Category Archives: History

Waves Across the Pacific

Claudia Schreier is a sophomore at the University of Delaware. She majors in Chemical Engineering with a minor in Marine Sciences. Ms. Schreier’s essay emerged from an assignment in an undergraduate “Introduction to Ocean Science” class taught by Drs. K. Billups and A. Muenchow in the fall of 2020. ~A. Muenchow, Editor

The 1967 documentary “Waves Across the Pacific” highlights some of the first uses of high-tech measuring tools and novel techniques to discover how waves move across the Pacific Ocean. Dr. Walter Munk and his research team studied how wave energy from storms off Antarctica is lost as waves move across the equator towards Alaska. This was the first time that anyone collected and reported data for wave processes on a global scale.

Dr. Munk in 1963 (UC San Diego Library)

The vessel that the team used for this expedition was fascinating; it is called FLIP, and it is a mobile floating instrument platform standing 355 feet tall, providing both the space and stability for the laboratory and its equipment. Waves originating from Antarctica reached New Zealand, and then moved farther in every direction within the Pacific Ocean. Recording stations were located in New Zealand, Samoa, Palmyra (an uninhabited equatorial atoll), Hawaii, and Alaska. In the North Pacific without suitable islands between Hawaii and Alaska, FLIP was used for wave measurements. Dr. Munk’s headquarters and central wave station for the experiment was in Honolulu, Hawaii.

The Floating Instrument Platform (Smithsonian Ocean)

Dr. Munk originally hypothesized that most of the wave energy coming from Antarctica would be scattered in the equatorial Trade Wind regions, therefore preventing most Antarctic waves from reaching the North Pacific. However, the data revealed little energy loss as the waves crossed the equator. The team discovered, though, that wave attenuation, or the loss of energy, results from interactions of waves from the same storm near its generation region off Antarctica only. Furthermore, the interactions between such waves weakened as they traveled away from the generation region through wave dispersion. This means that waves of different frequencies can travel at different speeds, therefore sorting them, because long waves move faster than shorter ones. Because of this data and new understanding, Dr. Munk could predict surfing conditions in Hawaii from prior observations off Samoa! The data and methodology from this experiment became the cornerstone of many subsequent studies to predict waves.

Recording stations from the study (Munk 2013)

The documentary film captured not only research methods but also life in the 1960s. I appreciated this look back in time, and it got me thinking about women in ocean sciences. In the film, all of the research scientists were men, and no women participated in the project whatsoever. The scientific community has come a long way since then, with more women participating and leading in both science and technology, as well as leading their fields, than ever before. The film helped me to realize that my interest in science and the opportunities to pursue a career within it has been aided by the efforts of countless women who have come before me.

This documentary also made me hopeful in a curious way that I did not expect from a marine science documentary. Dr. Munk was unsure about many things in this study, including the novel technology, remote measuring locations, and even the validity of the experiment itself. Amassing over 10 million data points, he found both the purpose and the results he was seeking for this research in the face of uncertainty. This documentary gave me a fresh take on ocean sciences, and it does more than just explain the brilliant research done in the 1960s: there are still many things we do not know about the world, but with the spirit and drive of Dr. Munk, there is no limit to what can be discovered.

A link to the film: https://waltermunkfoundation.org/uncategorized/waves-across-the-pacific/

Waves

Almost 300 years ago a brave scientist boldly stated that everything can be described as waves. It took mathematicians another 200 years to prove that Joseph Fourier, the bold scientist, had it right. I am comforted by this fact while the Covid-19 pandemic appears to grow without bounds. And yet, bounds do exist, because Fourier states that what goes up must come down. This includes the global Covid-19 pandemic of 2020/21 as well as the Influenza pandemic of 1918/19. The latter had three distinct peaks in the United Kingdom that varied both in amplitude and duration:

Adapted from Taubenberger, J.K. and D.M. Morens: 1918 Influenza: The mother of all pandemics, Emerging Infectious Diseases, 12 (1), 2006.

This pandemic of 100 years ago came in three distinct pulses in the spring of 1918, in the fall of 1918, and in the winter of 1919. The graph shows that during the first wave about 0.5% of all infected people died while the second and third wave were more deadly with 2.5% and 1.3% fatality rates. These rates are somewhat similar to those we see today with Covid-19, but there is much we do not yet know.

We do not yet know, for example, how long it will take for the Covid-19 waves to pass through populations. We do not know the amplitude of the waves either, because it all depends on how well we distance ourselves from each other both now and into the future to minimize transmission of the virus. There is no control, yet, because no vaccine exist, but smart distancing will impact how many people will get infected (the amplitude) over time (the period).

These two factors (amplitude and duration) will determine how many of our friends, partners, parents, brothers, and sisters we will lose to the virus. As the German Chancellor Angela Merkel said yesterday: “Im Moment ist nur Abstand Ausdruck von Fuersorge,” which translates as “At the moment only distance is an expression of care.”

German Chancellor Angela Merkel on Mar.-18, 2020 on German TV.

Waves change as they propagate from one medium to another. As ocean wave forms move from deep to shallow water they change both amplitude and speed until they eventually break. I view today’s Covid-19 waves in a similar way.

Covid-19 waves will propagate through all societies on our planet, but they will propagate differently in different regions, countries, and societies. Amplitudes, periods, and propagation speeds will differ. Some of this is already visible by global statistics that are collected and shared in real time:

From https://informationisbeautiful.net/visualizations/covid-19-coronavirus-infographic-datapack/

The spread of the virus in China differs from that in South Korea which differs from that in Iran, Italy, Germany, and the United States. Different political systems, different skills of and trust in governments, and different personal behaviors all provide a different medium within which these waves propagate and, eventually, will dissipate.

This is day-8 for me and my wife to distance ourselves from our friends, family, and neighbors. We are fine. My wife turns the bedroom into a painted mural while I read and write at home and spent much time in the spring garden. It slowly sinks in, that this will not be over next week or next month. The goal is to make the amplitude as small as possible by spreading the period out as long as possible which will allow our hospitals, nurses, and doctors to provide the best care for those who need it. As a wise woman said yesterday: “At the moment only distance is an expression of care.”

Reference:

Taubenberger, J.K. and D.M. Morens: 1918 Influenza: The mother of all pandemics, Emerging Infectious Diseases, www.cdc.gov/eid, 12 (1), 2006.”

How big is Greenland?

Maps of Greenland were sketched with broken bones, frozen limbs, and starved bodies of men and dogs alike. On April 10, 1912 four men and 53 sled dogs crossed North Greenland from a small Inuit settlement on the West Coast where today the US Air Force maintains Thule Air Base. In 1912 Knud Rassmussen, Peter Freuchen, Uvidloriaq, and Inukitsoq searched for two explorers lost somewhere on Greenland’s East Coast 1200 km (760 miles) away. They returned 5 months later with 8 dogs without finding Einar Mikkelsen or Iver Iversen. These two arrived in North-East Greenland to find diaries, maps, and photos of three earlier explorers who had starved to death in the fall of 1908. Mikkelsen and Iverson found the records, but struggled to survive the winters of 1910/11 and 1911/12 alone stranded before a passing ship found them. I ordered their 1913 Expedition Report yesterday.

Dog sled teams drive across Greenland’s Inland ice in April 1912 from Clemens Markham’s Glacier in the west to Denmark Fjord in the east. All 4 explorers returned, but only 8 dogs did.
Map of Greenland as included in the Report of the First Thule Expedition 1912 by Knud Rasmussen.

I worked along these coasts in 2014, 2015, 2016, 2017, and 2018 on German research vessels, Swedish icebreakers, Greenland Air helicopters, and American snowmobiles. We explored the oceans below ice and glaciers with digital sensors but without hunger, cold, or lack of comfort. I feel that I know these coasts well, read what others have written and suffered. I make my own maps, too, to reveal patterns of oceans, ice, and glaciers that change in space and time. And yet, I am often lost by distances and areas. I do not know how big Greenland is.

Clockwise from top left: Ocean observatory on sea ice off Thule Air Base (Apr.-2017); refuelling helicopter in transit to ocean observatory on Petermann Gletscher (Aug.-2016); Swedish icebreaker in Baffin Bay (Aug.-2015); and deployment of University of Delaware ocean moorings from Germany’s R/V Polarstern off North-East Greenland at 77 N latitude (Jun.-2014).

At home I know distances that I walk, bicycle, or drive as part of my daily routine. I know areas where I live from weather and google maps, weekend strolls, and where family and friends live. Once we travel in unfamiliar lands, however, we are lost. Americans rarely know how small most European countries are while Europeans rarely know how far the Americas stretch from Pacific to Atlantic Oceans. Nobody knows the size of Greenland or Africa. On World Atlases Greenland appears as large as Africa, but this is false. Just look at this map:

The size of Africa on the same scale as the USA (green), Greenland (orange), and Germany (blue). Germany is about the same size as Botswana while Greenland is a tad larger than Kongo and the USA is about as big as the Sahara.

Thus North Greenland’s explorers walked distances similar to walking across Texas, Mississippi, and Florida (and back) or distances similar to walking Germany from its North Sea to the Alps (and back) or distances similar to walking across Kenya (and back). Making these maps, I found the tool at https://thetruesize.com These playful maps compare Greenland’s size by placing its shape onto North-America, Europe, and Asia:

Three explorers starved and froze to death November 1907 because they underestimated their walking area. Their shoes wore thin and they walked barefoot. Daylight disappeared and was replaced by polar night. Food vanished with no game to hunt. Jorgen Bronland, Niels Hoeg Hagen, and Ludvig Mylius-Erichsen were 29, 30, and 35 years young when they died mapping Greenland. I sailed the ice-covered coastal ocean. I was helped by maps they made walking.

Scoresby Sund – Greenland’s Longest Fjord

Fog, fog, and more fog is all we saw as we approached Scoresby Sund aboard the German research ship Maria S. Merian from Denmark Strait to the south-east. The fog lifted as soon as we passed Kap Brewster and began work on ocean currents and waters at the entrance of this massive fjord system. My artist friend and wife Dragonfly Leathrum posted a wonderful travel essay with many photos that did not include these:

We were here to explore how the coastal ocean off Greenland may relate to Daugaard-Jensen Gletscher at the head of the fjord some 360 km away (195 nautical miles or about a day of constant steaming at 8 knots). This tidewater glacier discharges as much icy mass out to sea as does Petermann Gletscher or 79N Glacier to the north or half as much as Helheim, Kangerdlugssuaq, and Jacobshavn Glaciers to the south. Unlike all those other glaciers, Daugaard-Jensen and its fjord are still largely unexplored.

Location Map of Scoresby Sund. Kap Brewster is at bottom right while Daugaard-Jensen Gletscher 360 km away is near the top left.

Location Map of Scoresby Sund. Kap Brewster is at bottom right while Daugaard-Jensen Gletscher 360 km away is near the top left.

Part of the chart of the East Greenland coast drawn up by William Scoresby Jr. in 1822, showing the numerous features that he names in Liverpool land (Liverpool Coast) and adjacent areas. From: Scoresby (1823)

Part of the chart of the East Greenland coast drawn up by William Scoresby Jr. in 1822, showing the numerous features that he names in Liverpool land (Liverpool Coast) and adjacent areas. From: Scoresby (1823)

While the entrance between Kap Tobin and Kap Brewster was known to whalers in the early 19th century, it was William Scoresby Sr. after whom the fjord is named. His scientist son William Scoresby Jr. mapped coastal Greenland between 69.5 and 71.5 North latitude during his last voyage in 1822. Nobody entered the fjord until 1891 when Lt. Carl Ryder of the Danish Navy sailed deep into the fjord to explore the area for a year with 10 companions. They built a hut next to a natural port that they named Hekla Harbor. Amazingly, they also measured ocean temperature profiles almost every month from the surface to 400 m depth. I found these data at the National Ocean Data Center of the United States Government.

Ocean temperature (left panel) and salinity (right panel) as it varies with depth in different years. Blue represents measurements from 1891/92, red from 1990, and black from 2018.

Ocean temperature (left panel) and salinity (right panel) as it varies with depth in different years. Blue represents measurements from 1891/92, red from 1990, and black from 2018.

Searching for data from Scoresby Sund, I found 17 profiles of water temperature with data from at least 10 depths. Funny that 12 of these profiles were collected in 1891 and 1892 while the other 5 profile contain salinity measurements made in 1933, 1984, 1985, 1988, and 2002. The 1988 cast was taken by an Icelandic vessel and also contained continous data from a modern electronic sensor rather than waters collected by bottles. I “found” another 4 modern sensor profiles collected in 1990 at the Alfred-Wegener Institute in Germany.

That’s pretty much “it” … until we entered the fjord in 2018 when we collected another 27 casts thus more than doubling the ocean profiles. More exciting, though, is the very large shift in ocean temperatures from 1990 to 2018. The 1990 temperatures are very similar to the 1891/92 temperatures, but all old temperatures (also from 1933 and 1985, not shown) are all about 1 degree Celsius (2 degrees Fahrenheit) cooler than those we measured in 2018. Why is this so? Does such warming originate from outside the fjord? If so, how does the warmer Atlantic water at depth in deep water crosses the 80 km wide shallow continental shelf to enter Scoresby Sund? Are any of these ideas supported by actual data? What data are there?

Ocean data location off eastern Greenland collected from 1890 to 2010 that reside in NODC archives. Red are water bottle data while yellow are modern electronic sensor measurements. The white box bottom left is the entrance to Scoresby Sund. Light blue areas are water less than 500 m deep while dark blue shades are deeper than 1000 m.

Ocean data location off eastern Greenland collected from 1890 to 2010 that reside in NODC archives. Red are water bottle data while yellow are modern electronic sensor measurements. The white box bottom left is the entrance to Scoresby Sund. Light blue areas are water less than 500 m deep while dark blue shades are deeper than 1000 m.

Discoveries in science can be pretty basic, if one is at the right location at the right time with the right idea. Also, there is more data to the south that I did not yet look at to investigate the question of what causes the warming of bottom waters in Scoresby Sund.

EDIT Dec.-31, 2019: Replace “warmer” with “cooler” when comparing 1891 and 1990 (cooler) to 2018 (warmer) water temperatures.

Polar Bears and Guns and Politics

Polar bears are endangered and need protection. They hunt and eat meat to survive. Seals are such meat as are scientists walking and working on the sea ice. I am planing an experiment in polar bear habitat. Do I need a gun to protect myself and my students working with me? About 10 people told me “YES” last week, all with experience working in polar bear habitat. Who am I to say no? Encounters between bears and people happen, but only rarely. None of the 10 people advising me to carry a shotgun or rifle ever discharged their weapon or had a bear encounter.

Polar bear as seen in Kennedy Channel on Aug.-12, 2012. [Photo Credit: Kirk McNeil, Labrador from aboard the Canadian Coast Guard Ship Henry Larsen]

Polar bear as seen in Kennedy Channel on Aug.-12, 2012. [Photo Credit: Kirk McNeil, Labrador from aboard the Canadian Coast Guard Ship Henry Larsen]

In 3 month’s time I hope to do ~20 day trips from Thule Air Base near Pituffik, Greenland to explore the oceanography and acoustics of the local fjord covered by sea ice. The US National Science Foundation supports this work, maintains a dormitory where we sleep, and provides us with two snowmobiles. We will use these motorcycles on skies to reach science stations on the ice covering Wolstenholme Fjord. We will drill 10” holes through 3-5 feet of sea ice, set-up an electric winch connected to a small generator, and probe the ocean’s temperature, salinity, bottom depth, and ice thickness to prepare for a quiet acoustic communication system to move data under water from the outer fjord to the pier at Thule and the internet.

Thule-NSF2017

Leading this science effort, I will have to estimate and manage potential risks which include encounters with polar bears. I will have to decide how much money to allocate to each risk that then may not be available for other activities such as to support students, buy better sensors, or return in the summer. The first and almost always best response is to hire a local hunter who knows the area along with its bears, ice, and weather. There are about 600 people living in Qaanaaq about 100 miles to the north. Most of them are children and grand-children who were forcibly removed from Pituffik in 1952 when more than 13,000 Americans built a large air field during the height of the Cold War. The local llanguage spoken in remote Qaanaaq is the Inuktitut dialect of north-west Greenland, the first foreign language learnt in school is Danish, and English is not widely spoken, however, Qaanaaq has two non-Inuit villagers who originate from Denmark and Japan.

Relations between Qaanaaq and Thule Air Base are complex and sensitive with regard to politics and finances. One of many perspective is that of Kim Petersen who writes in Dissident Voice about “The Struggle against Colonialism and Imperialism in Kalaallit Nunaat.” Kalaallit Nunaat refers to Greenland in the local language. While the forced removal of native populations from Pituffik to Qaanaaq in 1952 and the crash of a nuclear armed B-52 bomber into Wolstenholme Fjord in 1968 are not in dispute, the political arguments presented seem to me rather narrow, one-dimensional, and rooted in a tired ideological Left-Wing mode of conspiracy-thinking. Does this perspective represent the community of Qaanaaq? Perhaps I need to ask someone who may know:

Working on the sea ice off northern Greenland [Photo credit, Steffen Olsen]

Working on the sea ice off northern Greenland [Photo credit, Steffen Olsen]

It is not straight-forward to bring a gun to Greenland as it requires a large amount of paper work. Another layer of regulations relates to bringing a gun to an US military installation. Shooting a polar bear is a burocratic and political nightmare, because strict quotas exist for the “taking” of polar bears. International complications include Canada, because the quotas are assigned to Canadian and Greenlandic hunters from the same bear population. It is a sensitive topic in many dimensions, a riddle for which I have no solution.

How much time do I spent to prepare for an unlikely event such as a fatal polar bear encounter? Could I not argue with ethics that were instilled into me when hiking in the back-country of Denali National Park (no guns there). Park rangers then told me that I enter bear habitat and should do so respectfully with minimal impact. They gave me useful pointers on how to lower contact and I saw no bears hiking for 4 days alone without a gun, but grizzlies eat berries while polar bears do not.

So, should I carry a gun, if I am not ready to kill a bear while working in bear country? I can accept the consequences of injury and death for myself, however, I cannot do so for those who are with me. Perhaps this then is a path to a solution: Discuss this with all who will be with me on the ice.