Oceanography & the Challenger Expedition

A Canadian-Born Scot

John Murray was born on 3 March 1841 at Cobourg, on the north shore of Lake Ontario, in what was then Canada West. He was the second son of Robert Murray, an accountant, and Elizabeth Macfarlane, both of Scottish stock, who had crossed the Atlantic to Canada around 1834. Young John attended school in London, Ontario, and then Cobourg College — a thoroughly Canadian upbringing, and this article does not pretend otherwise.

Honesty matters here: Murray was Canadian by birth, not Scottish. But, like Peter Higgs (born in Newcastle) or Charlotte Auerbach (born in Germany) elsewhere in this collection, his life and scientific work belong to Scotland. In 1858, aged 17, he crossed the Atlantic again to live with his grandfather, John Macfarlane, in Stirling, completing his schooling at Stirling High School. He would later recall that his first sight of the tide rising and falling along the Scottish coast marked the beginning of his lifelong fascination with the sea.

In 1864 Murray enrolled at the University of Edinburgh, initially intending to study medicine, but he proved a restless and unconventional student and never completed a degree. In 1868 he shipped out as surgeon aboard the Arctic whaler Jan Mayen, spending seven months around Spitsbergen and Jan Mayen Island, collecting marine specimens and recording ice, currents and weather — his first real taste of ocean science. Back in Edinburgh, he studied geology under Sir Archibald Geikie and natural philosophy (physics) under Peter Guthrie Tait, even helping to design an electrical deep-sea thermometer. It was Tait who introduced Murray to Charles Wyville Thomson — the connection that would define the rest of his life.

The Voyage, 1872–1876

HMS Challenger was a steam-assisted Royal Navy Pearl-class corvette, launched in 1858 at Woolwich. For her new scientific mission, she was stripped of all but two of her guns and fitted out with laboratories, a dedicated dredging platform, microscopes, sounding lines and thousands of specimen jars — becoming, in effect, the world's first purpose-built oceanographic research vessel.

She departed Portsmouth on 21 December 1872 and returned to Spithead on 24 May 1876. In Wyville Thomson's own account of the voyage, "Between our departure from Sheerness on December 7th, 1872, and our arrival at Spithead on May 24th, 1876, we traversed a distance of 68,890 nautical miles" — about 127,580 kilometres — the ship having first moved from Sheerness dockyard before the scientific voyage proper began from Portsmouth. Scientific supervision was in the hands of Charles Wyville Thomson, a Scot born at Bonsyde, Linlithgow, West Lothian, on 5 March 1830 (not, as is sometimes mistakenly stated, in Derbyshire). His scientific team included Henry Nottidge Moseley, the German naturalist Rudolf von Willemoes-Suhm — who died during the voyage — the chemist John Young Buchanan, and Murray himself. Herbert Swire served as a navigating officer and John James Wild as secretary and artist. Command of the ship passed from Captain George Nares to Captain Frank Tourle Thomson during the voyage.

Murray was appointed one of the naturalists almost at the last moment, and it would be misleading to present him as the expedition's intellectual architect — that role belonged to Wyville Thomson. What Murray did demonstrate, from the outset, was an unusual capacity for systematic work: aboard ship he took charge of the biological specimens and the sea-floor sediments, helped improve the scientific instruments, and proved himself the most methodical and driven member of the scientific staff.

The working method was painstaking and repetitive by design. Roughly every 200 miles, the ship would heave to for the better part of a day to work a "station": lowering weighted lines to sound the depth and retrieve sediment samples from the bottom; dredging and trawling for living creatures; measuring water temperature at a series of depths; and drawing water samples for chemical analysis. According to a standard summary of the voyage, the expedition gathered observations from 362 stations, made 492 deep soundings and 133 dredgings, alongside 151 open-water trawls. The scientific haul was staggering: the voyage is credited with cataloguing more than 4,700 new species of marine animals — more ocean life described in four years than in all of previous science combined.

Sediment Classification

This is where Murray's personal scientific originality shines most clearly, independent of any question about the expedition's shared leadership. Working with the Belgian geologist Alphonse Renard, Murray produced the Report on Deep-Sea Deposits (1891), the first systematic account of the geology of the entire ocean floor. Before this work, only "globigerina ooze" — a calcareous sediment named earlier — had been formally described. Murray, by carefully towing fine-mesh nets to catch living surface plankton, proved that these calcareous oozes originated from the shells of surface-dwelling organisms that rained down onto the seabed after death. He went on to name the other great sediment types: radiolarian ooze, diatom ooze and pteropod ooze, each dominated by the remains of a different group of tiny organisms.

Most significant of all was his identification and naming of "red clay" — the fine, brownish sediment that blankets the deepest and most remote parts of the ocean floor, far from any continental source of sediment. It is essential to be precise about how this material forms, because it is easily misunderstood: red clay is not simply material "carried in" and deposited by deep ocean currents, as a casual glance at a simplified seabed diagram might suggest. Murray's own explanation, which still stands more than a century later, was that this sediment forms because the calcium-carbonate shells of surface-dwelling plankton dissolve before they can reach the ocean floor at these extreme depths — a boundary that oceanographers now call the carbonate compensation depth. Below it, seawater is corrosive enough that calcareous material simply does not survive the long fall to the bottom. What accumulates instead, extremely slowly, is chiefly fine volcanic ash and dust that has blown out over the ocean from land and from volcanic activity, along with a small quantity of extraterrestrial dust — not calcareous material swept along by currents, but the residue left behind once the calcareous fraction has quietly dissolved away. Murray was effectively the first to identify what is now formally termed the carbonate compensation depth, decades before the chemistry of ocean-water carbonate saturation was properly understood.

This body of work — patient, comparative, built on carefully controlled sampling rather than speculation — is arguably a better guide to what made Murray a great scientist than his more famous role editing the Report. It is original, it is his, and it has proved durable.

The Ridge and the Nodules

From the pattern of Challenger's soundings, Murray was among the first scientists to recognise that the floor of the Atlantic was not a featureless bowl, as had generally been assumed, but rose along its centre into a great submarine ridge, while elsewhere the sea floor plunged into deep trenches. He is widely credited as the first to note the existence of what is now called the Mid-Atlantic Ridge. It is important to state the limits of this claim precisely: its full significance — that mid-ocean ridges are the sites where new ocean floor is continuously created — was not understood until the theory of seafloor spreading and plate tectonics emerged in the 1960s, more than 80 years after Murray's observations. What Murray had done was glimpse the outline of a living, moving planet, without yet possessing the theoretical framework to explain what he was seeing.

Challenger's dredges also brought up curious dark, rounded lumps, ranging from marble to potato size, scattered across the deep ocean floor, especially in the red-clay regions of the Pacific. Murray and Renard analysed these as concretions of manganese and iron oxides, laced with copper, nickel and cobalt. John Young Buchanan, the expedition's chemist, spotted their possible commercial value as early as 1874. Today these polymetallic nodules sit at the centre of a fierce global argument over deep-sea mining, prized for the very battery and electronics metals they contain. In fairness to the historical record, shallow-water manganese nodules had already been dredged by a Swedish expedition in the Kara Sea in 1868; it was Murray and Renard's Challenger description, though, that made the phenomenon known to the wider scientific world.

Antarctica and Scotland's Lochs

Murray became a passionate advocate for polar science, even though he never travelled south himself. On 27 November 1893 he delivered a landmark address to the Royal Geographical Society titled "The Renewal of Antarctic Exploration." A contemporary report of the lecture recorded Murray's argument that "the probability is that around the South Pole a land area of about 4,000,000 square miles actually exists," and his call for a full British expedition to investigate it. That lecture, subsequently published in the Geographical Journal in 1894, is widely credited as a spark for the "Heroic Age" of Antarctic exploration that followed over the next two decades.

Murray never neglected home waters either. In 1884 he established the Marine Laboratory at Granton on the Firth of Forth — the first marine laboratory of its kind in the United Kingdom — which later moved to Millport and became a forerunner of today's Scottish Association for Marine Science.

Perhaps his most quietly monumental achievement, and one that receives less popular attention than Challenger, is the Bathymetrical Survey of the Fresh-Water Lochs of Scotland, published in six volumes in 1910, the fruit of a survey conducted between 1897 and 1909. According to the National Library of Scotland's Bartholomew Archive, the survey involved taking "60,000 soundings of 562 major Scottish lakes." The work was funded with £10,000 from Laurence Pullar, whose son and Murray's collaborator, Frederick Pullar, had drowned in an ice-skating accident in January 1901; its 223 coloured maps were drafted by the great Edinburgh cartographer John George Bartholomew. It stands, on its own terms, as a monumental achievement of Scottish natural science, entirely independent of the Challenger story.

The 50-Volume Report

Charles Wyville Thomson, worn down by the crushing labour of organising Challenger's vast results, died on 10 March 1882. It is at this point in the story that Murray's role shifts decisively from junior naturalist to central figure. Pressed forward by the Royal Society, Murray took over as director of the Challenger Office in Edinburgh and editor of the reports.

The result was the Report on the Scientific Results of the Voyage of H.M.S. Challenger, published between 1880 and 1895: 50 immense volumes, each reportedly as thick as a family Bible, running to some 30,000 pages, drawing on the labour of a large international body of scientists — over 75 report authors from Britain, Europe and the United States, part of a wider group of more than a hundred scientists who examined the collected material. Murray did not merely edit; he remained an active working scientist throughout, writing seven of the volumes largely or entirely himself, including the Deep-Sea Deposits volume and the two-volume Summary of 1895. When the Treasury attempted to end funding for the project in 1889, Murray fought to save it and completed some of the later work partly at his own expense. He described the whole enterprise, with justified pride, as "the greatest advance in the knowledge of our planet since the celebrated discoveries of the fifteenth and sixteenth centuries."

The Report was extraordinarily costly to produce, funded by repeated five-year Treasury grants stretched over nearly two decades. A figure of £68,000 is sometimes quoted for its total cost, and it is often claimed that the Report cost more than the voyage itself; this article treats both specific claims with appropriate caution, since they could not be verified against authoritative primary sources, and the expedition itself — with a parliamentary allocation on the order of £200,000 — was already a very substantial undertaking in its own right.

Later Life and Death

In 1910 Murray organised one last great scientific cruise. He persuaded the Norwegian government to lend their fisheries research steamer Michael Sars for a four-month North Atlantic expedition, under the scientific command of the Norwegian marine biologist Johan Hjort (1869–1948), with Murray personally paying all the expenses. From it came The Depths of the Ocean (Macmillan, London, 1912), an 821-page synthesis of the whole science of oceanography as it then stood. It became the standard textbook of the field for a generation, and it reaffirmed, decisively, that the ocean floor teems with life — the final burial of Edward Forbes's long-dead azoic hypothesis.

Murray was showered with honours across his later career. He received the Royal Society's Royal Medal in 1895, was elected a Fellow of the Royal Society in June 1896, and was made a Knight Commander of the Order of the Bath (KCB) in 1898. He served as president of the Royal Scottish Geographical Society (1898–1904) and received its Livingstone Medal in 1910, along with a string of foreign honours. His personal fortune — made largely from phosphate mining on Christmas Island, whose deposits he had predicted from Challenger specimens decades earlier — helped fund much of his later independent research.

He lived at Challenger Lodge in Edinburgh, now St Columba's Hospice. On 16 March 1914 he was killed when his car overturned about ten miles west of his home, at Kirkliston, West Lothian. He had just turned 73, and he was buried in Dean Cemetery, Edinburgh — a sudden, poignant end for a man who had devoted his entire life to peaceful scientific discovery, just months before the outbreak of the First World War.

Modern Legacy

HMS Challenger's reach still echoes clearly today. Its deepest sounding — 4,475 fathoms, about 8,184 metres, taken on 23 March 1875 south-west of the Mariana Islands — first hinted at what we now know as the deepest place on Earth's oceans, the Challenger Deep, named after the ship and now measured at nearly 11,000 metres. Murray himself drew the map that first labelled it. The manganese nodules he and Renard described are now the subject of intense commercial and environmental argument over deep-sea mining. His early, tentative recognition of the Mid-Atlantic Ridge foreshadowed the plate-tectonic revolution of the 1960s by more than eighty years. The ship's name even carried into space: NASA's Space Shuttle Challenger was named directly after HMS Challenger.

A submarine ridge in the northern Arabian Sea, the Murray Ridge — discovered on the 1933–34 John Murray Expedition, endowed by his estate — bears his name, as do the John Murray Laboratories at the University of Edinburgh and a blind deep-sea octopus, Cirrothauma murrayi. Above all, though, Murray's most durable legacy is methodological: he established oceanography as a rigorous, classificatory science, with systematic sampling methods and naming conventions that endure in modern research, even as hand-hauled dredges have given way to sonar seabed mapping, submersibles capable of visiting hydrothermal vents, and satellites that monitor the entire planet's oceans continuously from orbit.

Timeline

1. 1841

   John Murray born at Cobourg, Canada West, to Scottish emigrant parents

   He was Canadian by birth, not Scottish — an honest point this article does not obscure

2. 1843

   Edward Forbes proposes the 'azoic hypothesis'

   Argues deep-sea life ceases below about 300 fathoms — later shown to be wrong, but scientific orthodoxy for a generation

3. 1855

   Matthew Fontaine Maury publishes The Physical Geography of the Sea

   The first modern oceanographic textbook, but focused on surface currents and winds, not the deep sea

4. 1858

   Murray, aged 17, emigrates to Scotland to live with his grandfather in Stirling

   The beginning of a scientific life spent entirely in Scotland

5. 1864

   Murray enrols at the University of Edinburgh to study medicine

   He never completed a degree, but studied geology under Archibald Geikie and physics under Peter Guthrie Tait

6. 1868

   Murray sails as ship's surgeon on the Arctic whaler Jan Mayen

   Seven months collecting marine specimens near Spitsbergen — his first taste of ocean science

7. 1868–1870

   HMS Lightning and HMS Porcupine dredge the deep sea off Scotland

   Wyville Thomson and William Carpenter disprove Forbes's azoic zone, finding abundant life far below his supposed limit

8. 21 December 1872

   HMS Challenger departs Portsmouth

   The start of the four-year voyage that founded oceanography as a systematic science

9. 1872

   Murray is appointed a Challenger naturalist almost at the last moment

   One of several scientists aboard under chief scientist Charles Wyville Thomson

10. 23 March 1875

    Challenger records its deepest sounding, 4,475 fathoms south-west of the Mariana Islands

    The first hint of what is now known as the Challenger Deep, named after the ship

11. 24 May 1876

    HMS Challenger returns to Spithead

    68,890 nautical miles sailed; over 4,700 new species catalogued from 362 stations

12. 1880–1895

    The 50-volume Challenger Report is published

    Murray takes over as editor after Wyville Thomson's death in 1882, writing seven volumes largely himself

13. 1882

    Charles Wyville Thomson dies

    Murray becomes director of the Challenger Office in Edinburgh and editor-in-chief of the Report

14. 1884

    Murray founds the Marine Laboratory at Granton

    The first marine laboratory in the United Kingdom, forerunner of the Scottish Association for Marine Science

15. 1891

    Murray and Alphonse Renard publish Report on Deep-Sea Deposits

    The first systematic geological classification of the entire sea bed, naming radiolarian, diatom, pteropod ooze and red clay

16. 1893

    Murray addresses the Royal Geographical Society on Antarctic exploration

    Widely credited as a spark for the 'Heroic Age' of Antarctic exploration that followed

17. 1895

    Murray receives the Royal Society's Royal Medal

    Recognition of his contribution to the completed Challenger Report

18. 1896

    Murray elected Fellow of the Royal Society

    Formal scientific recognition

19. 1897–1909

    Murray conducts the Bathymetrical Survey of the Fresh-Water Lochs of Scotland

    60,000 soundings of 562 Scottish lochs, published in six volumes in 1910

20. 1898

    Murray made Knight Commander of the Order of the Bath (KCB)

    National honour for his scientific work

21. 1910

    Murray funds and organises the Michael Sars North Atlantic expedition

    Under Norwegian scientist Johan Hjort; results published as The Depths of the Ocean, 1912

22. 16 March 1914

    Murray dies near Kirkliston, West Lothian, aged 73

    Killed when his car overturned, months before the outbreak of the First World War

23. 1933–34

    The John Murray Expedition, endowed by his estate, discovers a submarine ridge in the Arabian Sea

    Named the Murray Ridge in his honour

24. 1960s

    Plate tectonics and seafloor spreading theory emerge

    Confirms the significance of features like the Mid-Atlantic Ridge that Murray had been among the first to note, 80 years earlier

Myths & Facts

Did You Know?

• Murray was born in Canada but returned to Scotland as a teenager and gave his entire scientific life to Edinburgh and the sea — a Scot by upbringing, not by birth.
• The Challenger expedition described over 4,700 new species in four years — more marine life than had been catalogued in all previous ocean science combined.
• The Challenger Report Murray completed after Wyville Thomson's death ran to 50 volumes and around 30,000 pages, an editorial marathon lasting to 1895.
• Murray was killed in a car accident in 1914, aged 73, just months before the First World War — a poignant end for a man devoted to peaceful discovery.
• The deepest point in the ocean, the Challenger Deep in the Mariana Trench, is named after his ship, and NASA's Space Shuttle Challenger was named after it in turn.
• The manganese nodules Murray described in the 1870s are now at the centre of a global controversy over deep-sea mining.
• Between 1897 and 1909, Murray also took 60,000 soundings of 562 Scottish freshwater lochs — a monumental survey largely separate from his ocean work.

Honest Caveats

The Challenger expedition's scientific leadership belongs to Charles Wyville Thomson, not Murray. Murray was one of several naturalists aboard, appointed almost at the last moment. Presenting him as the expedition's founder or leader would misstate the historical record.

"Father of oceanography" is an honorific, not a precise title. It is widely repeated and defensible given Murray's later contributions, but oceanography was built by many hands, including Maury, Forbes, Carpenter and Wyville Thomson.

Sources disagree on minor numbers. The Challenger's crew complement is variously given as 237, 243 or roughly 250; and, depending on how one counts, Murray was 72 or 73 at his death (born 3 March 1841, died 16 March 1914 — so he had just turned 73).

Priority for manganese nodules is contested. Shallow-water nodules had already been dredged by a Swedish expedition in the Kara Sea in 1868, though Murray and Renard's Challenger description is the scientifically foundational one.

The £68,000 Report-cost figure, and the claim that it exceeded the voyage's cost, could not be confirmed against authoritative primary sources and should be treated with caution; the expedition's own parliamentary allocation is cited at roughly £200,000.

The voyage's departure and return dates require care. The voyage is properly dated from Portsmouth (21 December 1872) to Spithead (24 May 1876); the frequently seen "Sheerness, 7 December 1872" refers to the ship's initial move out of dockyard before the scientific voyage proper began.