Ocean Studies Introduction to Oceanography American Meteorological Society

1. Ocean StudiesIntroduction to OceanographyAmerican Meteorological Society Chapter 13 The Future of Ocean Science

2. Case in Point • The first phase of ocean exploration depended upon oceanographic ships that served as platforms for deployment of various types of instruments and later submersible vehicles for in situ measurements of seawater and the ocean floor. • Satellite sensors revolutionized study of the sea because of their capability to rapidly monitor most of the ocean surface production and wave height. • Many ocean scientists see on the horizon the beginnings of a fourth phase of ocean exploration: deep-sea cabled observatories. • A deep-sea cabled observatory is placed on the ocean floor and linked to a mainland facility by fiber-optic and power cables.

3. Case in Point Principal Phases of Ocean Exploration

4. Case in Point The NEPTUNE Ocean Observatory will collect data from cable-linked sensors located around and across the Juan de Fuca plate off the Pacific Northwest coast.

5. The Future of Ocean Science • Driving Question: • How are advances in technology improving our understanding of the ocean?

6. The Future of Ocean Science • In this chapter, we examine: • Humankind’s efforts to learn more about the ocean, that is, to map the ocean floor, measure the properties of seawater, and monitor marine life as we seek to understand ocean’s role in the Earth system • The history of exploration of the ocean • Where progress is being made, the challenges that remain, and how ocean scientists are seeking to answer questions that have so far gone unanswered

7. Investigating the Ocean • VOYAGES OF EXPLORATION • The earliest migrations of modern humans out of Africa began around 50,000 years ago. • Evidence of human migrations via the ocean is the widespread distribution of human populations. • Accounts of voyages and shipwrecks 2,000 years ago are found in the Bible and other works of comparable antiquity. • Oceanographic expeditions began with the three Pacific Ocean voyages of Captain James Cook of the British Royal Navy over the period 1768-1780. • Relied on the latest navigational tools to determine longitude accurately • Mapped the Southern Ocean as well as many other parts of the Pacific, “discovering” Australia, New Zealand, and the Hawaiian Islands • First to circumnavigate Earth at high latitudes and sailed as far south as about 70°S but did not sight Antarctica

8. Investigating the Ocean • VOYAGES OF EXPLORATION • Two early English explorers, Sir John Ross and his nephew Sir James Clark Ross, were interested in conditions in the deep ocean. • Discovered abundant marine animals living on the ocean bottom at great depths of water—an extreme environment previously believed to be devoid of all life • From 1831 to 1836, the HMS Beagle undertook a voyage to study the natural science of Galápagos Islands as well as many other locations. • Charles Darwin was onboard as a naturalist • Darwin correctly argued that the form and structure of reefs and atolls develop because they are living organisms growing upward in an effort to remain in the ocean’s photic zone as compensation for the sinking sea floor.

9. Investigating the Ocean • VOYAGES OF EXPLORATION • In 1838-42, the United States launched its Exploring Expedition, a two-pronged voyage in that it was primarily a naval expedition but had more scientific latitude than the British Challenger Expedition of 1872-76. • Goals included showing the flag, charting, whale watching, gathering geological specimens, and general scientific observations

10. Investigating the Ocean • VOYAGES OF EXPLORATION • Matthew Fontaine Maury (1806-73) began his naval career as a midshipman onboard the U.S. sloop-of-war Falmouth, serving as navigation officer. • Out of this work came more accurate navigation charts of winds and currents in the world ocean. • In 1855, Maury published The Physical Geography of the Sea, the first textbook on modern oceanography.

11. Investigating the Ocean • CHALLENGER EXPEDITION (1872-1876) • First voyage dedicated exclusively to marine science • Laid the foundation for modern ocean science • Tested the hypothesis that no life could exist below an ocean depth of 550 m (1800 ft) because of extreme pressure and no light • Proven false with a total of 4017 previously unknown species of marine animals and plants discovered to all depths • First systematic map of major ocean currents and water temperatures, a map of ocean bottom features, discovery of the Challenger Deep in the Mariana Trench in the Pacific Ocean, finding manganese nodules at the bottom of the North Atlantic, and documenting the great diversity of marine plants and animals, especially microscopic plankton • Most important product of the voyage was the 50-volume report of the expedition’s scientific findings, the Challenger Report, written and published between 1880 and 1895 by Sir John Murray

12. Investigating the Ocean Dredging and sounding equipment onboard the HMS Challenger. The 1872-76 Challenger Expedition laid the foundation for modern ocean science.

13. Modern Ocean Studies • TECHNOLOGICAL INNOVATIONS • The first major oceanographic expedition of the 20th century was the German Atlantic Ocean Expedition of 1925-27. • National defense needs during World War II and the subsequent Cold War spurred advances in ocean science and technology by the industrialized nations of the West and the Soviet Bloc. • Paralleling the increasing use of ships for ocean research was the design and development of piloted submersible vehicles that enabled scientists to observe the ocean depths directly. • Bathysphere, bathyscaph • Alvin, the world’s first deep-ocean research submersible, was built in 1964. • One of only five deep-sea research submersibles operating in the world today • Made possible the discovery of many important deep-sea features, including the first known hydrothermal vents and associated unique biological communities in the 1970s as well as locating the wreck of the RMS Titanic and many other ships

14. Modern Ocean Studies The USS Albatross of the United States Fish Commission carried out many expeditions throughout the world from 1887 to 1925 and discovered hundreds of marine species using surface townets and benthic trawls and dredges. Alvin

15. Modern Ocean Studies Alvin’s arm and claw grasp a sample of pillow basalt on the ocean floor. Research Vessel Atlantis moored at the Woods Hole Oceanographic Institution in Massachusetts. Atlantis is the support ship for the submersible Alvin.

16. Modern Ocean Studies • TECHNOLOGICAL INNOVATIONS • JASON, a remotely operated vehicle (ROV)capable of reaching a depth of 6000 m (19,685 ft) built in the late 1980’s • Retired in 2001 and replaced by JASON II the following year • Designed for routine operation at depths as great as 6500 m (21,325 ft), JASON II can remain on the ocean floor for days at a time • A major impetus for development of ocean instrumentation came from the offshore oil industry, which played a lead role in the design of ROVs.

17. TECHNOLOGICAL INNOVATIONS ROVs and Autonomous Underwater Vehicles (AUV) have greatly increased our knowledge of mid- and deep-water marine life. Modern Ocean Studies Launch of the ROV Innovator

18. Modern Ocean Studies • REMOTE SENSING • Acquisition of data on the properties of some object without the sensor being in direct contact with the object • Involves not only Earth-orbiting satellites, but also certain automated observing platforms • Observations are the basis for detecting and following the movements of water masses through the ocean, locating submarine volcanic eruptions, and tracking migrating whales

19. Modern Ocean Studies • SCIENTIFIC OCEAN DRILLING • Began in the early 1960s • Led to the Deep Sea Drilling Program (DSDP), which operated from 1968 to 1983 using the drill ship Glomar Challenger • Dynamical positioning permitted the ship to drill in deep waters without anchoring • In 1983, a larger and more capable drill ship, the JOIDES Resolution, using essentially the same technology continued deep sea drilling in the Ocean Drilling Program (ODP) (1983-2003)

20. Modern Ocean Studies • SCIENTIFIC OCEAN DRILLING • Many important scientific discoveries came out of the DSDP and ODP. • Verification of sea-floor spreading from analysis of rock samples recovered from the bottom of the North Atlantic • Deep-sea sediment cores yield a record of climate fluctuations as far back as about 190 million years ago. • In October 2003, the Integrated Ocean Drilling Program (IODP)began. • Goal to use two drill ships plus specialized drilling platforms rather than a single general-purpose ship and drill more and deeper holes on the ocean floor • Use of specialized drilling platforms for areas where drill ships could not safely or efficiently operate, such as in the Arctic multi-year sea ice • Will also add to our understanding of global climate change and earthquake generation

21. Modern Ocean Studies • SHIPS OF OPPORTUNITY • Oceanographic research ships are expensive to operate. • Specialized research vessels will always be in short supply. • Volunteer Observing Ships (VOS) • Ships already operating in the cargo and cruise ship fleets • Can be outfitted with instruments that record atmospheric conditions as well as sea-surface temperature and salinity • Some chemical properties of the ocean water are measured by VOS including, for example, the CO2 concentration of surface waters.

22. Modern Ocean Studies • INTERNATIONAL COOPERATION • International Geophysical Year (IGY) featured the first systematic hydrographic survey of the world ocean and provides the earliest baseline for large-scale changes in ocean temperature and salinity. • International Decade of Ocean Exploration (IDOE), 1970s • Organized the first modern systematic surveys of ocean currents and the chemical composition of seawater • Initiated field studies that eventually led to our present ability to monitor the evolution of El Niño and La Niña

23. AUTONOMOUS INSTRUMENTED PLATFORMS AND VEHICLES Buoys: small floating un-piloted platforms, typically several meters in diameter that are moored at fixed locations in the ocean Sensors take continual observations of the lower atmosphere and upper-ocean. Data are then transmitted to polar-orbiting satellites for transmission to computers ashore. Emerging Ocean-Sensing Technologies

24. Emerging Ocean-Sensing Technologies • AUTONOMOUS INSTRUMENTED PLATFORMS AND VEHICLES • Argo floats: cylindrical devices equipped with sensors that augment satellite-based observations of the ocean surface as well as buoy observations of the upper ocean • Obtain profiles of ocean temperature and salinity to depths as great as 2000 m (6600 ft) • Slocum glider • Covers greater distances and has a longer sampling life span than the Argo float • Sinks and rises through the ocean by changing its buoyancy • Measures temperature, conductivity (salinity), and other water properties at various depths • At regular intervals, the glider surfaces, determines its position by GPS, and relays the stored observational data via satellite

25. Emerging Ocean-Sensing Technologies • AUTONOMOUS INSTRUMENTED PLATFORMS AND VEHICLES • Autonomous Underwater Vehicles (AUVs):augment the capabilities of research submersibles and ROVs and move through ocean waters faster than gliders • Un-piloted and do not rely on a cable tethering them to a mother ship • Have sensors that measure ocean water properties along trajectories that can be pre-set or controlled while the AUV is underway • Can observe the ocean in places and under conditions where research ships and other instrumented platforms cannot

26. Emerging Ocean-Sensing Technologies Launch of ABE, an autonomous underwater vehicle (AUV) equipped with sensors to measure temperature, conductivity, magnetics, and multibeam bathymetry. Recovery of a side-scan sonar towfish used to map the Pearl Harbor Defense Area.

27. Emerging Ocean-Sensing Technologies • OCEAN FLOOR OBSERVATORIES • An instrumented facility that can perform experiments, collect data, and communicate observations to data networks and scientists worldwide • First generation of ocean floor observatories stored data that were retrieved during infrequent visits by surface ships or submersibles • With next generation of deep-sea cabled observatories, scientific inquiry can continue indefinitely as seafloor cables transmit in real-time a continuous stream of observational data to networks on land for widespread distribution.

28. Emerging Ocean-Sensing Technologies • OCEAN FLOOR OBSERVATORIES • Detailed studies of seismic waves generated by earthquakes worldwide require observations that are fairly uniformly spaced but most seismometers are land-based. • An innovative approach to observing remote areas of the ocean uses small, electronic instrument packages (tags) that are attached to free-swimming marine animals having strong homing instincts such as seals and whales. • Provide information on the animals’ movements as well as the environment in which they live

29. Emerging Ocean-Sensing Technologies • COMPUTERS AND NUMERICAL MODELS • Future advances will increasingly depend on access to the world’s largest and fastest computers. • One of the major achievements in the application of coupled air-sea numerical models is the prediction of the onset an evolution of El Niño and La Niña months in advance of the event. • Observational data acquired by an array of moored and drifting buoys in the tropical Pacific along with satellite and tide gauge data are used to initialize these numerical models.

30. Challenges in Ocean-SensingTechnologies • The essential requirement for understanding the global environment and its interactions with humans is a systematic record of observations of the Earth system and its sub-systems. • The ocean is under sampled both in space and time. • Much more observational data are needed and many problems remain to be solved.

31. Challenges in Ocean-SensingTechnologies • The coastal zone is perhaps an area where substantial advances in ocean-observing technology are most needed, in part because this is where the actual and potential impacts of human population pressures are most severe. • One emerging technology that may be useful in the coastal zone is remotely controlled ultra-light aircraft capable of flying low and making observations over extended periods. • Scientists are increasingly relying on high frequency radar to monitor surface currents in the coastal ocean. • This specialized radar system, known as CODAR (Coastal Ocean Dynamics Applications Radar), uses scattered radar waves to measure ocean surface wave speed. • Requires stable platforms and is typically used in coastal environments where the radar antenna towers can be positioned on land

32. Better technologies for studying marine life are needed. Most of the organisms living in the ocean are one-celled microbes, but many sampling techniques are designed for studying only those organisms that can be caught in nets, from large plankton up to the size of fish. Many of the new techniques to study marine microbes will probably come from advances in biotechnology. Challenges in Ocean-SensingTechnologies

33. Challenges in Ocean-SensingTechnologies • New microchips are needed to perform chemical analyses of compounds in seawater, including routine monitoring of essential nutrients, the fertilizers of the sea, as well as toxins released by harmful algal blooms. • Better knowledge of the ocean requires more accurate maps of the ocean floor. • Mapping the deep-ocean floor, begun by the Challenger Expedition, is still incomplete. • The best global map of ocean floor topography is obtained from satellite-borne radar (microwave) altimeters. • Measure the shape of the sea surface which is strongly influenced by Earth’s gravity field • Limited in fine-scale detail; the shape of the ocean surface tends to “blur” the details of very steep ocean ridges and trenches

34. Challenges in Ocean-SensingTechnologies • More complete mapping of the sea floor would yield numerous benefits: • Will permit refinement of plate-tectonic models • Permit better understanding of mixing processes in the deep ocean due to tidal currents flowing over features such as volcanic ridges or seamounts • Commercial applications of deep-ocean maps include determining the optimum sites for laying optical cables for communication networks and managing fishery resources in Exclusive Economic Zones • Tsunami prediction and hazard models would also benefit

35. Conclusions • With the development of reliable methods of navigation, ocean-going vessels provided access to all continents and commercially important trade routes were established. • Beginning with the Challenger Expedition of the 1870s, understanding of the ocean’s properties and processes rapidly grew during the 20th century and into the present century. • New knowledge was partially a product of peacetime application of technologies originally developed for national defense. It was also the result of innovative technologies either adapted from other fields or developed specifically for probing the ocean. • Although many challenges need to be overcome and many questions remain to be answered, humankind’s understanding of the role of the ocean in the Earth’s system is progressing at an encouraging pace.