removal. The National Fishing Enhancement Act of 1984 established the U.S. National Artificial Reef Plan and provided guidelines for state development of artificial reef programs. In 1986,

Mark J. Kaiser; Allan G. Pulsipher

2005-01-01

345

The Pathfinder testbed: exploring techniques for achieving precision radial velocities in the near infrared  

Microsoft Academic Search

The Penn State Pathfinder is a prototype warm fiber-fed Echelle spectrograph with a Hawaii-1 NIR detector that has already demonstrated 7-10 m\\/s radial velocity precision on integrated sunlight. The Pathfinder testbed was initially setup for the Gemini PRVS design study to enable a systematic exploration of the challenges of achieving high radial velocity precision in the near-infrared, as well as

Larry W. Ramsey; Suvrath Mahadevan; Stephen Redman; Chad Bender; Arpita Roy; Stephanie Zonak; Steinn Sigurdsson; Alex Wolszczan

2010-01-01

346

Validation of the Version 1 NOAA/NASA Pathfinder Sea Surface Temperature Data Set  

NASA Technical Reports Server (NTRS)

A high-resolution, global satellite-derived sea surface temperature (SST) data set called Pathfinder, from the Advanced Very High Resolution Radiometer (AVHRR) aboard the NOAA Polar Orbiters, is available from the Jet Propulsion Laboratory Physical Oceanography Distributed Active Archive Center (JPL PO.DAAC). Suitable for research as well as education, the Pathfinder SST data set is a result of a collaboration between the National Oceanographic and Atmospheric Administration (NOAA), the National Aeronautics and Space Administration (NASA) and investigators at several universities. NOAA and NASA are the sponsors of the Pathfinder Program, which takes advantage of currently archived Earth science data from satellites. Where necessary, satellite sensors have been intercalibrated, algorithms improved and processing procedures revised, in order to produce long time-series, global measurements of ocean, land and atmospheric properties necessary for climate research. Many Pathfinder data sets are available to researchers now, nearly a decade before the first launch of NASA's Earth Observing System (EOS). The lessons learned from the Pathfinder programs will facilitate the processing and management of terabytes of data from EOS. The Oceans component of Pathfinder has undertaken to reprocess all Global Area Coverage (GAC) data acquired by the 5-channel AVHRRs since 1981. The resultant data products are consistent and stably calibrated [Rao, 1993a, Rao, 1993b, Brown et al., 1993], Earth-gridded SST fields at a variety of spatial and temporal resolutions.

Smith, Elizabeth A.

1998-01-01

347

Miocene reef carbonates of Mariana Islands  

SciTech Connect

Miocene carbonates in the southern Mariana Islands are impressive for their lithologic diversity, thicknesses (over 250 m), and geographic extent (> 20% combined outcrop coverage over four major high islands: Guam, Rota, Tinian and Saipan). Sections are dominated either by lagoonal algal-foraminiferal wackestones and mudstones with locally abundant high-energy shelly-skeletal facies, or by rubbly to muddy, fore-reef-to-bank deposits of packstones and grainstones with highly diverse and variable biogenic clasts. Fresh to deeply weathered volcaniclastic material may comprise at least 80% of some high-energy fore-reef facies, whereas lagoonal and bank deposits usually contain less than 0.5% terrigenous material. Surprisingly, the Miocene in the Marianas lacks almost completely any reef-core facies. Several poorly developed coral-rich mounds on Saipan and localized laminated red algal buildups on Guam appear to constitute the extant reef-wall facies in the Miocene. The lack of buildups may be a matter of differential survival; it may result from headland erosion and benching associated with emergence of narrow reef tracts as has been postulated by others for south Guam. Alternatively, the authors are proposing that Miocene bathymetry and the volume of terrigenous influx militated against significant reef core formation. Radiometric age dating of these reef carbonates has proven unsuccessful because pervasive diagenesis has transformed the entire Miocene section into low-magnesium calcite with minor and occasional dolomite. Freshwater phreatic diagenesis accounts for the principal porosity variation and trace element distribution.

Siegrist, H.G. Jr.

1988-02-01

348

Management of coral reefs: we have gone wrong when neglecting active reef restoration.  

PubMed

The current best management tools employed in coral reefs worldwide do not achieve conservation objectives as coral reefs continue to degrade. Even improved reef management helps, at best, to reduce the degradation pace, whereas the worsening global changes foretell a dismal fate for coral reefs. The assertion made here is that the prospect for reefs' future is centered on omnipresent acceptance of restoration, an 'active' management instrument. A recent promising such tool is the 'gardening concept', influenced by the well-established scientific discipline of terrestrial forestation. This notion is supported by a two-step protocol. The first step entails rearing coral "seedlings", in specially designed underwater nurseries, to transplantable size, before applying the second step, out-planting into damaged areas of the nursery-farmed coral colonies. Only the establishment of large-scale nurseries and transplantation actions, together with conventional management tools, will be able to cope with extensive reef degradation on the global scale. PMID:18829052

Rinkevich, Baruch

2008-11-01

349

Uptake of picophytoplankton, bacterioplankton and virioplankton by a fringing coral reef community (Ningaloo Reef, Australia)  

Microsoft Academic Search

We examined the importance of picoplankton and virioplankton to reef trophodynamics at Ningaloo Reef, (north-western Australia),\\u000a in May and November 2008. Picophytoplankton (Prochlorococcus, Synechococcus and picoeukaryotes), bacterioplankton (inclusive of bacteria and Archaea), virioplankton and chlorophyll a (Chl a) were measured at five stations following the consistent wave-driven unidirectional mean flow path of seawater across the\\u000a reef and into the lagoon.

N. L. PattenA; A. S. J. Wyatt; R. J. Lowe; A. M. Waite

2011-01-01

350

The dynamics of benthic microbial communities at Davies Reef, central Great Barrier Reef  

NASA Astrophysics Data System (ADS)

The dynamics of benthic microbial communities were examined within different functional zones (reef crest, reef flat, lagoon) of Davies Reef, central Great Barrier Reef, in winter. Bacterial numbers did not change significantly across the reef with a mean abundance (bar x{text{ }} ± {text{ 1 SE)}} of 1.3 (±0.6) x 109 cells g-1 DW of sediment. Bacterial production, measured as thymidine incorporation into DNA, ranged from 1.2 (±0.2) to 11.6 (±1.5) mg C m-2h-1 across the reef and was significantly lower in a reef crest basin than in the other zones. Bacterial growth rates (?) across the reef (0.05 to 0.33 g-1) correlated only with sediment organic carbon and nitrogen. Protozoan and meiofaunal densities varied by an order of magnitude across the reef and correlated with one or more sediment variables but not with bacterial numbers or growth rates. Nutrient flux rates were similar to those found at other reefs in the central and southern Great Barrier Reef and are significantly lower than rates measured in temperate sand communities. In the front lagoon, bioturbation and feeding acitivity by thalassinid shrimps ( Callianassa spp.) negatively influenced microbial and meiofaunal communities with a net import of organic matter necessary to support the estimated rates of bacterial productivity. In lagoonal areas not colonized by shrimps, primary productivity (400 1100 mg C m-2d-1) from algal mats was sufficient to support bacterial growth. It is suggested that deposit-feeding macrobenthos such as thalassinid crustaceans play a major role in the tructuring and functioning of lower trophic groups (bacteria, microalgae, protozoa, meiofauna) in coral reef sedments, particularly in laggons.

Hansen, L. A.; Alongi, D. M.; Moriarty, D. J. W.; Pollard, P. C.

1987-10-01

351

Grazing pressure of herbivorous coral reef fishes on low coral-cover reefs  

Microsoft Academic Search

The impact of grazing by herbivorous fishes (Acanthuridae, Scaridae, and Pomacentridae) on low coral-cover reefs was assessed by measuring rates of benthic algal production and consumption on inshore and offshore reefs in the upper Florida Keys. Algal production rates, determined in situ with caged and uncaged experimental plates, were low (mean 1.05 g C m?2\\u000a  day?1) and similar among reef types. Algal consumption

Michelle J. Paddack; Robert K. Cowen; Su Sponaugle

2006-01-01

352

Spectral reflectance of coral reef bottom-types worldwide and implications for coral reef remote sensing  

Microsoft Academic Search

Coral reef benthic communities are mosaics of individual bottom-types that are distinguished by their taxonomic composition and functional roles in the ecosystem. Knowledge of community structure is essential to understanding many reef processes. To develop techniques for identification and mapping of reef bottom-types using remote sensing, we measured 13,100 in situ optical reflectance spectra (400–700 nm, 1-nm intervals) of 12

Eric J Hochberg; Marlin J Atkinson; Serge Andréfouët

2003-01-01

353

Contradicting Barrier Reef relationships for Darwin’s Evolution of reef types  

Microsoft Academic Search

The Darwinian progressive subsidence model for the evolution of fringing reefs, barrier reefs and atolls has been generally\\u000a accepted following the indisputable proof of subsidence provided by drilling results in the Pacific. Nonetheless, there are\\u000a data that do not fit the expectations of the model, such as the similar lagoon depths of barrier reefs and atolls as opposed\\u000a to the

Edward G. Purdy; Edward L. Winterer

2006-01-01

354

Geomorphology of unique reefs on the western Canadian shelf: sponge reefs mapped by multibeam bathymetry  

NASA Astrophysics Data System (ADS)

Multibeam imagery of siliceous sponge reefs (Hexactinellida, Hexactinosida) reveals the setting, form, and organization of five reef complexes on the western Canadian continental shelf. The reefs are built by framework skeleton sponges which trap clay-rich sediments resulting in a distinctive pattern of low intensity backscatter from the reefs that colonize more reflective glacial sediments of higher backscatter intensity. Bathymetry and backscatter maps show the distribution and form of reefs in two large complexes in the Queen Charlotte Basin (QCB) covering hundreds of km2, and three smaller reef complexes in the Georgia Basin (GB). Ridges up to 7 km long and 21 m in height, together with diversely shaped, coalescing bioherms and biostromes form the principal reef shape in the QCB whereas chains of wave-form, streamlined mounds up to 14 m in height have developed in the GB. Reef initiation is dependent on the distribution of high backscatter-intensity relict glacial surfaces, and the variation in reef complex morphology is probably the result of tidally driven, near seabed currents.

Conway, Kim W.; Barrie, J. Vaughn; Krautter, Manfred

2005-09-01

355

76 FR 63904 - Proposed Information Collection; Comment Request; Coral Reef Conservation Program Administration  

Federal Register 2010, 2011, 2012, 2013

...Information Collection; Comment Request; Coral Reef Conservation Program Administration...SUPPLEMENTARY INFORMATION: I. Abstract The Coral Reef Conservation Act of 2000 (Act) was...enacted to provide a framework for conserving coral reefs. The Coral Reef Conservation...

2011-10-14

356

Sediment and turbidity associated with offshore dredging increase coral disease prevalence on nearby reefs.  

PubMed

In recent decades, coral reef ecosystems have declined to the extent that reefs are now threatened globally. While many water quality parameters have been proposed to contribute to reef declines, little evidence exists conclusively linking specific water quality parameters with increased disease prevalence in situ. Here we report evidence from in situ coral health surveys confirming that chronic exposure to dredging-associated sediment plumes significantly increase the prevalence of white syndromes, a devastating group of globally important coral diseases. Coral health surveys were conducted along a dredging-associated sediment plume gradient to assess the relationship between sedimentation, turbidity and coral health. Reefs exposed to the highest number of days under the sediment plume (296 to 347 days) had two-fold higher levels of disease, largely driven by a 2.5-fold increase in white syndromes, and a six-fold increase in other signs of compromised coral health relative to reefs with little or no plume exposure (0 to 9 days). Multivariate modeling and ordination incorporating sediment exposure level, coral community composition and cover, predation and multiple thermal stress indices provided further confirmation that sediment plume exposure level was the main driver of elevated disease and other compromised coral health indicators. This study provides the first evidence linking dredging-associated sedimentation and turbidity with elevated coral disease prevalence in situ. Our results may help to explain observed increases in global coral disease prevalence in recent decades and suggest that minimizing sedimentation and turbidity associated with coastal development will provide an important management tool for controlling coral disease epizootics. PMID:25029525

Pollock, F Joseph; Lamb, Joleah B; Field, Stuart N; Heron, Scott F; Schaffelke, Britta; Shedrawi, George; Bourne, David G; Willis, Bette L

2014-01-01

357

Sediment and Turbidity Associated with Offshore Dredging Increase Coral Disease Prevalence on Nearby Reefs  

PubMed Central

In recent decades, coral reef ecosystems have declined to the extent that reefs are now threatened globally. While many water quality parameters have been proposed to contribute to reef declines, little evidence exists conclusively linking specific water quality parameters with increased disease prevalence in situ. Here we report evidence from in situ coral health surveys confirming that chronic exposure to dredging-associated sediment plumes significantly increase the prevalence of white syndromes, a devastating group of globally important coral diseases. Coral health surveys were conducted along a dredging-associated sediment plume gradient to assess the relationship between sedimentation, turbidity and coral health. Reefs exposed to the highest number of days under the sediment plume (296 to 347 days) had two-fold higher levels of disease, largely driven by a 2.5-fold increase in white syndromes, and a six-fold increase in other signs of compromised coral health relative to reefs with little or no plume exposure (0 to 9 days). Multivariate modeling and ordination incorporating sediment exposure level, coral community composition and cover, predation and multiple thermal stress indices provided further confirmation that sediment plume exposure level was the main driver of elevated disease and other compromised coral health indicators. This study provides the first evidence linking dredging-associated sedimentation and turbidity with elevated coral disease prevalence in situ. Our results may help to explain observed increases in global coral disease prevalence in recent decades and suggest that minimizing sedimentation and turbidity associated with coastal development will provide an important management tool for controlling coral disease epizootics.

Pollock, F. Joseph; Lamb, Joleah B.; Field, Stuart N.; Heron, Scott F.; Schaffelke, Britta; Shedrawi, George; Bourne, David G.; Willis, Bette L.

2014-01-01

358

Ocean acidification impairs vermetid reef recruitment  

NASA Astrophysics Data System (ADS)

Vermetids form reefs in sub-tropical and warm-temperate waters that protect coasts from erosion, regulate sediment transport and accumulation, serve as carbon sinks and provide habitat for other species. The gastropods that form these reefs brood encapsulated larvae; they are threatened by rapid environmental changes since their ability to disperse is very limited. We used transplant experiments along a natural CO2 gradient to assess ocean acidification effects on the reef-building gastropod Dendropoma petraeum. We found that although D. petraeum were able to reproduce and brood at elevated levels of CO2, recruitment success was adversely affected. Long-term exposure to acidified conditions predicted for the year 2100 and beyond caused shell dissolution and a significant increase in shell Mg content. Unless CO2 emissions are reduced and conservation measures taken, our results suggest these reefs are in danger of extinction within this century, with significant ecological and socioeconomic ramifications for coastal systems.

Milazzo, Marco; Rodolfo-Metalpa, Riccardo; Chan, Vera Bin San; Fine, Maoz; Alessi, Cinzia; Thiyagarajan, Vengatesen; Hall-Spencer, Jason M.; Chemello, Renato

2014-02-01

359

Ocean acidification impairs vermetid reef recruitment.  

PubMed

Vermetids form reefs in sub-tropical and warm-temperate waters that protect coasts from erosion, regulate sediment transport and accumulation, serve as carbon sinks and provide habitat for other species. The gastropods that form these reefs brood encapsulated larvae; they are threatened by rapid environmental changes since their ability to disperse is very limited. We used transplant experiments along a natural CO2 gradient to assess ocean acidification effects on the reef-building gastropod Dendropoma petraeum. We found that although D. petraeum were able to reproduce and brood at elevated levels of CO2, recruitment success was adversely affected. Long-term exposure to acidified conditions predicted for the year 2100 and beyond caused shell dissolution and a significant increase in shell Mg content. Unless CO2 emissions are reduced and conservation measures taken, our results suggest these reefs are in danger of extinction within this century, with significant ecological and socioeconomic ramifications for coastal systems. PMID:24577050

Milazzo, Marco; Rodolfo-Metalpa, Riccardo; Chan, Vera Bin San; Fine, Maoz; Alessi, Cinzia; Thiyagarajan, Vengatesen; Hall-Spencer, Jason M; Chemello, Renato

2014-01-01

360

Quaternary coral reef refugia preserved fish diversity.  

PubMed

The most prominent pattern in global marine biogeography is the biodiversity peak in the Indo-Australian Archipelago. Yet the processes that underpin this pattern are still actively debated. By reconstructing global marine paleoenvironments over the past 3 million years on the basis of sediment cores, we assessed the extent to which Quaternary climate fluctuations can explain global variation in current reef fish richness. Comparing global historical coral reef habitat availability with the present-day distribution of 6316 reef fish species, we find that distance from stable coral reef habitats during historical periods of habitat loss explains 62% of the variation in fish richness, outweighing present-day environmental factors. Our results highlight the importance of habitat persistence during periods of climate change for preserving marine biodiversity. PMID:24876495

Pellissier, Loïc; Leprieur, Fabien; Parravicini, Valeriano; Cowman, Peter F; Kulbicki, Michel; Litsios, Glenn; Olsen, Steffen M; Wisz, Mary S; Bellwood, David R; Mouillot, David

2014-05-30

361

EPA Field Manual for Coral Reef Assessments  

EPA Science Inventory

The Water Quality Research Program (WQRP) supports development of coral reef biological criteria. Research is focused on developing methods and tools to support implementation of legally defensible biological standards for maintaining biological integrity, which is protected by ...

362

Reef Ecosystem Services and Decision Support Database  

EPA Science Inventory

This scientific and management information database utilizes systems thinking to describe the linkages between decisions, human activities, and provisioning of reef ecosystem goods and services. This database provides: (1) Hierarchy of related topics - Click on topics to navigat...

363

Experiences with operations and autonomy of the Mars Pathfinder Microrover.  

NASA Astrophysics Data System (ADS)

The Microrover Flight Experiment (MFEX) is a NASA OACT (Office of Advanced Concepts and Technology) flight experiment which, integrated with the Mars Pathfinder (MPF) lander and spacecraft system, landed on Mars on July 4, 1997. In the succeeding 30 sols (1 sol = 1 Martian day), the Sojourner microrover accomplished all of its primary and extended mission objectives. After completion of the originally planned extended mission, MFEX continued to conduct a series of technology experiments, deploy its alpha proton X-ray spectrometer (APXS) on rocks and soil, and image both terrain features and the lander. This mission was conducted under the constraints of a once-per-sol opportunity for command and telemetry transmissions between the lander and Earth operators. As such, the MFEX rover was required to carry out its mission, including terrain navigation and contingency response, under supervised autonomous control. For example, goal locations were specified daily by human operators; the rover then safely traversed to these locations. During traverses, the rover autonomously detected and avoided rock, slope, and drop-off hazards, changing its path as needed before turning back towards its goal. This capability to operate in an unmodeled environment, choosing actions in response to sensor input to accomplish requested objectives, is unique among robotic space missions to date.

Mishkin, A. H.; Morrison, J. C.; Nguyen, T. T.; Stone, H. W.; Cooper, B. K.; Wilcox, B. H.

364

PathFinder Science: Keeping an Eye on Ozone  

NSDL National Science Digital Library

This site offers information and research projects that engage students in learning about ground level ozone. As part of the Pathfinder Science Collaborative Research program, students conduct scientific research on real-world topics to understand the process of science. They then submit their data so that other students and scientists around the world gain a better understanding of the issues and drive further research. Other topics include monitoring monarch butterflies, lichens, and greenhouse gases. In this forum, students determine the level of tropospheric ozone in their area and the impact on organisms in the environment, such as the milkweed plant. Background information, instructions for making ozone testing paper, and a protocol for measuring the impact of ozone on milkweed plant are provided. After collecting data, students submit it electronically and then access other students' data to develop and answer further research questions. The site also offers information on formulating questions, research methods, and data analysis along with the process and values that underlie scientific research.

365

The Scatterometer Climate Record Pathfinder: Tools for Climate Change Studies  

NASA Astrophysics Data System (ADS)

While originally designed for wind measurement over the ocean, scatterometers have proven to be very effective in monitoring land cover and ice conditions as well. Scatterometer data is being operationally used for iceberg tracking and sea ice extent mapping. The frequent, global measurements make the instrument particularly well suited for global monitoring and the long-time series of scatterometer measurements dating back to SASS provide a valuable baseline for studies of climate change. For this reason the NASA Scatterometer Climate Record Pathfinder (SCP) project is generating a climate data record from the series of historic and ongoing, and approved scatterometer missions. Selected data is currently available from the SCP at URL http://www.scp.byu.edu/ in the form of resolution-enhanced backscatter image time series. A variety of tools for analyzing the image time series have been developed. The application of QuikSCAT data to climate change in Greenland and sea ice motion in the Arctic is illustrated. By comparing QuikSCAT with NSCAT and SASS data, long-term scatterometer-observed changes in Greenland are related to annual variations in melt extent and snow accumulation. Qu ikSCAT sampling enables high spatial resolution evaluation of the diurnal melt cycle. We demonstrate the value of the scatterometer data to augment passive microwave measurements by using PCA. The scatterometer data plays a key role in helping to discriminate physical changes in the Greenland firn from surface temperature effects.

Long, D. G.; Jensen, M. A.

2001-12-01

366

Antenna Deployment for a Pathfinder Lunar Radio Observatory  

NASA Technical Reports Server (NTRS)

A first step in the development of a large radio observatory on the moon for cosmological or other astrophysical and planetary goals is to deploy a few antennas as a pathfinder mission. In this presentation, we describe a mechanism being developed to deploy such antennas from a small craft, such as a Google Lunar X-prize lander. The antenna concept is to deposit antennas and leads on a polyimide film, such as Kapton, and to unroll the film on the lunar surface. The deployment technique utilized is to launch an anchor which pulls a double line from a reel at the spacecraft. Subsequently, the anchor is set by catching on the surface or collecting sufficient regolith. A motor then pulls in one end of the line, pulling the film off of its roller onto the lunar surface. Detection of a low frequency cutoff of the galactic radio background or of solar radio bursts by such a system would determine the maximum lunar ionospheric density at the time of measurement. The current design and testing, including videos of the deployment, will be presented. These activities are funded in part by the NASA Lunar Science Institute as an activity of the Lunar University Network for Astrophysical Research (LUNAR) consortium. Part of this research was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration.

MacDowall, Robert J.; Minetto, F. A.; Lazio, T. W.; Jones, D. L.; Kasper, J. C.; Burns, J. O.; Stewart, K. P.; Weiler, K. W.

2012-01-01

367

The NASA Cold Land Processes Pathfinder Mission (CLPP)  

NASA Technical Reports Server (NTRS)

The Cold Land Processes Pathfinder (CLPP) mission concept has been developed to measure hydrologic properties of the Cryosphere. The science driver for the mission is to understand the variability of global water cycling and its consequences for local water resources and climate. The CLPP mission is designed to reduce uncertainty of cold-region precipitation, storage, controls, and feedbacks to the land, atmosphere, and ocean, which in turn will improve prediction of future changes in water cycle dynamics. It will provide the first high-resolution global measurements of Earth's changing snow conditions to: 1) quantify the variability of processes in cold regions, 2) improve understanding of past changes, and 3) enable breakthroughs in prediction of future water resources, weather, and climate. The CLPP concept consists of active (C- and Ku-band) and passive (K- and Ka-band) microwave sensors (with high and moderate spatial resolution respectively) to observe snow water equivalent and snow wetness at local process scales. The CLPP global sampling framework provides necessary capability to relate observed local scale snow characteristics to atmospheric forcings, improve predictive models operating at multiple scales, and to tie the short-term CLPP record to the long-term low-resolution remote sensing climate record of global snow properties.

Cline, D.; McDonald, K.; Kim, E.

2004-01-01

368

Slope Morphology of Twin Peaks, Mars Pathfinder Landing Site  

NASA Astrophysics Data System (ADS)

Development of slope form over time has long been a concern of geomorphologists, although recently this concern has been moved to slope processes rather than form. There are two basic approaches. The first is theoretical, involving modeling of different types and rates of processes, and calculation of results in terms of slope evolution over time. Comparisons with real-life slopes can follow this approach [1], [2]. The second, inductive, approach involves field measurements to test ideas about slope evolution starting from the assumption that observed slopes represent different stages of an essentially similar evolution [3]. Space is substituted for time, and a number of slopes, assumed to be of increasing age, are measured and placed in an evolutionary sequence (e.g. [4], [5], [6]). [5] showed that slope angles are modally distributed, with the modal angles controlled by the materials (regolith) of which the slopes are formed, and by the processes operating on them. Data can be obtained directly from field work or from digital elevation models (DEM) derived from remote sensing investigations [7]. DEMs are particularly useful to study inaccessible planets, such as Mars, where on site observations are restricted to only a few landing sites. Here we present a study of slopes on the Twin Peaks, two small hills located 780 m north and 910 m south of the Mars Pathfinder landing site at the mouth of the Ares and Tiu flood channels. The presence of streamlined hills, jumbled surfaces and conglomerates suggested the region was modified by massive flooding 1.8 - 3.5 billion years ago [8], [9]. The streamlined forms and terraces of the Twin Peaks were taken to indicate catastrophic flood conditions that were believed to be prevalent in the area [8]. It was also suggested that the northernmost peak was topped by floodwater, causing its flatter appearance. Other researchers postulated alternative geomorphological origins for the features observed at the Pathfinder landing site. Processes such as ice flow or deposition were proposed as being the principal cause of most of observed features, by analogy with similar features observed on Earth [10]. Here we propose that the slopes on the Twin Peaks may provide an indication of the processes that shaped them after they were formed. This work shows the results of a detailed morphometric analysis of slopes on the southernmost peak, conducted to gain a greater understanding of past and present slope processes at work at the Pathfinder landing site. The southern Twin Peak is a conical hill rising 38 m above the local terrain. A portion of the Pathfinder super panorama was used to analyse the hill-slope morphology. The camera horizon was used as a baseline and all slope angles were measured from this. The hill comprises four separate regions including the top of the hill, which is convex in shape. The convex nature of the hilltop is a common if not ubiquitous feature of hills regardless of their origin. It is related to the creep processes that frequently dominate the tops of hill slopes. In this case it was probably caused by heating and cooling during the Martian diurnal cycle, by the action of soil water, or a combination of both. All slope sections were observed to be similar in length. The slopes nearest the hill top measure 21? and 22.5? respectively on the north and south sides of the Southern Twin Peak. Mid way down the hill the next sequence of slopes have north and south angles of 9? and 15? respectively. Shallow end-slopes measure 4? and 5? north and south respectively. Similarity of slope angles and lengths indicates symmetry, suggesting that the rocks are the same all around the hill. Our analysis suggests that slope angles are controlled by a combination of the materials of which they are formed and the processes that are operating on them. Their primarily symmetrical outlook indicates no structural control, suggesting that the hill is formed by flat-lying or massive homogeneous rocks. This being the case, slope morphology results from shallow processes related to mass was

Hobbs, Steven; Paine, Colin; Clarke, Jon; Caprarelli, Graziella

2010-05-01

369

The Earth System Science Pathfinder Orbiting Carbon Observatory (OCO) Mission  

NASA Technical Reports Server (NTRS)

A viewgraph presentation describing the Earth System Science Pathfinder Orbiting Carbon Observatory (OCO) Mission is shown. The contents include: 1) Why CO2?; 2) What Processes Control CO2 Sinks?; 3) OCO Science Team; 4) Space-Based Measurements of CO2; 5) Driving Requirement: Precise, Bias-Free Global Measurements; 6) Making Precise CO2 Measurements from Space; 7) OCO Spatial Sampling Strategy; 8) OCO Observing Modes; 9) Implementation Approach; 10) The OCO Instrument; 11) The OCO Spacecraft; 12) OCO Will Fly in the A-Train; 13) Validation Program Ensures Accuracy and Minimizes Spatially Coherent Biases; 14) Can OCO Provide the Required Precision?; 15) O2 Column Retrievals with Ground-based FTS; 16) X(sub CO2) Retrieval Simulations; 17) Impact of Albedo and Aerosol Uncertainty on X(sub CO2) Retrievals; 18) Carbon Cycle Modeling Studies: Seasonal Cycle; 19) Carbon Cycle Modeling Studies: The North-South Gradient in CO2; 20) Carbon Cycle Modeling Studies: Effect of Diurnal Biases; 21) Project Status and Schedule; and 22) Summary.

Crisp, David

2003-01-01

370

Mineralogy, composition, and alteration of Mars Pathfinder rocks and soils: Evidence from multispectral, elemental, and magnetic data on terrestrial analogue, SNC meteorite, and Pathfinder samples  

Microsoft Academic Search

Major element, multispectral, and magnetic properties data were obtained at Ares Vallis during the Mars Pathfinder mission. To understand the compositional, mineralogical, and process implications of these data, we obtained major element, mineralogical, and magnetic data for well-crystalline and nanophase ferric minerals, terrestrial analogue samples with known geologic context, and SNC meteorites. Analogue samples include unaltered, palagonitic, and sulfatetic tephra

Richard V. Morris; Tad D. Shelfer; Andreas C. Scheinost; Nancy W. Hinman; George Furniss; Janice L. Bishop; Douglas W. Ming; Carlton C. Allen; Daniel T. Britt

2000-01-01

371

Explore coral reefs around the world  

NSDL National Science Digital Library

This Earth science resource uses a world map to show students the locations of five coral reefs. Students are instructed to toggle between maps coded according to ocean depth or water temperature to determine the conditions required for coral growth. Each reef is indicated by a red dot that students click on to view a photograph and to read additional information. Copyright 2005 Eisenhower National Clearinghouse

Education, Terc. C.; Littell, Mcdougal

2003-01-01

372

Remote Sensing of Coral Reef Processes  

Microsoft Academic Search

\\u000a Digital remote sensing of coral reefs dates to the first Landsat mission of the mid-1970s. Early studies utilized moderate-spatial-resolution\\u000a satellite broadband multispectral image data and focused on reef geomorphology. Technological advances have since led to development\\u000a of airborne narrow-band hyperspectral sensors, airborne hydrographic lidar systems, and commercial high-spatial-resolution\\u000a satellite broadband multispectral imagers. High quality remote sensing data have become widely

Eric J. Hochberg

373

Miocene reef carbonates of Mariana Islands  

SciTech Connect

Miocene carbonates in the southern Mariana Islands are impressive for their lithologic diversity, thicknesses (over 250 m), and geographic extend (>20% combined outcrop coverage over four major high islands: Guam, Rota, Tinian and Saipan). Sections are dominated either by lagoonal algal-foraminiferal wackestones and mudstones with locally abundant high-energy shelly-skeletal facies, or by rubbly to muddy, fore-reef-to-bank deposits of packstones and grainstones with highly diverse and variable biogenic clasts. Fresh to deeply weathered volcaniclastic material may comprise at least 80% of some high-energy fore-reef facies, whereas lagoonal and bank deposits usually contain less than 0.5% terrigenous material. Surprisingly, the Miocene in the Marianas lacks almost completely any reef-core facies. Several poorly developed coral-rich mounds on Saipan and localized laminated red algal buildups on Guam appear to constitute the extant reef-wall facies in the Miocene. The lack of buildups may be a matter of differential survival; it may result from headland erosion and benching associated with emergency of narrow reef tracts as has been postulated by others for south Guam. Radiometric age dating of these reef carbonates has proven unsuccessful because pervasive diagenesis has transformed the entire Miocene section into low-magnesium calcite with minor and occasional dolomite. Freshwater phreatic diagenesis accounts for the principal porosity variation and trace element distribution.

Siegrist, H.G. Jr.

1988-01-01

374

ReefSAM - Reef Sedimentary Accretion Model: A new 3D coral reef evolution model/simulator  

NASA Astrophysics Data System (ADS)

Coral reefs show characteristic morphological patterns (e.g. coral dominated margins with detrital carbonate dominated lagoons/back-reef) and temporal development (e.g. Hopley et al. 2007). While the processes which lead to predictable patterns on a range of scales have been discussed qualitatively, a full quantitative understanding of the range of processes and parameters involved requires modelling. Previous attempts to model complex Holocene reef systems (i.e. One Tree Reef, GBR - Barrett and Webster 2012) using a carbonate stratigraphic forward model (Carbonate3D - Warrlich et al. 2002) identified a number of important but unsimulated processes and potential model improvements. ReefSAM has been written from scratch in Matlab using these findings and experiences from using Carbonate3D. It simulates coralgal accretion and carbonate sand production and transport. Specific improvements include: 1. a more complex hydrodynamic model based on wave refraction and incorporating vertical (depth) and lateral (substrate dependent) variations in transport energy and erosion. 2. a complex reef growth model incorporating depth, wave energy/turbidity and substrate composition. 3. Paleo-water depth, paleo-wave energy and bio-zone (combination of paleo-water depth and wave energy) model outputs allowing coralgal habitat changes through time and space to be simulated and compared to observational data. The model is compared to the well studied One Tree Reef - tests similar to those undertaken in Barrett and Webster 2012 with Carbonate3D are presented. Model development coincides with plans for further intensive drilling at One Tree Reef (mid 2013) providing an opportunity to test the model predictively. The model is still in active development. References: Barrett, S.J., Webster, J.M.,2012. Holocene evolution of the Great Barrier Reef: Insights from 3D numerical modelling. Sedimentary Geology 265-266, 56-71. Warrlich, G.M.D., Waltham, D.A., Bosence D.W.J., 2002. Quantifying the sequence stratigraphy and drowning mechanisms of atolls using a new 3-D forward modelling program (CARBONATE 3D). Basin Research 14, 379-400. Hopley, D., Smithers, S.G., Parnell, K.E., 2007. The geomorphology of the Great Barrier Reef. Cambridge.

Barrett, Samuel; Webster, Jody

2013-04-01

375

Grazing pressure of herbivorous coral reef fishes on low coral-cover reefs  

NASA Astrophysics Data System (ADS)

The impact of grazing by herbivorous fishes (Acanthuridae, Scaridae, and Pomacentridae) on low coral-cover reefs was assessed by measuring rates of benthic algal production and consumption on inshore and offshore reefs in the upper Florida Keys. Algal production rates, determined in situ with caged and uncaged experimental plates, were low (mean 1.05gCm-2 day-1) and similar among reef types. Algal consumption rates were estimated using two different models, a detailed model incorporating fish bite rates and algal yield-per-bite for one species extrapolated to a guild-wide value, and a general regression relating fish biomass to algal consumption. Algal consumption differed among reef types: a majority of algal production was consumed on offshore reefs (55-100%), whereas consumption on inshore patch reefs was 31-51%. Spatial variation in algal consumption was driven by differences in herbivorous fish species composition, density, and size-structure among reef types. Algal consumption rates also varied temporally due to seasonal declines in bite rates and intermittent presence of large-bodied, vagile, schooling species. Spatial coherence of benthic community structure and temporal stability of algal turf over 3 years suggests that grazing intensity is currently sufficient to limit further spread of macroalgal cover on these low coral-cover reefs, but not to exclude it from the system.

Paddack, Michelle J.; Cowen, Robert K.; Sponaugle, Su

2006-08-01

376

Changes in the reef-coral community of Carysfort reef, Key Largo, Florida: 1974 to 1982  

Microsoft Academic Search

Data from 21 permanently marked line transects showed that significant changes occurred in the composition of the reef coral community on Carysfort Reef between 1975 and 1982–1983. Coral populations between 0 and 9 m show signs of change due primarily to physical disturbance while corals living between 10 and 21 m have decreased in abundance as a result of sedimentation

Phillip Dustan; John C. Halas

1987-01-01

377

Pathfinder ground preparations prior to altitude record setting flight of 71,500 feet  

NASA Technical Reports Server (NTRS)

Technicians make final adjustments on the solar-powered Pathfinder remotely piloted research aircraft prior to the craft's taking off on a flight which established a new unofficial world's altitude record for both propellor-driven and solar-powered aircraft. The new record of more than 71,500 feet was set during a 14 1/2-hour flight July 7, 1997, from the U.S. Navy's Pacific Missile Range Facility (PMRF) at Barking Sands, Kauai, Hawaii. The new altitude record is subject to verification by the National Aeronautics Association. The Pathfinder took off at 8:34 a.m. HDT, passed its previous record altitude of 67,350 feet about 2:45 p.m., and then reached its new mark at about 4 p.m. Controllers on the ground then initiated a slow decent, and Pathfinder landed seven hours later at 11:05 p.m. HDT. The experimental Boeing Condor remotely-piloted aircraft had held the previous record for propellor-driven craft of 67,028 feet. The Pathfinder had exceeded that height on a previous flight on June 9, 1997, but not by a large enough margin to be considered a new record. Pathfinder was a lightweight, solar-powered, remotely piloted flying wing aircraft used to demonstrate the use of solar power for long-duration, high-altitude flight. Its name denotes its mission as the 'Pathfinder' or first in a series of solar-powered aircraft that will be able to remain airborne for weeks or months on scientific sampling and imaging missions. Solar arrays covered most of the upper wing surface of the Pathfinder aircraft. These arrays provided up to 8,000 watts of power at high noon on a clear summer day. That power fed the aircraft's six electric motors as well as its avionics, communications, and other electrical systems. Pathfinder also had a backup battery system that could provide power for two to five hours, allowing for limited-duration flight after dark. Pathfinder flew at airspeeds of only 15 to 20 mph. Pitch control was maintained by using tiny elevators on the trailing edge of the wing while turns and yaw control were accomplished by slowing down or speeding up the motors on the outboard sections of the wing. On September 11, 1995, Pathfinder set a new altitude record for solar-powered aircraft of 50,567 feet above Edwards Air Force Base, California, on a 12-hour flight. On July 7, 1997, it set another, unofficial record of 71,500 feet at the Pacific Missile Range Facility, Kauai, Hawaii. In 1998, Pathfinder was modified into the longer-winged Pathfinder Plus configuration. (See the Pathfinder Plus photos and project description.)

1997-01-01

378

Spatial variability of the biogeochemical composition of surface sediments in an insular coral reef ecosystem: Moorea, French Polynesia  

NASA Astrophysics Data System (ADS)

The spatial variability of the biogeochemical composition of surface sediments was investigated around Moorea, French Polynesia. This study complements other ones conducted in Moorea to assess coral reef "health". A total of 35 stations were sampled at four sites around the island, on the following geomorphological units: fringing reef of the bays, fringing reef of the lagoon, channel, barrier reef, pass, sandy slope, bay bottom. We found strong spatial heterogeneity in the biogeochemical composition of surface sediments. The multivariate analyses (PCA and clustering) distinguished four major sediment types around Moorea, and a gradient between the bayheads and the bay entrances. The first type corresponds to the inner half bay bottoms, and clearly represents the "terrigeneous" influence. This terrigeneous sediment type was mainly characterised by a clear deficit in carbonates and, conversely, by an enrichment in organic compounds (organic carbon (OC), nitrogen (N), as well as total amino acids (AA) and carbohydrates (CH) in mg g -1) that were highly degraded. Two other sediment types were influenced by the carbonated reef system. They were highly carbonated (inorganic carbon (IC) around 11%; i.e., carbonates around 90%), and showed low organic compound concentrations. They were also characterised by high hydrolysable organic carbon (HOC) concentrations. These two "reef-characteristic" sediment types can be distinguished by their N concentrations and C/N ratio. The fourth type represents a transition between "reef-characteristic" and "terrigeneous" sediment types. Our results showed that HOC, total AA and CH, examined for the first time in coral reef ecosystems, were reliable descriptors for spatial variability surveys, together with the more 'classical' descriptors: IC, OC and N.

Schrimm, M.; Buscail, R.; Adjeroud, M.

2004-07-01

379

The Pathfinder testbed: exploring techniques for achieving precision radial velocities in the near infrared  

NASA Astrophysics Data System (ADS)

The Penn State Pathfinder is a prototype warm fiber-fed Echelle spectrograph with a Hawaii-1 NIR detector that has already demonstrated 7-10 m/s radial velocity precision on integrated sunlight. The Pathfinder testbed was initially setup for the Gemini PRVS design study to enable a systematic exploration of the challenges of achieving high radial velocity precision in the near-infrared, as well as to test possible solutions to these calibration challenges. The current version of the Pathfinder has an R3 echelle grating, and delivers a resolution of R~50,000 in the Y, J or H bands of the spectrum. We will discuss the on sky-performance of the Pathfinder during an engineering test run at the Hobby Eberly Telescope as well the results of velocity observations of M dwarfs. We will also discuss the unique calibration techniques we have explored, like Uranium-Neon hollow cathode lamps, notch filter, and modal noise mitigation to enable high precision radial velocity observation in the NIR. The Pathfinder is a prototype testbed precursor of a cooled high-resolution NIR spectrograph capable of high radial velocity precision and of finding low mass planets around mid-late M dwarfs.

Ramsey, Larry W.; Mahadevan, Suvrath; Redman, Stephen; Bender, Chad; Roy, Arpita; Zonak, Stephanie; Sigurdsson, Steinn; Wolszczan, Alex

2010-07-01

380

The structure of Mediterranean rocky reef ecosystems across environmental and human gradients, and conservation implications  

USGS Publications Warehouse

Historical exploitation of the Mediterranean Sea and the absence of rigorous baselines makes it difficult to evaluate the current health of the marine ecosystems and the efficacy of conservation actions at the ecosystem level. Here we establish the first current baseline and gradient of ecosystem structure of nearshore rocky reefs at the Mediterranean scale. We conducted underwater surveys in 14 marine protected areas and 18 open access sites across the Mediterranean, and across a 31-fold range of fish biomass (from 3.8 to 118 g m-2). Our data showed remarkable variation in the structure of rocky reef ecosystems. Multivariate analysis showed three alternative community states: (1) large fish biomass and reefs dominated by non-canopy algae, (2) lower fish biomass but abundant native algal canopies and suspension feeders, and (3) low fish biomass and extensive barrens, with areas covered by turf algae. Our results suggest that the healthiest shallow rocky reef ecosystems in the Mediterranean have both large fish and algal biomass. Protection level and primary production were the only variables significantly correlated to community biomass structure. Fish biomass was significantly larger in well-enforced no-take marine reserves, but there were no significant differences between multi-use marine protected areas (which allow some fishing) and open access areas at the regional scale. The gradients reported here represent a trajectory of degradation that can be used to assess the health of any similar habitat in the Mediterranean, and to evaluate the efficacy of marine protected areas.

Sala, Enric; Ballesteros, Enric; Dendrinos, Panagiotis; Di Franco, Antonio; Ferretti, Francesco; Foley, David; Fraschetti, Simonetta; Friedlander, Alan; Garrabou, Joaquim; Guclusoy, Harun; Guidetti, Paolo; Halpern, Benjamin S.; Hereu, Bernat; Karamanlidis, Alexandros A.; Kizilkaya, Zafer; Macpherson, Enrique; Mangialajo, Luisa; Mariani, Simone; Micheli, Fiorenza; Pais, Antonio; Riser, Kristin; Rosenberg, Andrew A.; Sales, Marta; Selkoe, Kimberly A.; Starr, Rick; Tomas, Fiona; Zabala, Mikel

2012-01-01

381

Variation in depth of whitetip reef sharks: does provisioning ecotourism change their behaviour?  

NASA Astrophysics Data System (ADS)

In the dive tourism industry, shark provisioning has become increasingly popular in many places around the world. It is therefore important to determine the impacts that provisioning may have on shark behaviour. In this study, eight adult whitetip reef sharks Triaenodon obesus were tagged with time-depth recorders at Osprey Reef in the Coral Sea, Australia. Tags collected time and depth data every 30 s. The absolute change in depth over 5-min blocks was considered as a proxy for vertical activity level. Daily variations in vertical activity levels were analysed to determine the effects of time of day on whitetip reef shark behaviour. This was done for days when dive boats were absent from the area, and for days when dive boats were present, conducting shark provisioning. Vertical activity levels varied between day and night, and with the presence of boats. In natural conditions (no boats present), sharks remained at more constant depths during the day, while at night animals continuously moved up and down the water column, showing that whitetip reef sharks are nocturnally active. When boats were present, however, there were also long periods of vertical activity during the day. If resting periods during the day are important for energy budgets, then shark provisioning may affect their health. So, if this behaviour alteration occurs frequently, e.g., daily, this has the potential to have significant negative effects on the animals' metabolic rates, net energy gain and overall health, reproduction and fitness.

Fitzpatrick, Richard; Abrantes, Kátya G.; Seymour, Jamie; Barnett, Adam

2011-09-01

382

The Structure of Mediterranean Rocky Reef Ecosystems across Environmental and Human Gradients, and Conservation Implications  

PubMed Central

Historical exploitation of the Mediterranean Sea and the absence of rigorous baselines makes it difficult to evaluate the current health of the marine ecosystems and the efficacy of conservation actions at the ecosystem level. Here we establish the first current baseline and gradient of ecosystem structure of nearshore rocky reefs at the Mediterranean scale. We conducted underwater surveys in 14 marine protected areas and 18 open access sites across the Mediterranean, and across a 31-fold range of fish biomass (from 3.8 to 118 g m?2). Our data showed remarkable variation in the structure of rocky reef ecosystems. Multivariate analysis showed three alternative community states: (1) large fish biomass and reefs dominated by non-canopy algae, (2) lower fish biomass but abundant native algal canopies and suspension feeders, and (3) low fish biomass and extensive barrens, with areas covered by turf algae. Our results suggest that the healthiest shallow rocky reef ecosystems in the Mediterranean have both large fish and algal biomass. Protection level and primary production were the only variables significantly correlated to community biomass structure. Fish biomass was significantly larger in well-enforced no-take marine reserves, but there were no significant differences between multi-use marine protected areas (which allow some fishing) and open access areas at the regional scale. The gradients reported here represent a trajectory of degradation that can be used to assess the health of any similar habitat in the Mediterranean, and to evaluate the efficacy of marine protected areas.

Sala, Enric; Ballesteros, Enric; Dendrinos, Panagiotis; Di Franco, Antonio; Ferretti, Francesco; Foley, David; Fraschetti, Simonetta; Friedlander, Alan; Garrabou, Joaquim; Guclusoy, Harun; Guidetti, Paolo; Halpern, Benjamin S.; Hereu, Bernat; Karamanlidis, Alexandros A.; Kizilkaya, Zafer; Macpherson, Enrique; Mangialajo, Luisa; Mariani, Simone; Micheli, Fiorenza; Pais, Antonio; Riser, Kristin; Rosenberg, Andrew A.; Sales, Marta; Selkoe, Kimberly A.; Starr, Rick; Tomas, Fiona; Zabala, Mikel

2012-01-01

383

Biologic response to environmental stress in tropical reefs: Lessons from modern Polynesian coralgal atolls and Middle Permian sponge and Shamovella microbe reefs (Capitan Limestone USA)  

Microsoft Academic Search

Despite prejudices that comparisons of paleoecological patterns in modern and fossil reef communities are of doubtful validity, we compare the biologic response of living coralgal reefs in French Polynesia to environmental stress with an exceptionally well exposed Middle Permian sponge reef and Shamovella-microbial reef of the Capitan Limestone in New Mexico. In the western Tuamotu Archipelago, reef margins are characterized

J. A. Fagerstrom; O. Weidlich

2005-01-01

384

Extended geographic distribution of several Indo-Pacific coral reef diseases.  

PubMed

Other than coral bleaching, few coral diseases or diseases of other reef organisms have been reported from Japan. This is the first report of lesions similar to Porites ulcerative white spots (PUWS), brown band disease (BrB), pigmentation response (PR), and crustose coralline white syndrome (CCWS) for this region. To assess the health status and disease prevalence, qualitative and quantitative surveys (3 belt transects of 100 m² each on each reef) were performed in March and September 2010 on 2 reefs of the Ginowan-Ooyama reef complex off Okinawa, and 2 protected reefs off Zamani Island, in the Kerama Islands 40 km west of Okinawa. Overall, mean (±SD) disease prevalence was higher in Ginowan-Ooyama (9.7 ± 7.9%) compared to Zamami (3.6 ± 4.6%). Porites lutea was most affected by PUWS at Ooyama (23.1 ± 10.4 vs. 4.5 ± 5.2%). White syndrome (WS) mostly affected Acropora cytherea (12. 5 ± 18.0%) in Zamami and Oxipora lacera (10.2 ± 10%) in Ooyama. Growth anomalies (GA) and BrB were only observed on A. cytherea (8.3 ± 6.2%) and A. nobilis (0.8%) at Zamami. Black band disease affected Pachyseris speciosa (6.0 ± 4.6%) in Ooyama only. Pigmentation responses (PR) were common in massive Porites in both localities (2.6 ± 1.9 and 5.6 ± 2.3% respectively). Crustose coralline white syndrome (CCWS) was observed in both localities. These results significantly expand the geographic distribution of PUWS, BrB, PR and CCWS in the Indo-Pacific, indicating that the northernmost coral reefs in the western Pacific are susceptible to a larger number of coral diseases than previously thought. PMID:22436464

Weil, E; Irikawa, A; Casareto, B; Suzuki, Y

2012-03-20

385

CMPF: Class-switching minimized pathfinding in metabolic networks  

PubMed Central

Background The metabolic network is an aggregation of enzyme catalyzed reactions that converts one compound to another. Paths in a metabolic network are a sequence of enzymes that describe how a chemical compound of interest can be produced in a biological system. As the number of such paths is quite large, many methods have been developed to score paths so that the k-shortest paths represent the set of paths that are biologically meaningful or efficient. However, these approaches do not consider whether the sequence of enzymes can be manufactured in the same pathway/species/localization. As a result, a predicted sequence might consist of groups of enzymes that operate in distinct pathway/species/localization and may not truly reflect the events occurring within cell. Results We propose a path weighting method CMPF (Class-switching Minimized Pathfinder) to search for routes in a metabolic network which minimizes pathway switching. In biological terms, a pathway is a series of chemical reactions which define a specific function (e.g. glycolysis). We conjecture that routes that cross many pathways are inefficient since different pathways define different metabolic functions. In addition, native routes are also well characterized within pathways, suggesting that reasonable paths should not involve too many pathway switches. Our method can be generalized when reactions participate in a class set (e.g., pathways, species or cellular localization) so that the paths predicted have minimal class crossings. Conclusions We show that our method generates k-paths that involve the least number of class switching. In addition, we also show that native paths are recoverable and alternative paths deviates less from native paths compared to other methods. This suggests that paths ranked by our method could be a way to predict paths that are likely to occur in biological systems.

2012-01-01

386

General geology and geomorphology of the Mars Pathfinder landing site  

USGS Publications Warehouse

The Mars Pathfinder (MPF) spacecraft landed on relatively young (late Hesperian-early Amazonian; 3.1-0.7 Ga) plains in Chryse Planitia near the mouth of Ares Vallis. Images returned from the spacecraft reveal a complex landscape of ridges and troughs, large hills and crater rims, rocks and boulders of various sizes and shapes, and surficial deposits, indicating a complex, multistage geologic history of the landing site. After the deposition of one or more bedrock units, depositional and erosional fluvial processes shaped much of the present landscape. Multiple erosional events are inferred on the basis of observations of numerous channels, different orientations of many streamlined tails from their associated knobs and hills, and superposition of lineations and streamlines. Medium- and small-scale features, interpreted to be related to late-stage drainage of floodwaters, are recognized in several areas at the landing site. Streamlined knobs and hills seen in Viking orbiter images support this inference, as they seem to be complex forms, partly erosional and partly depositional, and may also indicate a series of scouring and depositional events that, in some cases, further eroded or partially buried these landforms. Although features such as these are cited as evidence for catastrophic flooding at Ares Vallis, some of these features may also be ascribed to alternative primary or secondary depositional processes, such as glacial or mass-wasting processes. Close inspection of the landing site reveals rocks that are interpreted to be volcanic in origin and others that may be conglomeratic. If such sedimentary rocks are confirmed, fluvial processes have had a greater significance on Mars than previously thought. For the last several hundred million to few billion years, eolian processes have been dominant. Dunes and dune-like features, ventifacts, and deflation and exhumation features around several rocks probably are the most recent landforms. The relatively pristine nature of the overall landscape at the MPF site suggests weathering and erosion processes on Mars are exceptionally slow.

Ward, A. W.; Gaddis, L. R.; Kirk, R. L.; Soderblom, L. A.; Tanaka, K. L.; Golombek, M. P.; Parker, T. J.; Greeley, Ronald; Kuzmin, R. O.

1999-01-01

387

Mineralogy, composition, and alteration of Mars Pathfinder rocks and soils: Evidence from multispectral, elemental, and magnetic data on terrestrial analogue, SNC meteorite, and Pathfinder samples  

NASA Astrophysics Data System (ADS)

Major element, multispectral, and magnetic properties data were obtained at Ares Vallis during the Mars Pathfinder mission. To understand the compositional, mineralogical, and process implications of these data, we obtained major element, mineralogical, and magnetic data for well-crystalline and nanophase ferric minerals, terrestrial analogue samples with known geologic context, and SNC meteorites. Analogue samples include unaltered, palagonitic, and sulfatetic tephra from Mauna Kea Volcano (hydrolytic and acid-sulfate alteration), steam vent material from Kilauea Volcano (hydrolytic alteration), and impactites from Meteor Crater (relithification). Salient results for Mars Pathfinder include: (1) Band depths BD530b and BD600 and the reflectivity ratio R800/R750 are consistent with the dominant ferric mineral being nanophase ferric oxide associated with an unknown amount of H2O and occurring in composite particles along with subordinate amounts of other ferric minerals. Hematite and hematite plus nanophase goethite are most consistent with the data, but maghemite, akaganéite, schwertmannite, and nanophase lepidocrocite are also possible interpretations. Ferric oxides that are consistently not favored by the data as sole alteration products are jarosites and well-crystalline goethite and lepidocrocite. (2) The strength of the ferric adsorption edge (R750/R445) implies the Fe3+/Fe2+ values for Pathfinder rock and soil are within the ranges 0.7-3 and 3-20, respectively. (3) Ferrous silicates are indicated for subsets of Pathfinder rocks and soils. One subset has a band minimum near 930 nm that can attributed to low-Ca pyroxene. Alternatively, the band could be a second manifestation of certain ferric oxides, including nanophase goethite, maghemite, akaganéite, and schwertmannite. Another subset has a negative spectral slope from ~800 to 1005 nm which could result from the high-energy wing of a high-Ca pyroxene and/or olivine band, a mixture of bright and dark materials, and, for rocks, thin coatings of bright dust on dark rocks. (4) Chemical data on Pathfinder rocks and soils are consistent with two-component mixtures between an ``andesitic'' rock with low MgO and SO3 concentrations (soil-free rock) and a global, basaltic soil with high MgO and SO3 concentrations (rock-free soil). Pathfinder rock-free soil can be modeled as a chemical mixture of SNC meteorites and the Pathfinder soil-free rock. (5) Pathfinder soil cannot be obtained by chemical alteration of Pathfinder rocks by any of the hydrolytic and acid-sulfate alteration processes we studied. Presumably, global mixing has obscured and possibly erased the elemental signatures of chemical alteration. (6) The strongly magnetic phase in palagonitic and sulfatetic tephra is titanomagnetite and possibly its oxidation product titanomaghemite (Fe-Ti spinels). The saturation magnetization of the tephra samples (0.5-2.0 Am2/kg) is at or below the low end of the range inferred for Martian dust (4+/-2Am2/kg), implying that lithogenic Fe-Ti spinels are a possible candidate for the Martian strongly magnetic phase. (7) The predominantly palagonitic spectral signature and magnetic nature of Martian soil and dust are consistent with glassy precursors with imbedded Fe-Ti spinel particles. Comparison with lunar glass production rates suggests that production of sufficient quantities of glassy materials on Mars by volcanic and impact processes is sufficient to account for these observations.

Morris, Richard V.; Shelfer, Tad D.; Scheinost, Andreas C.; Hinman, Nancy W.; Furniss, George; Mertzman, Stanley A.; Bishop, Janice L.; Ming, Douglas W.; Allen, Carlton C.; Britt, Daniel T.

2000-01-01

388

Mineralogy, composition, and alteration of Mars Pathfinder rocks and soils: Evidence from multispectral, elemental, and magnetic data on terrestrial analogue, SNC meteorite, and Pathfinder samples  

NASA Astrophysics Data System (ADS)

Major element, multispectral, and magnetic properties data were obtained at Ares Vallis during the Mars Pathfinder mission. To understand the compositional, mineralogical, and process implications of these data, we obtained major element, mineralogical, and magnetic data for well-crystalline and nanophase ferric minerals, terrestrial analogue samples with known geologic context, and SNC meteorites. Analogue samples include unaltered, palagonitic, and sulfatetic tephra from Mauna Kea Volcano (hydrolytic and acid-sulfate alteration), steam vent material from Kilauea Volcano (hydrolytic alteration), and impactites from Meteor Crater (relithification). Salient results for Mars Pathfinder include: (1) Band depths BD530b and BD600 and the reflectivity ratio R800/R750 are consistent with the dominant ferric mineral being nanophase ferric oxide associated with an unknown amount of H2O and occurring in composite particles along with subordinate amounts of other ferric minerals. Hematite and hematite plus nanophase goethite are most consistent with the data, but maghemite, akaganéite, schwertmannite, and nanophase lepidocrocite are also possible interpretations. Ferric oxides that are consistently not favored by the data as sole alteration products are jarosites and well-crystalline goethite and lepidocrocite. (2) The strength of the ferric adsorption edge (R750/R445) implies the Fe3+/Fe2+ values for Pathfinder rock and soil are within the ranges 0.7-3 and 3-20, respectively. (3) Ferrous silicates are indicated for subsets of Pathfinder rocks and soils. One subset has a band minimum near 930 nm that can attributed to low-Ca pyroxene. Alternatively, the band could be a second manifestation of certain ferric oxides, including nanophase goethite, maghemite, akaganéite, and schwertmannite. Another subset has a negative spectral slope from ~800 to 1005 nm which could result from the high-energy wing of a high-Ca pyroxene and/or olivine band, a mixture of bright and dark materials, and, for rocks, thin coatings of bright dust on dark rocks. (4) Chemical data on Pathfinder rocks and soils are consistent with two-component mixtures between an ``andesitic'' rock with low MgO and SO3 concentrations (soil-free rock) and a global, basaltic soil with high MgO and SO3 concentrations (rock-free soil). Pathfinder rock-free soil can be modeled as a chemical mixture of SNC meteorites and the Pathfinder soil-free rock. (5) Pathfinder soil cannot be obtained by chemical alteration of Pathfinder rocks by any of the hydrolytic and acid-sulfate alteration processes we studied. Presumably, global mixing has obscured and possibly erased the elemental signatures of chemical alteration. (6) The strongly magnetic phase in palagonitic and sulfatetic tephra is titanomagnetite and possibly its oxidation product titanomaghemite (Fe-Ti spinels). The saturation magnetization of the tephra samples (0.5-2.0 Am2/kg) is at or below the low end of the range inferred for Martian dust (4+/-2?Am2/kg), implying that lithogenic Fe-Ti spinels are a possible candidate for the Martian strongly magnetic phase. (7) The predominantly palagonitic spectral signature and magnetic nature of Martian soil and dust are consistent with glassy precursors with imbedded Fe-Ti spinel particles. Comparison with lunar glass production rates suggests that production of sufficient quantities of glassy materials on Mars by volcanic and impact processes is sufficient to account for these observations.

Morris, Richard V.; Golden, D. C.; Bell, James F.; Shelfer, Tad D.; Scheinost, Andreas C.; Hinman, Nancy W.; Furniss, George; Mertzman, Stanley A.; Bishop, Janice L.; Ming, Douglas W.; Allen, Carlton C.; Britt, Daniel T.

2000-01-01

389

Coral reef formation theory may apply to oil, gas exploration  

SciTech Connect

This paper reports a coral reef formation theory that has implications for hydrocarbon exploration. The theory states that many coral reefs and carbonate buildups from at and are dependent upon nutrient rich fluids seeping through the seabed.

Not Available

1990-12-10

390

Checklist of fishes from madagascar reef, campeche bank, méxico.  

PubMed

This study presents the first list of fish species from Madagascar Reef, Campeche Bank, Gulf of México. Field surveys and literature review identified 54 species belonging to 8 orders, 30 families and 43 genera, comprising both conspicuous and cryptic fishes. Species richness was lower at this reef site compared to reefs in the Mexican Caribbean, Veracruz or Tuxpan, but was similar to other reefs in the same region. Species composition was a mixture of species present in all the reef systems of the Mexican Atlantic. Hypoplectrusecosur was recorded here for the first time in the Gulf of Mexico, Mycteropercamicrolepis, Equetuslanceolatus and Chaetodipterusfaber were new records for the reefs of the Campeche Bank, Elacatinusxanthiprora was recorded for the second time in Mexico and expanded its known distribution westwards from Alacranes Reef and Sanopusreticulatus, endemic of the Yucatan state, was recorded here for the first time on a reef. PMID:24891834

Zarco Perello, Salvador; Moreno Mendoza, Rigoberto; Simões, Nuno

2014-01-01

391

Reef-sourced slope deposits, Holocene, Bahamas  

SciTech Connect

Observations and sampling to 350 m from a two-person submersible off Chub Cay, Berry Island, Bahamas, support the idea that the Holocene deep reef is a principal source of talus, now cemented, that foots the windward margins of Great Bahama Bank. At the Chub Cay dive site, a wall extends from 30 to 170 m subsea; below is a low-relief fore reef slope, ca. 50/sup 0/, of limestone veneered with sediment. The upper wall from 30 to 80 m, the deep reef, has a luxuriant growth of corals and a profusion of the calcareous alga halimeda spp. Below 50 m, living coral decreases, and from 80 to 170 m the wall is highly irregular with discontinuous ledges and blind-end caves. At depths from 150 to 170 m, the wall gives way to the fore reef slope whose relative smooth surface dips at 50/sup 0/ to 60/sup 0/ and extends to 350 m. The fore reef is limestone, but its topography resembles that of alluvial fans; rounded ridges rise a few meters above the intervening valleys that are tens of meters wide. The limestone surface has a discontinuous veneer of fine sediment and algal plates, and locally loose cobble and boulder-sized blocks of limestone. A sample of the limestone slope is of well-cemented coral clasts and skeletal sediment. They infer that the deep reef grows outward so rapidly that it caves periodically. The resulting debris bypasses the wall, but some is perched on the steep fore reef slope below where it is soon incorporated into the slope by submarine cementation.

Ginsburg, R.N.; Eberli, G.P.; Harris, P.M.; Slater, R.; Swart, P.K.

1987-05-01

392

Spinocerebellar ataxia type 13 mutation that is associated with disease onset in infancy disrupts axonal pathfinding during neuronal development  

PubMed Central

SUMMARY Spinocerebellar ataxia type 13 (SCA13) is an autosomal dominant disease caused by mutations in the Kv3.3 voltage-gated potassium (K+) channel. SCA13 exists in two forms: infant onset is characterized by severe cerebellar atrophy, persistent motor deficits and intellectual disability, whereas adult onset is characterized by progressive ataxia and progressive cerebellar degeneration. To test the hypothesis that infant- and adult-onset mutations have differential effects on neuronal development that contribute to the age at which SCA13 emerges, we expressed wild-type Kv3.3 or infant- or adult-onset mutant proteins in motor neurons in the zebrafish spinal cord. We characterized the development of CaP (caudal primary) motor neurons at ?36 and ?48 hours post-fertilization using confocal microscopy and 3D digital reconstruction. Exogenous expression of wild-type Kv3.3 had no significant effect on CaP development. In contrast, CaP neurons expressing the infant-onset mutation made frequent pathfinding errors, sending long, abnormal axon collaterals into muscle territories that are normally innervated exclusively by RoP (rostral primary) or MiP (middle primary) motor neurons. This phenotype might be directly relevant to infant-onset SCA13 because interaction with inappropriate synaptic partners might trigger cell death during brain development. Importantly, pathfinding errors were not detected in CaP neurons expressing the adult-onset mutation. However, the adult-onset mutation tended to increase the complexity of the distal axonal arbor. From these results, we speculate that infant-onset SCA13 is associated with marked changes in the development of Kv3.3-expressing cerebellar neurons, reducing their health and viability early in life and resulting in the withered cerebellum seen in affected children.

Issa, Fadi A.; Mock, Allan F.; Sagasti, Alvaro; Papazian, Diane M.

2012-01-01

393

An automatic identification and monitoring system for coral reef fish  

NASA Astrophysics Data System (ADS)

To help gauge the health of coral reef ecosystems, we developed a prototype of an underwater camera module to automatically census reef fish populations. Recognition challenges include pose and lighting variations, complicated backgrounds, within-species color variations and within-family similarities among species. An open frame holds two cameras, LED lights, and two `background' panels in an L-shaped configuration. High-resolution cameras send sequences of 300 synchronized image pairs at 10 fps to an on-shore PC. Approximately 200 sequences containing fish were recorded at the New York Aquarium's Glover's Reef exhibit. These contained eight `common' species with 85-672 images, and eight `rare' species with 5-27 images that were grouped into an `unknown/rare' category for classification. Image pre-processing included background modeling and subtraction, and tracking of fish across frames for depth estimation, pose correction, scaling, and disambiguation of overlapping fish. Shape features were obtained from PCA analysis of perimeter points, color features from opponent color histograms, and `banding' features from DCT of vertical projections. Images were classified to species using feedforward neural networks arranged in a three-level hierarchy in which errors remaining after each level are targeted by networks in the level below. Networks were trained and tested on independent image sets. Overall accuracy of species-specific identifications typically exceeded 96% across multiple training runs. A seaworthy version of our system will allow for population censuses with high temporal resolution, and therefore improved statistical power to detect trends. A network of such devices could provide an `early warning system' for coral ecosystem collapse.

Wilder, Joseph; Tonde, Chetan; Sundar, Ganesh; Huang, Ning; Barinov, Lev; Baxi, Jigesh; Bibby, James; Rapport, Andrew; Pavoni, Edward; Tsang, Serena; Garcia, Eri; Mateo, Felix; Lubansky, Tanya M.; Russell, Gareth J.

2012-10-01

394

CORAL DISEASE & HEALTH CONSORTIUM; PARTNERS FOR PRESERVATION  

EPA Science Inventory

Presented at EMAP Symposium 2001: Coastal Monitoring Through Partnerships, 24-27 April 2001, Pensacola Beach, FL. The Coral Disease and Health Consortium (CDHC) was one recommendation to the U.S. Coral Reef Task Force (CRTF), to conserve the coral reef ecosystems of the U...

395

Mars Pathfinder Landing Site Workshop II: Characteristics of the Ares Vallis Region and Field Trips in the Channeled Scabland, Washington  

Microsoft Academic Search

Mars Pathfinder will place a single lander on the surface of Mars on July 4, 1997, following a December 1996 launch. As a result of the very successful first Mars Pathfinder Landing Site Workshop, the project has selected the Ares Vallis outflow channel in Chryse Planitia as the landing site. This location is where a large catastrophic outflow channel debouches

M. P. Golombek; K. S. Edgett; J. W. Rice Jr.

1995-01-01

396

“Faster, better, cheaper” technologies used in the attitude and information management subsystem for the Mars Pathfinder mission  

Microsoft Academic Search

The “Faster, Better, Cheaper” thrust at NASA\\/JPL has pushed new technologies into spacecraft designed for interplanetary missions. This is especially true for “Discovery” class missions such as Mars Pathfinder. This mission is set to send a lander and enclosed microrover to the surface of Mars for a “low cost”. The Pathfinder flight system must be built for $150M (FY92 dollars)

D. F. Woerner; David H. Lehman

1995-01-01

397

Measurement of the settling rate of atmospheric dust on Mars by the MAE instrument on Mars Pathfinder  

Microsoft Academic Search

The Materials Adherence Experiment (MAE) on Pathfinder was designed to measure the rate of dust settling from the Martian atmosphere onto the solar array of the Mars Pathfinder Sojourner Rover. The MAE measurements indicate steady dust accumulation at a rate of about 0.28% per day. This value is consistent with the performance of the lander solar arrays, which decreased in

Geoffrey A. Landis; Phillip P. Jenkins

2000-01-01

398

Digital photogrammetric analysis of the IMP camera images: Mapping the Mars Pathfinder landing site in three dimensions  

Microsoft Academic Search

This paper describes our photogrammetric analysis of the Imager for Mars Pathfinder data, part of a broader program of mapping the Mars Pathfinder landing site in support of geoscience investigations. This analysis, carried out primarily with a commercial digital photogrammetric system, supported by our in-house Integrated Software for Imagers and Spectrometers (ISIS), consists of three steps: (1) geometric control: simultaneous

R. L. Kirk; E. Howington-Kraus; T. Hare; E. Dorrer; D. Cook; K. Becker; K. Thompson; B. Redding; J. Blue; D. Galuszka; E. M. Lee; L. R. Gaddis; J. R. Johnson; L. A. Soderblom; A. W. Ward; P. H. Smith; D. T. Britt

1999-01-01

399

The National Oceanic and Atmospheric Administration's Coral Reef Conservation Program  

NSDL National Science Digital Library

This NOAA program supports effective management and sound science to preserve, sustain and restore valuable coral reef ecosystems. Students can read about the U.S. Coral Reef Task Force, learn more about local and national coral reef action strategies, and find links to more information on coral reefs. The site also offers a search for publications and data and a general search of the site.

400

Optical spectra and pigmentation of Caribbean reef corals and macroalgae  

Microsoft Academic Search

Coastal reef degradation and widespread bleaching of corals, i.e. loss of pigments and\\/or symbiotic zooxanthellae, is increasing\\u000a globally. Remote sensing from boats, aircraft or satellites has great potential for assessing the extent of reef change, but\\u000a will require ground-verified spectral algorithims characteristic of healthy and degraded reef populations. We collected seven\\u000a species of Caribbean reef corals and also representative macroalgae

M. R. Myers; J. T. Hardy; C. H. Mazel; P. Dustan

1999-01-01

401

Pathfinder technologies for bold new missions. [U.S. research and development program for space exploration  

NASA Technical Reports Server (NTRS)

Project Pathfinder is a proposed U.S. Space Research and Technology program intended to enable bold new missions of space exploration. Pathfinder continues the advancement of technological capabilities and extends the foundation established under the Civil Space Technology Initiative, CSTI. By filling critical technological gaps, CSTI enhances access to Earth orbit and supports effective operations and science missions therein. Pathfinder, with a longer-term horizon, looks to a future that builds on Shuttle and Space Station and addresses technologies that support a range of exploration missions including: a return to the Moon to build an outpost; piloted missions to Mars; and continued scientific exploration of Earth and the other planets. The program's objective is to develop, within reasonable time frames, those emerging and innovative technologies that will make possible both new and enhanced missions and system concepts.

Sadin, Stanley R.; Rosen, Robert

1987-01-01

402

Preliminary Findings of the Photovoltaic Cell Calibration Experiment on Pathfinder Flight 95-3  

NASA Technical Reports Server (NTRS)

The objective of the photovoltaic (PV) cell calibration experiment for Pathfinder was to develop an experiment compatible with an ultralight UAV to predict the performance of PV cells at AM0, the solar spectrum in space, using the Langley plot technique. The Langley plot is a valuable technique for this purpose and requires accurate measurements of air mass (pressure), cell temperature, solar irradiance, and current-voltage(IV) characteristics with the cells directed normal to the direct ray of the sun. Pathfinder's mission objective (95-3) of 65,000 ft. maximum altitude, is ideal for performing the Langley plot measurements. Miniaturization of electronic data acquisition equipment enabled the design and construction of an accurate and light weight measurement system that meets Pathfinder's low payload weight requirements.

Vargas-Aburto, Carlos

1997-01-01

403

Boundary Reefs: Glass Sponge (Porifera Hexactinellidae) Reefs on the International Border Between Canada and the United States.  

National Technical Information Service (NTIS)

Hexactinellid sponge reefs have been discovered in shallow-water areas in Portland Canal on the international boundary between Southeast Alaska and British Columbia. The reefs were first observed on multibeam imagery data collected in 2008 and were examin...

D. J. Csepp J. V. Barrie K. W. Conway R. P. Stone

2014-01-01

404

Exploring Drowned Reefs on Gardner Pinnacles  

NASA Astrophysics Data System (ADS)

Gardner Pinnacles (GP), located in the Northwest Hawaiian Islands within Papah?naumoku?kea Marine National Monument, is one of the largest volcanic structures in the entire Hawaiian-Emperor chain. In Oct. 2011, the R/V Ka'imikai-o-Kanaloa mapped and the Pisces IV submersible explored the GP during 7 dives, mainly on drowned reef terraces. New multibeam bathymetric data from the cruise, combined with pre-existing multibeam data mostly collected during transits across the structure, show at least 4 separate volcanoes partially surrounded by several Miocene to Pleistocene drowned coral reefs with extensive lagoons, with the largest volcano surmounted by an active carbonate platform. Large landslides modify the flanks, and the eastern flank is incised by submarine canyons. Seven submersible dives explored and sampled mainly the drowned reef structures. The largest reef complex is on the NW flank above the main break-in-slope, and is a barrier reef surrounding extensive lagoon deposits with complex channel structures. Similar wide lagoons with deep channels parallel to the outer reef terraces are present elsewhere on GP, but unusual elsewhere in the Hawaiian Islands. Seven corals, coralline algae, and echinoid spines from dive P4-266 on that NW edge of GP from 1268-1637 m depth yield a tight age cluster based on Sr-isotopes calibrated to seawater that range from 15.51 to 15.98 Ma, and average 15.76 Ma. Five ages of echinoid spines, mollusk shells, and large foraminfers from dive P4-255 on the SW edge of GP from 1538-1558 m depth range from 14.88 to 15.10 Ma, and average 14.98 Ma. Three ages of corals and coralline algae from dive P4-253 on the SE edge of GP at 1955 m depth range from 12.35 and 12.7 Ma, and average 12.57 Ma. The ages of these reefs indicate when volcanic activity waned and reef deposits could accumulate without constant burial by lava flows; the nearly 3.2 Ma range in reef ages from the flanks of GP suggest that volcanic activity at GP spanned a similar time period. The NW barrier reef is a 310-m-tall ridge surmounted by 140-m pinnacles, consistent with rapid upward growth during the Middle Miocene Climatic Optimum. With two exceptions, all carbonate samples collected from <910 m and a few from deeper terraces, yielded Pleistocene or younger ages. The Pleistocene aged samples on such deep reefs suggest extensive downslope transport of reef debris. Lava samples collected during the dives include tholeiitic shield-stage lavas and several rounded postshield-stage hawaiite cobbles in volcanic/carbonate beach sandstone. Published K-Ar age of volcanic rocks from GP of 12.3±1.0 Ma (Garcia et al., 1987) is inconsistent with the older ages of the overlying reefs. New Ar-Ar age data of samples from the dive program will be presented.

Clague, D. A.; Paduan, J. B.; Braga, J. C.; Humphrey, C.; Hinestrosa, G.; Fullagar, P. D.

2012-12-01

405

Reef development at the Frasnian\\/Famennian mass extinction boundary  

Microsoft Academic Search

A newly compiled global reef database indicates that the 5–6 Myr long Frasnian (Late Devonian) metazoan reef episode had relatively low diversity compared to Middle Devonian highs (with over 200 genera of calcitic rugose and tabulate corals). Following an initial early rise after Late Givetian coral and stromatoporoid extinctions, reefs expanded for the last time during mid-Frasnian sealevel highstands, but

Paul Copper

2002-01-01

406

Where in the world are Winslow Reef and Amelia Earhart?  

Microsoft Academic Search

Uncharted or doubtful positions of shoals and reefs have played a large role in the history of maritime navigation and oceanography. Two of these shoals, Winslow Reef and Reef and Sand Bank in the central equatorial Pacific, were the subjects of a fruitless 2-day aerial search in 1937 for Amelia Earhart by planes from the battleship USS Colorado.Sightings before and

R. S. Jacobson

1994-01-01

407

Coral reef recovery dynamics in a changing world  

Microsoft Academic Search

Coral reef ecosystems are degrading through multiple disturbances that are becoming more frequent and severe. The complexities of this degradation have been studied in detail, but little work has assessed characteristics that allow reefs to bounce back and recover between pulse disturbance events. We quantitatively review recovery rates of coral cover from pulse disturbance events among 48 different reef locations,

N. A. J. Graham; K. L. Nash; J. T. Kool

2011-01-01

408

Spectral unmixing of coral reef benthos under ideal conditions  

Microsoft Academic Search

Hyperspectral remote sensing has shown promise for detailed discrimination of coral reef substratum types, but, by necessity, it samples at pixel scales larger than reef substratum patch sizes. Spectral unmixing techniques have been successful in resolving subpixel areal cover in terrestrial environments. However, the application of spectral unmixing on coral reefs is fundamentally challenging, due not only to the water

J. D. Hedley; P. J. Mumby; K. E. Joyce; S. R. Phinn

2004-01-01

409

The Isla de Lobos and Associated Reefs, Veracruz, Mexico.  

National Technical Information Service (NTIS)

The reef which surrounds Isla de Lobos is one of three closely associated reefs on the eastern coast of Mexico, approximately 70 miles southeast of Tampico, Tamaulipas, and is the northernmost reef with a sand cay on the western margin of the Gulf of Mexi...

J. K. Rigby W. G. McIntire

1966-01-01

410

Phase shifts in coral reef communities and their ecological significance  

Microsoft Academic Search

Many coral reefs around the world have degraded to a degree that their present intrinsic value and utility are greatly reduced: (mass coral mortality followed by algal invasions; local depletions of reef fisheries; deficit of reef accretion compared to physical and biological erosion). Though we can sometimes identify proximal causes (outbreaks of coral predators and eroders; over-fishing; habitat destruction), we

T. J. Done; Townsville MC

1992-01-01

411

EFFECTS OF DRILLING FLUIDS ON REEF CORALS: A REVIEW  

EPA Science Inventory

This chapter reviews research on the effects of drilling mud on coral reef communities, concentrating on the major reef fauna: the reef-building or hermatypic corals. Drilling mud is an effluent introduced to the marine environment in large quantities during the typical offshore ...

412

Coral Reef Education and Australian High School Students  

ERIC Educational Resources Information Center

Educational programs that focus on humans and their relationship to coral reefs are becoming necessary, as reef structures along the Queensland coast come under mounting ecological pressure. This paper reports on a PhD research project which investigated marine education and learning with high school students in coral reef environments along the…

Stepath, Carl M.

2004-01-01

413

Coral Reefs: A Gallery Program, Grades 7-12.  

ERIC Educational Resources Information Center

Gallery classes at the National Aquarium in Baltimore give the opportunity to study specific aquarium exhibits which demonstrate entire natural habitats. The coral reef gallery class features the gigantic western Atlantic coral reef (325,000 gallons) with over 1,000 fish. The exhibit simulates a typical Caribbean coral reef and nearby sandy…

National Aquarium in Baltimore, MD. Dept. of Education.

414

Apparatus for simultaneously disreefing a centrally reefed clustered parachute system  

Microsoft Academic Search

A single multi-line cutter is connected to each of a cluster of parachutes by a separate short tether line that holds the parachutes, initially reefed by closed loop reefing lines, close to one another. The closed loop reefing lines and tether lines, one from each parachute, are disposed within the cutter to be simultaneously cut by its actuation when a

Johnson

1988-01-01

415

Apparatus for simultaneously disreefing a centrally reefed clustered parachute system  

Microsoft Academic Search

A single multi-line cutter is connected to each of a cluster of parachutes by a separate short tether line that holds the parachutes, initially reefed by closed loop reefing lines, close to one another. The closed loop reefing lines and tether lines, one from each parachute, are disposed within the cutter to be simultaneously cut by its actuation when a

Johnson

1986-01-01

416

Biology and geology of eastern Pacific coral reefs  

Microsoft Academic Search

The tropical eastern Pacific region has historically been characterized as devoid of coral reefs. The physical conditions of the region are apparently not conducive to reef growth: low temperatures, low salinity, and high nutrient loads. But recent work has demonstrated persistent coral growth in some locations at relatively high accretion rates, dating at least 5600 y before present. Coral reefs

J. Cortés

1997-01-01

417

Detecting ecological change on coral reefs  

NASA Astrophysics Data System (ADS)

Remote sensing offers the potential to observe the response of coral reef ecosystems to environmental perturbations on a geographical scale not previously accessible. However, coral reef environments are optically, spatially, and temporally complex habitats which all present significant challenges for extracting meaningful information. Virtually every member of the reef community possesses some degree of photosynthetic capability. The community thus generates a matrix of fine scale features with bio-optical signatures that blend as the scale of observation increases. Furthermore, to have any validity, the remotely sensed signal must be "calibrated" to the bio-optics of the reef, a difficult and resource intensive process due to a convergence of photosynthetic light harvesting by green, red, and brown algal pigment systems. To make matters more complex, reefs are overlain by a seawater skin with its own set of hydrological optical challenges. Rather than concentrating on classification, my research has attempted to track change by following the variation in geo-referenced pixel brightness over time with a technique termed temporal texture. Environmental periodicities impart a phenology to the variation in brightness and departures from the norm are easily detected as statistical outliers. This opens the door to using current orbiting technology to efficiently examine large areas of sea for change. If hot spots are detected, higher resolution sensors and field studies can be focused as resources permit. While this technique does not identify the type of change, it is sensitive, simple to compute, easy to automate and grounded in ecological niche theory

Dustan, P.

2011-12-01

418

Surface alkaline phosphatase activities of macroalgae on coral reefs of the central Great Barrier Reef, Australia  

NASA Astrophysics Data System (ADS)

Inshore reefs of the Great Barrier Reef (GBR) are subject to episodic nutrient supply, mainly by flood events, whereas midshelf reefs have a more consistent low nutrient availability. Alkaline phosphatase activity (APA) enables macroalgae to increase their phosphorus (P) supply by using organic P. APA was high (~4.0 to 15.5 µmol PO4 3- g DW-1 h-1) in species colonising predominantly inshore reefs and low (<2 µmol PO4 3- g DW-1 h-1) in species with a cross-shelf distribution. However, APA values of GBR algae in this study were much lower than data reported from other coral reef systems. In experiments with two Sargassum species tissue P levels were correlated negatively, and N:P ratios were positively correlated with APA. High APA can compensate for a relative P-limitation of macroalgae in coral reef systems that are subject to significant N-inputs, such as the GBR inshore reefs. APA and other mechanisms to acquire a range of nutrient species allow inshore species to thrive in habitats with episodic nutrient supply. These species also are likely to benefit from an increased nutrient supply caused by human activity, which currently is a global problem.

Schaffelke, B.

2001-05-01

419

Observations by the Mars 1994 orbiter and possible correlations with Mars Pathfinder  

NASA Technical Reports Server (NTRS)

The Mars '94 spacecraft will still be operational when Mars Pathfinder begins its observations. While it will probably not be possible to detect the lander directly, the terrain, including the landing error ellipse, can be covered in high resolution (10 m) in various color bands. The stereo capability of the high resolution camera will provide a three-dimensional terrain map. The landing site of Pathfinder could possibly be chosen so that correlated observations of IMP and the remote sensing instruments onboard Mars '94 may be possible. We will discuss this scenario based on the presently adopted Mars '94 orbit and resulting enhancements stemming from correlations of data obtained by both spacecraft.

Keller, H. Uwe

1994-01-01

420

Mineralogic and compositional properties of Martian soil and dust: results from Mars Pathfinder  

USGS Publications Warehouse

Mars Pathfinder obtained multispectral, elemental, magnetic, and physical measurements of soil and dust at the Sagan Memorial Station during the course of its 83 sol mission. We describe initial results from these measurements, concentrating on multispectral and elemental data, and use these data, along with previous Viking, SNC meteorite, and telescopic results, to help constrain the origin and evolution of Martian soil and dust. We find that soils and dust can be divided into at least eight distinct spectral units, based on parameterization of Imager for Mars Pathfinder (IMP) 400 to 1000 nm multispectral images. The most distinctive spectral parameters for soils and dust are the reflectivity in the red, the red/blue reflectivity ratio, the near-IR spectral slope, and the strength of the 800 to 1000 nm absorption feature. Most of the Pathfinder spectra are consistent with the presence of poorly crystalline or nanophase ferric oxide(s), sometimes mixed with small but varying degrees of well-crystalline ferric and ferrous phases. Darker soil units appear to be coarser-grained, compacted, and/or mixed with a larger amount of dark ferrous materials relative to bright soils. Nanophase goethite, akaganeite, schwertmannite, and maghemite are leading candidates for the origin of the absorption centered near 900 nm in IMP spectra. The ferrous component in the soil cannot be well-constrained based on IMP data. Alpha proton X-ray spectrometer (APXS) measurements of six soil units show little variability within the landing site and show remarkable overall similarity to the average Viking-derived soil elemental composition. Differences exist between Viking and Pathfinder soils, however, including significantly higher S and Cl abundances and lower Si abundances in Viking soils and the lack of a correlation between Ti and Fe in Pathfinder soils. No significant linear correlations were observed between IMP spectral properties and APXS elemental chemistry. Attempts at constraining the mineralogy of soils and dust using normative calculations involving mixtures of smectites and silicate and oxide minerals did not yield physically acceptable solutions. We attempted to use the Pathfinder results to constrain a number of putative soil and dust formation scenarios, including palagonitization and acid-fog weathering. While the Pathfinder soils cannot be chemically linked to the Pathfinder rocks by palagonitization, this study and McSween et al. [1999] suggest that palagonitic alteration of a Martian basaltic rock, plus mixture with a minor component of locally derived andesitic rock fragments, could be consistent with the observed soil APXS and IMP properties.

Bell, J. F., III; McSween, H. Y., Jr.; Crisp, J. A.; Morris, R. V.; Murchie, S. L.; Bridges, N. T.; Johnson, J. R.; Britt, D. T.; Golombek, M. P.; Moore, H. J.; Ghosh, A.; Bishop, J. L.; Anderson, R. C.; Brückner, J.; Economou, T.; Greenwood, J. P.; Gunnlaugsson, H. P.; Hargraves, R. M.; Hviid, S.; Knudsen, J. M.; Madsen, M. B.; Reid, R.; Rieder, R.; Soderblom, L.

2000-01-01

421

76 FR 68711 - Amendments to the Reef Fish, Spiny Lobster, Queen Conch and Coral and Reef Associated Plants and...  

Federal Register 2010, 2011, 2012, 2013

...Fish, Spiny Lobster, Queen Conch and Coral and Reef Associated Plants and Invertebrates...Islands, and Amendment 3 to the FMP for Corals and Reef Associated Plants and Invertebrates...procedures for the spiny lobster and Caribbean corals and reef associated plants and...

2011-11-07

422

76 FR 82413 - Amendments to the Reef Fish, Spiny Lobster, Queen Conch and Coral and Reef Associated Plants and...  

Federal Register 2010, 2011, 2012, 2013

...Fish, Spiny Lobster, Queen Conch and Coral and Reef Associated Plants and Invertebrates...Fish, Spiny Lobster, Queen Conch and Coral and Reef Associated Plants and Invertebrates...FMP), and Amendment 3 to the FMP for Corals and Reef Associated Plants and...

2011-12-30

423

Reef Water CO2 System and Carbon Production of Coral Reefs: Topographic Control of System-Level Performance  

Microsoft Academic Search

The variations of seawater CO2 system and organic and inorganic carbon production of coral reefs were investigated with respect to topographic types and oceanographic settings. Because of dominant carbonate production in coral reef ecosystems, most coral reefs are likely to act as a net or at least a potential CO2 source to the atmosphere. The comparison of the seawater CO2

Atsushi SUZUKI; Hodaka KAWAHATA

2004-01-01

424

Alkaline phosphatase activity of coral reef benthos  

NASA Astrophysics Data System (ADS)

Alkaline Phosphatase (AP-ase) activity was measured for a variety of benthic algae and a community of reef organisms. Algae with epiphytic bacteria showed a higher AP-ase activity than algae without bacteria (11.6 ?mol P g-1 h-1 vs. 1.9?mol P g-1h-1). AP-ase activity associated with the benthos was estimated to be in the range of 10 100 mmol P m-2d-1, at least 1000 Cold greater than reported activity in the water column. Enzyme activity of reef benthos at saturated organic phosphate (P) substrate concentrations was sufficiently high that P uptake from organic substrates could be as fast as inorganic P uptake. Organic P compounds may be important in P recycling, but there is no evidence that organic P represents a significant new source of P to coral reefs.

Atkinson, M. J.

1987-10-01

425

Ecology of artificial reefs in the subtropics.  

PubMed

The application of artificial reefs (ARs) has a long history, and there is a wealth of information related to the design and performance of ARs in coastal and ocean waters worldwide. However, relatively fewer studies in the literature are focused on the response of benthic communities within the reef areas than those on fish attraction and fish production and on the settlement and colonization of epibiota on the AR structures, especially in the subtropics where seasonal differences and environmental conditions can be large. Recent advances in the understanding of the ecology of ARs in the subtropics are highlighted, with a focus on fish attraction versus fish production, development of epibiota on AR systems and responses of in situ benthic communities in the reef areas. Data are also presented on studies of trophic relationships in subtropical AR systems, and further research areas using analyses of biological traits, stable isotope signatures and fatty acid profiles in investigating the ecology of ARs are proposed. PMID:24981732

Shin, Paul K S; Cheung, Siu Gin; Tsang, Tsui Yun; Wai, Ho Yin

2014-01-01

426

Geochemical consequences of increased atmospheric carbon dioxide on coral reefs  

USGS Publications Warehouse

A coral reef represents the net accumulation of calcium carbonate (CaCO3) produced by corals and other calcifying organisms. If calcification declines, then reef-building capacity also declines. Coral reef calcification depends on the saturation state of the carbonate mineral aragonite of surface waters. By the middle of the next century, an increased concentration of carbon dioxide will decrease the aragonite saturation state in the tropics by 30 percent and biogenic aragonite precipitation by 14 to 30 percent. Coral reefs are particularly threatened, because reef-building organisms secrete metastable forms of CaCO3, but the biogeochemical consequences on other calcifying marine ecosystems may be equally severe.

Kleypas, J. A.; Buddemeier, R. W.; Archer, D.; Gattuso, J. -P.; Langdon, C.; Opdyke, B. N.

1999-01-01

427

Bill Would Allow Platforms as Artificial Reefs  

NASA Astrophysics Data System (ADS)

A 17 September U.S. congressional hearing on environmental aspects of oil and gas development focused primarily on potentially beneficial, alternative usages of thousands of decommissioned offshore oil and gas platforms in the Gulf of Mexico, and elsewhere. These platforms and associated rigs would be permitted to be used as artificial reefs for corals and fish populations, mariculture sites, and scientific research stations, under the Rigs to Reef Act, House Resolution 2654. The bill, introduced by Rep. David Vitter (R-Louisiana), currently is in referral in the Resources and in the Ways and Means committees of the House of Representatives.

Showstack, Randy

428

Fiji's largest marine reserve benefits reef sharks  

NASA Astrophysics Data System (ADS)

To provide more information about whether sharks benefit from no-take marine reserves, we quantified the relative abundance and biomass of reef sharks inside and outside of Namena, Fiji's largest reserve (60.6 km2). Using stereo baited remote underwater video systems (stereo-BRUVs), we found that the abundance and biomass of sharks was approximately two and four times greater in shallow and deep locations, respectively, within the Namena reserve compared to adjacent fished areas. The greater abundance and biomass of reef sharks inside Namena is likely a result of greater prey availability rather than protection from fishing. This study demonstrates that marine reserves can benefit sharks.

Goetze, J. S.; Fullwood, L. A. F.

2013-03-01

429

VISAR studies of a reefing line cutter  

SciTech Connect

The VISAR has been used to study the