Tegan’s Science Notes #11: Voyages of Discovery

citizenscienceThe ocean is one of the last unexplored frontiers on earth. We know more about the surface of Mars than we do about the bottom of the ocean. For thousands of years, humans have been undertaking voyages of discovery. Whether the goal has been to find land beyond the horizon, to map the ocean currents or to find new animals unknown to science, the ocean has always been and will continue to be a deep source of knowledge which will always change the way we view and understand the world around us.

Today, science is moving in many new directions at once, and a great civic awakening is happening as everyday people armed only with some time and a passion to explore begin to help shape the future of scientific discovery. I have spoken many times in my previous “Science Notes” about what’s happening in the area of “Citizen Science,” but in this post, in recognition of Dave’s incredible feat of single handedly circumnavigating the globe, I’d like to look back at the relatively brief history of oceanic exploration.

The Great Voyages

Until quite recently scientific knowledge of the oceans was very limited. During the 1700s and 1800s, the British Royal Navy dominated the world’s oceans, which made surveying coastlines and mapping the oceans a practical priority for both the navy and for commerce. It was during this period that accurate navigation (and mapmaking) became gradually more dependable in locating precise positions on the earth, using a combination of latitude and longitude, celestial readings and chronometers. Many of these survey voyages carried additional passengers who acted as naturalists collecting botanical, biological, and geological samples which greatly expanded European scientific knowledge of the natural world.


The most famous of these ‘gentlemen naturalists’ was Charles Darwin. I referenced him before in my science note on glaciers, as he was first and foremost a geologist. Over the course of the five years from 1831-1836 that the HMS Beagle surveyed the coastlines of the southern part of South America and tested the accuracy of 22 chronometers at pre-determined points, Darwin was collecting copious observations and samples of geological, biological and botanical nature in these far-fling regions. It was Darwin’s unique ability to weave his observations together into a theoretical whole that so challenged the accepted thought of the day and elevated the Beagle’s second voyage into one of the most famous scientific voyages made in history.

darwin_200Nearly 40 years after Darwin sailed on the Beagle, a dedicated scientific expedition set off on board the HMS Challenger with the aim “to learn everything about the sea,” – a lofty goal indeed! Findings from this Challenger Expedition laid the groundwork for what would become the science of oceanography. Over the course of five years, Challenger traveled over 70,000 nautical miles conducting scientific exploration with freshly designed equipment and discovering over 4,000 new species of plants and animals.

Mapping the Ocean

captain_cook_200No one person has explored and mapped more of the ocean than James Cook. Captain Cook came from humble origins but his skill at mapmaking and navigation led him in 1769 to be put in command of the HMS Endeavour on an expedition to Tahiti to observe the transit of Venus across the Sun. Cook’s mapmaking skills were so accurate that an early map of Newfoundland was used for more than 200 years after he drew it and differs little from modern satellite images.

cookmap_300After visiting Tahiti, the Endeavour continued west to locate the famed “Terra Australis.” There Cook mapped the entire coastline of New Zealand before continuing east to Australia as the first European to land there. Over the next 12 years, Cook would make three voyages on board the HMS Endeavour and HMS Resolution, which explored and mapped previously uncharted areas of the world. As well as providing accurate charts for navigation, Cook’s expeditions also carried scientists who made important observations, especially related to botanical discoveries.

newport_300There is a second special connection of Captain Cook’s expeditions to Bodacious Dream. Both his ships, the HMS Endeavour and HMS Resolution are fairly certainly believed to lie as wrecks at the bottom of Narragansett Bay! The Endeavour, after coming out of Cook’s service, was renamed the Lord Sandwich and is one of several vessels which were sunk to blockade Newport Harbor during the American Revolutionary War. The HMS Resolution was sold and rechristened La Liberté, a French whaling vessel, which was damaged in Newport Harbor in the 1790s and left on the shore. Efforts are ongoing by the Rhode Island Marine Archaeology Project (RIMAP) to map and locate not only the Endeavour but also other shipwrecks in Rhode Island waters. You can visit their very informative website, and learn about RIMAP’s work right here, or go to the page on the sunken ships here.

Marshall Island Stick Charts

stick_chart_300Not all voyages of discoveries (that we know about) were made by Europeans. The Polynesians and Pacific Islanders had been navigating the South Pacific for thousands of years and likely explored the entire region, an area of over 10 million square miles, well before the period of written history. Along the way, they developed a complex system of navigation, which used stars, the sun, the moon, planets, weather, winds, currents, tides, and natural phenomena like bird migration to help them to travel between the many islands.

An important addition to the history of ocean mapping was the discovery of “stick charts” used by seafarers from the Marshall Islands. These are deceptively simple grids made from small sticks and coconut fronds, which represent the major ocean swells in the South Pacific, with small shells showing the location of islands. The charts showed how the swells interacted with the island shores, the undersea slopes, and currents coming from different directions. While the stick maps were easy to construct, it took many years of study to be able to accurately interpret the real ocean dynamics which they represented.

Mapping the Gulf Stream

As you are well aware from Dave’s journey, the Gulf Stream is a major current in the North Atlantic, which carries warm water from the Caribbean north to the northeast Atlantic and is the strongest surface current in the Atlantic. The impact that the Gulf Stream can have on the length of voyages is tremendous. The first reference to the Gulf Stream is found in a written account of Ponce de Leon’s voyage from Puerto Rico in 1513. American fishermen and whalers plying the waters off the American colonies knew of the current in the late 1600s.

franklin_300It actually took the insights of none other than Benjamin Franklin, the colonial deputy Postmaster General to make clear the existence of the Gulf Stream when in 1769 he published a chart that showed the direction of the flows. His chart of that time is still remarkably accurate. You can read more of Franklin’s very interesting writing about the Gulf Stream and other marine topics in NOAA’s historical archive right here.

Pathfinder of the Seas

Before the late 1800s, there were few comprehensive charts that showed wind and currents across the whole globe. This changed owing to the efforts of one man, Matthew Fontaine Maury.

maury_200Maury joined the US Navy as a young man in 1825 and was posted to the Naval Observatory in 1842, where he began to study ocean currents. By studying and compiling thousands of ships logs he was able to map and calculate the speed of ocean currents based on the deflection of ships from their intended path. He was able to produce maps of average ocean speeds for much of the ocean, which allowed vessels to dramatically reduce the length of their voyages. Maury was nicknamed the “Pathfinder of the Seas” and was integral to the creation of international cooperation in producing accurate hydrological charts for all mariners. He is also referred to as the father of the modern oceanography as well, and his book, The Physical Geography of the Sea, published in 1855, is one of the first books on oceanography.

Modern ocean mapping: Satellites, robots and sonar


Even today, we have only begun to map the ocean. Fortunately, today we have technologies that help us to see below the waves, to scan the ocean floor, to analyze the composition of the water, and to observe how the currents work in real-time. Satellites use the reflectivity of the ocean surface to measure chlorophyll content and sea surface temperature changes. Unmanned robots explore the depth of the ocean collecting readings of temperature, pressure, and salinity. Sonar is used to create high-definition maps of the sea floor. Computers are used to model the movement of currents, the future conditions under changes to currents, temperature and sea level.

Check out these cool websites: Perpetual Ocean and Ocean Motion.

“Standing on the shoulders of giants”

Modern science knows so much more and can do some much more than our predecessors could ever have imagined, but our greater knowledge is only possible because of the amazing feats of those ‘giants’ who set off to explore the world and to challenge the commonly held beliefs and superstitions of their day.

Darwin and the rest, they figured out how the world worked in a more complete sense. Today we are finding out how in flux the natural world is, and how delicate is the balance necessary to sustain life. We now can see with factual accuracy just how fast the natural world is changing.

Every observation Dave logged on iNaturalist (click to see all his sightings listed) or eBird is an important scientific finding, which adds to the wealth of scientific knowledge, now being collected by citizen scientists all over the world. Collecting the type of data needed to understand the broad scale patterns of change occurring all over the globe is increasingly difficult for individual scientists to collect on their own, but by relying on citizens (like you!) to help collect this vital information, it becomes easier to approach important questions.

No matter who or where you are, YOU too can be a scientist!


Join an Earthwatch Expedition. Join iNaturalist or eBird yourself and start tracking what you see around you.

LOGOS2Build a Secchi Disk and use the Secchi App to record your data. Download the mPing App and record your weather. Join Zooniverse and be a scientist from the comfort of your couch. The possibilities are endless!

Explore, discover, and most importantly… have fun!!

For myself, I would like to say that I have had a great time sharing my enthusiasm for the natural world with all of you over the past nine months. Thank you to those of you who reached out and contacted me with thoughts or questions. Keep the Bodacious Dream going and get out and discover!

Wishing you fair winds and following seas,

- Tegan Mortimer