Ocean Studies
Introduction to Oceanography
American Meteorological Society
Chapter 13
The Future of Ocean Science
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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.
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Case in Point
Principal Phases of Ocean Exploration
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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.
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The Future of Ocean Science
• Driving Question:
– How are advances in technology improving
our understanding of the ocean?
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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
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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
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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.
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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
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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.
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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
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Investigating the Ocean
Dredging and
sounding equipment
onboard the HMS
Challenger. The
1872-76 Challenger
Expedition laid the
foundation for
modern ocean
science.
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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.
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– 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
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.
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Alvin
Modern Ocean Studies
Research Vessel Atlantis
moored at the Woods Hole
Oceanographic Institution in
Massachusetts. Atlantis is
the support ship for the
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submersible Alvin.
Alvin’s arm and claw grasp a
sample of pillow basalt on the
ocean floor.
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.
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Modern Ocean Studies
• TECHNOLOGICAL
INNOVATIONS
– ROVs and
Autonomous
Underwater
Vehicles (AUV)
have greatly
increased our
knowledge of midand deep-water
marine life.
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Launch of the ROV Innovator
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
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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)
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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
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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.
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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
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Emerging Ocean-Sensing
Technologies
• 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 upperocean.
• Data are then transmitted to polarorbiting satellites for transmission to
computers ashore.
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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
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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
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Emerging Ocean-Sensing
Technologies
Launch of ABE, an autonomous
underwater vehicle (AUV)
equipped with sensors to
measure temperature,
conductivity, magnetics, and
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bathymetry.
Recovery of a side-scan
sonar towfish used to map
the Pearl Harbor Defense
Area.
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.
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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
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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.
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Challenges in Ocean-Sensing
Technologies
– 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.
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Challenges in Ocean-Sensing
Technologies
– 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
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Challenges in Ocean-Sensing
Technologies
– 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.
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Challenges in Ocean-Sensing
Technologies
– 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
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Challenges in Ocean-Sensing
Technologies
– 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
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Conclusions
– With the development of reliable methods of navigation, oceangoing 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.
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