What stands out is that Owen wasn’t simply a park ranger or scientist. He was someone who never stopped asking questions about Crater Lake, even decades after working there.Remembering Dr. F. Owen Hoffman
Park Ranger, Scientist, Researcher, and Friend of Crater LakeDr. F. Owen Hoffman spent the summers of 1966 through 1968 as a seasonal ranger-naturalist at Crater Lake National Park. Those three summers helped shape a lifelong fascination with one of America’s most extraordinary natural wonders.Owen was an accomplished runner at San Jose State College. In 1966, he reportedly ran up the steep Cleetwood Cove Trail in just 7½ minutes. He later recalled jogging the trail in his full wool ranger uniform after completing a day of boat tours.But Owen’s greatest contributions came through his scientific curiosity.While working at Crater Lake, he studied the movement of tiny aquatic organisms called zooplankton. His research led to a master’s degree in limnology and ecology from Oregon State University in 1969. He subsequently earned a doctorate and pursued a career as a nuclear scientist and consultant.Even after leaving the National Park Service, Crater Lake remained close to his heart.His contributions to understanding Crater Lake
Owen investigated some of the lake’s most fascinating mysteries.Why does Crater Lake rarely freeze? Owen explained that its enormous volume of water stores heat from the summer sun. Winter winds continually mix the lake, bringing relatively warmer water toward the surface. Only prolonged cold and calm conditions allow ice to form across the lake.How long did Crater Lake take to fill? In a 1999 article published in Crater Lake Nature Notes, Owen developed a mathematical model examining precipitation, evaporation, underground seepage, and ancient climate changes. He concluded that the lake’s development was considerably more complicated than earlier estimates suggested, with thousands of years required to reach its present condition.How deep is Crater Lake compared with other lakes? Owen carefully examined the difference between maximum depth and average depth. He argued that Crater Lake’s average depth of approximately 1,148 feet made it the deepest lake in North America by that measurement and among the deepest in the world.What is the history of the Old Man of the Lake? Owen explored possible explanations for the famous upright floating log. He suggested that changes in lake level might have contributed to its unusual history, while acknowledging that some questions about its origin remained unanswered.His memories of park life
Owen also preserved wonderful stories about working at Crater Lake during the 1960s.He remembered the evening ranger programs, the slide presentations at Crater Lake Lodge, and the high standards established by the park’s naturalist staff.He described the 1967 sinking of an old wooden research boat near Wizard Island, making room for Oregon State University’s Boston Whaler.He also recalled the dramatic June 1968 rescue of two young men stranded on a ledge above the lake. Owen and fellow researchers were involved in efforts to assist the rescue operation.These stories reveal another side of Owen: a man who valued his fellow rangers, remembered their adventures, and wanted their history preserved.A lifelong connection
Owen returned to Crater Lake as a volunteer in 1998, approximately 30 years after his final season as a ranger.He also served as a director of the Crater Lake Institute and continued corresponding with former rangers, researchers, and park historians.His writings show a man who cared deeply about scientific accuracy. When he believed a published figure was misleading, he explained why. When evidence was incomplete, he acknowledged the uncertainty. And when someone asked a question, he often responded with a thoughtful, detailed explanation.Owen Hoffman leaves a legacy of scientific inquiry, friendship, and dedication to Crater Lake National Park. His research helped explain the lake’s mysteries, while his memories helped preserve an important chapter of its history.One especially meaningful detail is that Owen’s correspondence includes exchanges with you and other former Crater Lake colleagues. These weren’t just scientific papers. They were memories shared among people who had experienced the park together.
Some of Owen’s Research
The Freezing of the Lake has more to do with stillness of the water, rather than extreme cold temperature.
By Dr. Owen Hoffman (former CRLA park ranger-naturalist and lake researcher (1966-68)
Actually, the reason why Crater Lake seldom ever freezes over is due to several factors, only one of which is its great depth. It has to do with physics.
As long as there is wind, the water of the Lake is mixed. Colder water at the Lake’s surface is continuously being replaced with somewhat warmer (4 degrees Celsius) from below. The annual heat budget for the Lake poured into the lake during annual solar irradiation is enormous.
Other factors to keep the Lake from freezing are:
(a) During the summer months there is a lack of cloud cover, allowing bright sunshine to input a tremendous amount of thermal energy, there is also a relative lack of wind during the cooler evenings;
(b) Daytime breezes keep the water in circulation, allowing the entire lake to store the summer solar input, with warmer surface temperatures occurring in the shallows and in late July and August;
(c) In winter, high winter winds keep the lake’s nearly constant 4 degree C waters in constant circulation, preventing the formation of a winter thermocline and keeping the temperature at the lake’s surface well above freezing.
For the lake to completely freeze over, a prolonged period of cold and calm is required to build a winter thermocline, which will eventually cause the water at the surface to reach zero degrees C. Once ice forms and completely covers the lake, the winter thermocline is protected from the mixing energy of the wind and the water temperature beneath the ice remains at zero degrees C.
However, for ice to last over a longer period of time, there also needs to be sufficient snow and cloud cover to prevent the winter sun from penetrating the otherwise transparent ice, warming the surface water and melting the ice from below.
August 1966 Record accent of Cleetwood Lake Trail by Ranger Owen Hoffman in 7.5 minutes. Owen was a champion runner from San Jose State and had his eye on an Olympic position. Eventually worked as a nuclear scientist and as a private consultant. His Crater Lake summers infused him with a life-long interest in the National Parks. The record run was preceded by many training accents during the summer. “As best as I can recall, this timed run to the top of the Cleetwood Trail was done in late July or early August. The stopwatch was mechanical and hand-held, meaning that the jarring of my arm swing could have affected the accuracy of the clock. But, I was in fine shape at the time, having just come off a competitive track season at San Jose State. For the hell of it, I would often jog the trail to the top in my full class ‘A’ woolen ranger uniform at the end of the day after having completed two boat tours (I don’t think we ever did as many as three tours in a day).” Owen January 1, 2010
Summer 1966 An email from Owen Hoffman, August 24, 2016 to the authors. – Prior to and including the summer of 1966, all evening NPS ranger-naturalist programs at Crater Lake were 2-man events, one ranger to be the MC to make announcements, sing campfire songs, and engage in crowd control, and the other ranger to concentrate solely on presenting the featured slide program.
There were two exceptions to the two-ranger approach to evening programs: (a) the primitive campfire program at Lost Creek, which was a one-ranger program, and (b) the evening slide program at Crater Lake Lodge.
At the Lodge, I too recall that park guests, visitors, and concession employees would sit on the stairs, and listen to the ranger slide presentation about the park. I still have fond memories of making those presentations, but I also remember being interrupted (albeit infrequently) by head-waiter announcements for guest seating in the dining room. We always carried a quarter in our wallets just in case the Kodak carousel tray jammed.
Each of us was responsible for our own material and presentation, but we were audited often. We felt a huge incentive to get better and better, with each presentation. Sometimes, the park superintendent, or his family, would attend our programs.
The very high standards expected of us were a product of the leadership of NPS Chief Naturalists, Bruce Black, Dick Brown, Bob Bruce…and of course the supervisory seasonal naturalist, Ted Arthur. And then there was the exceptional talent and leadership by example given by the excellent university professors on our seasonal staff, like Dr. Marion Jackson and Dr. Dwayne Curtis, as well as the numerous professional educators at the secondary and community college level, who were each polished public speakers. Owen
August 29 1967 The Park’s old wooden Ranger boat is sunk near Wizard Island, after using a sledgehammer to knock holes into the boat’s sides and bottom.
October 2010 – Owen Hoffman writes: Larry, That was the old Naturalist’s research boat that was owned by the NPS. In the summer of 1967, it was deemed unusable and beyond repair.
It was sunk to make room for the OSU Boston Whaler, which had been recently lowered into the lake by sliding it down over banks in late Spring of 1967, to use the NPS boat house on Wizard Island for winter shelter and storage.
The old Naturalist’s research boat was featured in the 1966 edition of “America’s Wonderlands” by National Geographic. It was photographed in the vicinity of the Phantom Ship with Bruce Black’s wife and daughters on board.
In 1967, our professor of limnology at OSU, Dr. Jack Donaldson, used the OSU Boston Whaler to tow the Naturalist’s research boat from its boathouse out into deeper waters where it was sunk. The boat was sunk by Park Ranger Larry Hakel. He used a sledge hammer to punch holes through the weakened hull of the boat. Doug Larson and I went along to watch and help as needed. Doug took photos.
The boat was last observed peacefully at rest on the lake floor by Mark Buktenica, who was inside the submersible Deep Rover. This happened sometime in 1988 or 1989.
Letter to the authors from Dr. Doug Larson, October 18, 2010
Hi Larry, Here are some photos that I took at Crater Lake in the summer of 1967. That summer, the Park Service decided to get rid of a boat that was stored on Wizard Island. Apparently the boat had been given to the Park Service years earlier to haul tourist around on Crater Lake. According to Dick Brown, Chief Park Naturalist, the boat had been used to smuggle alcoholic beverages from Cuba to Florida during the Prohibition Era. The boat was intercepted by the Coast Guard, confiscated, and later given to the Park Service.
Because of the unusually dry weather and high fire danger that summer, the Park Service ruled out burning the boat on Wizard Island. Instead, they decided to have it sunk in about 300 meters of water along a transect roughly halfway between Wizard Island and Crater Lake Lodge.
Photo 1 shows the boat parked on the shore of Wizard Island near the entrance of the shed where it had been stored, apparently for many years. Before the boat was towed out to the Lake, we filled the bottom with rocks.
Photos 2 shows us towing the boat toward its final resting place. The towboat is the OSU research vessel, a Boston Whaler powered by two 35 HP outboard motors. Owen Hoffman, grim-faced and wearing the red hardhat and orange sweatshirt, sits in the stern. Jack Donaldson, barely visible and wearing a plaid shirt, far left, operates the research Rod Cranson’s head, inside of the tan-colored hard had, appears in the lower right-hand corner of the photo.
Photo 3 shows the crew preparing the boat for sinking. Note that the engine, a 12 or 16-cylinder job, has been left in the boat to help keep it submerged on the Lake bottom. Four people are shown in this photo. The person nearest the camera and wearing a tan hardhat and olive-green shirt is Naturalist Ted Aurther. Next to him, with his back to the camera and wearing a red hard hat, is a Park Service employee, Larry Hakel. The third person, wearing a red hardhat and orange sweatshirt is Owen Hoffman. The fourth person, whose straw hat is the only thing showing, is Jack Donaldson. Both Hoffman and Donaldson are leaning well into the boat.
Photo 4 shows four or our crew making final preparations for sinking. The person wearing the tan-colored hardhat and blue sweatshirt is Rod Cranson. Own Hoffman, red hardhat and orange sweatshirt, holds the rope tethered to the tourist boat. Jack Donaldson, straw hat and plaid shirt, watches Larry, wearing no hat, preparing to perforate the tourist boat’s hull with a sledgehammer.
Photo 5; Holes appear in the tourist boat’s hull as Larry swings his hammer. Rod Cranson captures this destruction with his camera. Photos 6,7 and 8 show the boat steadily sinking. I show these last three photos when I give talks about our research at Crater Lake. I say that there are days for limnologists on the lake when everything seems to go wrong. . Best regards, Doug.
In a message dated 11/6/2007 12:28:01 P.M. Eastern Standard Time,
I was on that boat with you and Dave Lange.
And I’m the one who first talked Dave into getting a seasonal job with the NPS. We both attended SJS, had many of the same professors, and he heard me talk at San Jose State about the great time I had during my first season at the park when I reported back during the fall semester of 1966. I’ve lost track of him, but last saw him and his wife when we invited them out for dinner in Whitefish, MT outside of Glacier NP in 1998. Our trip to Glacier NP occurred after my first week VIPing for Steve Mark and Marsha McCabe at CRLA. Dave became very good friends with Dan Sholly. Owen Hoffman
From: franksooth@comcast.net [mailto:franksooth@comcast.net]
Sent: Tuesday, November 06, 2007
To: Pkrnger@aol.com
Subject: Re: Rescue June 18, 1968
Hi Owen: I remember this incident of the guys stuck on a ledge. I vaguely recall someone saying later that they had not been “stuck,” but rather wanted to experience the thrill of being rescued, possibly by helicopter. I believe they were heavily fined for rescue costs…several thousand dollars. Both were Minnesota college students. I remember hauling the six or seven-member rescue team and their equipment from Cleetwood Cove to the wall below the ledge in the Whaler, a distance of 2-3 miles perhaps. Jack was running the boat. We were huddled behind, sitting on equipment boxes.
I too worried about sinking as we crossed the lake. Looking at my old Crater Lake data sheets, the lake’s surface temperature on June 14, 1968 was 6.8 degrees C (44 degrees F), certainly quite chilly for a nighttime swim back to Cleetwood. We were fortunate that the wind didn’t pick up and produce some sizeable waves…we would have been swamped…. and sunk. It was getting dark when we returned to Cleetwood with the rescue party, and if my memory serves me well, it was pitch black going up the trail to the rim.
The helicopter dropped food and sleeping bags to the two guys that evening, then rescued them the next morning. As the helicopter was landing near the lodge–with one of the rescued guys suspended in a harness underneath–its twin rotors produced a tornado of dust. People waiting near the helicopter-landing zone scrambled but still got covered with swirling dirt and debris. Quite a sight. Unfortunately, I didn’t have my camera with me. Best regards, Doug LarsonFrom: Pkrnger@aol.com
To: Lloyd Smith,
If you remember, it was my research boat you refer to. Or, at least the research boat from OSU. It was a Boston whaler. Dr. Jack Donaldson was on the lake that day, with Doug Larson and myself. We had spent the night on the lake sampling for zooplankton, but had attempted to assist this rescue. Our efforts were called off due to the difficulty of terrain in getting materials up to the boys, although Jack wanted to try a solo attempt. I think Larry Hakel made the final decision to not proceed. (Actually it was Chief Ranger Buck Evens.) OwenFrom: “James S. Rouse” <jsrouse@fidalgo.net>
Date: Mon, 26 May 2008
To: Owen Hoffman <Pkrnger@aol.com>
“Why Is Crater Lake So Blue?” – a novel about the 1975 Crater Lake water crisis, by Michael LaLumiere
Yes Owen, I do have the book. Ron had sent it to me some time ago. (Thanks again Ron).
As you may know, I was in the Regional Office, as Chief of Wilderness/Environmental Compliance, etc. I was following the situation close and offering some technical counsel. The book refers to the office in Klamath Falls as a Regional Office, which of course it wasn’t, and it tended to minimize the role of that Group Office. We called on Jeff Adams quite a bit during that concern. (I have to keep in mind that the book is a novel, and not a historical report.)
Owen: I also agree with you that the dorm is an eyesore from the Garfield trail, and perhaps yet some-thing can be done to mitigate that, like some landscaping work. You must also realize the tough spot the Reg. Dir. was in at that time. Seasonal quarters for employees were desperately needed for fire and safety concerns in the upper levels of that Lodge. The planning and design work for that dorm was done by the WODC (Western Office of Design & Construction in San Francisco.) This was before NEPA was enacted; therefore no extent of public involvement took place. You also are aware that there was considerable protest by some of the Conc. employees of this action. Well the project was funded and construction got underway, and of course the health dilemma didn’t crop up until a year later.
As far as a cover-up as the book alleges. There was no gag order in place. However the decision to close a Park is extremely serious with all kinds of ramifications. Thank goodness we had the Public Health Service and Corps of Engineers for back up on that decision.
Perhaps there were some service-wide lessons learned of this tragic incident, especially in the construction of sewer and water lines.
I have rambled enough on this subject, but thought you might be interested in my perspective. Jim Rouse
P.S. Former CRLA Superintendent, Dick Sims came to the Regional Office and worked for me in Environmental Compliance after the water crisis. Then after I was at CRLA a while, Ernie Borgman retired from the K. Falls office, so I ran both of those places.October 1 1983 According to USGS records Crater Lake reached its maximum water level at 6175.91 feet above sea level. “Crater Lake’s maximum known elevation is 6,180.5 feet, the average of several observations of lichens made between 1916 and 1960.” Source unknown. Very interesting too, that there is one point on the graph that is just about at 6180 feet. That point is reported for 1914. I would surmise that that was an actual historic surface elevation measurement, rather than an estimate made from measuring the density of lichen on near-shoreline rocks? (Owen Hoffman, 2016)
Thanks Ron for forwarding to me this interesting article. The absence of lichen at a slightly higher level than the reported maximum surface elevation indicates that the lake was once likely higher elevation than the maximum observed, but that this maximum occurred in the not too distant past; however, at a time prior to the reporting of measurements of the lake’s surface elevation.
Note that the observed maximum elevation for the lake’s surface of 6179.34 feet, reported for March 25, 1975, is the likely basis for the USGS benchmark for the surface of 1883 meters, as reported on the USGS topographical maps and in Bacon et al. (2002). This, the USGS benchmark for the lake’s surface elevation of 1883 m, is what the USGS uses to compute the lake’s maximum and average depth of Crater Lake of 594 ± 2m, and 350m ± 1 m, respectively, (equivalent to 1949 ± 6.6 feet, and 1148 ± 3.3 feet, respectively).
Interestingly, the NPS in its various reports indeed gives the lake’s average depth as 350 meters, but consistently refers to the reported maximum depth as 1943 feet (592 meters) in all it’s brochures and in most online sources. I would like to point out, as I’ve tried to do in the past, that it’s not quite correct for the lake’s average depth to be listed as 350 meters and yet have the estimate of the maximum depth reported as markedly less than 594 meters, even though the difference between these two estimates of maximum depth may not be statistically significant due to the errors of the USGS soundings of the summer of 2000.
Perhaps the need to update the NPS published estimates of the maximum depth of the lake to 594 meters isn’t being done by the NPS because of the cost of reprinting brochures, etc.?
Thanks again for sharing this article with me.
Owen
F. Owen Hoffman, Ph. D., former lake researcher at CRLA
106 Parma Rd.
Oak Ridge, TN 37830
Looking at the Average Depths of Crater Lake
By Dr. Owen Hoffman
Over time, snowmelt and rain collected in the crater to form the lake, which at 1949 feet deep, is presently the deepest in the USA, 2nd in North America, and 9th in the world. Based on a comparison of average depths, however, Crater Lake at 1148 feet, is the deepest in the Western Hemisphere and third deepest in the world.
On average, Crater Lake is the deepest lake in North American and third in the world.
The 50 meter for water transparency of Lake Baikal is a likely gross exaggeration. The deepest secchi disk reading at Crater Lake in Oregon is a little over 40 meters, and that estimate was determined using an oversized device.
Lake Baikal is the largest and deepest of the world’s lakes. It’s also the oldest geologically. The fact that Lake Baikal has an endemic population of fresh water seals is new news for me, and this fact is indeed fascinating.
However, based on a comparison of average depths, Crater Lake is on average the deepest lake in the world, among all lakes whose basins are above sea level. Lake Baikal and Lake Tanganyika are far deeper than Crater Lake on all counts, comparing either maximum depths or average depths, but both have basins that are below sea level.At least a thousand years to fill: may have taken 200 years for the caldera floor to cool sufficiently to hold water; so, between 1000 & 1500 yrs. So, the lake was nearly full as recently as 6000 to 6500 years ago. oldest water in the Lake estimated to be approximately 1500 years old ! (remember, Xerothermic climate was warmer, dryer during this episode).
“One of the biggest needs to be answered is: how long did it take to fill the Lake and how long has it been in its present condition and elevation.”
————————————————-Volume XXX – 1999
Crater Lake Nature Notes
The Filling of Crater Lake By F. Owen Hoffman, PhD.
It was 30 years ago last summer since I last worked at Crater Lake. From 1966 to 1968 I was a seasonal park naturalist and during that time I conducted research on the vertical migrations of zooplankton in the lake. This research led to a master’s degree in limnology and ecology from Oregon State University in 1969. Last August I volunteered for one week as a way to reacquaint myself with the park. I soon realized that I had forgotten many facts and quite a few had been revised since my last time in uniform. This dictated a visit to the park library.
One of the intriguing questions I came across in my brief survey of park-specific literature was: how quickly did the lake form, or how many years did it take to reach the present water level? I looked in the library, but found little or no information about what might seem to be a worthy focus of scientific investigation. The best thing I found was a paper published in 1994, where the authors claim that Crater Lake reached its current level in only 300 years (Nelson, et al. 1994). Being curious, and traveling with my laptop computer, I began to develop a simple mathematical model of the lake aimed at obtaining the answer (if only in an approximate way) to this question.
Methods
My mathematical model was initially constructed on the basic assumption that the hydrological processes of the past are not dramatically dissimilar to those of the present. For starters, I assumed:
(a) annual precipitation of 30.4 billion gallons (Phillips and VanDenburgh 1968);
(b) annual average evaporation of 15.2 billion gallons, based on an estimated evaporation rate of 120 cm per year (Redmond 1990);
(c) subsurface seepage that depends on the amount of water in the lake at any time.For my initial calculations, I set seepage at 0.33 percent of the lake’s volume per year (as derived from a net annual input of 15.2 billion gallons divided by the lake volume of 4.6 trillion gallons). Since evaporation will change somewhat with lake depth, I added an adjustment factor to account for the increase in surface area occurring as the lake filled to its present depth. I included an additional adjustment to the seepage rate to simulate more seepage with increasing depth as the lake filled. This adjustment accounts for both increased pressure from a rising lake level and increased bottom surface area. In the beginning, when there were only 230 billion gallons of water (assumed to have accumulated from ground water and hydrothermal sources), seepage is therefore estimated at 0.03 percent of lake volume. Conversely, when the lake became half full, seepage was about 0.2 percent of lake volume.
The model is based on values for present conditions, but this cannot be assumed over the entire period of lake formation. Analysis of the lake sediment and samples of pollen indicate that, at least initially, the climate was not unlike today (Nelson et al., 1994). It is thought that Wizard Island formed not too long after the collapse of Mount Mazama and that the lake was within 250 feet of its current level at that time, Consequently, I assume that conditions of precipitation and temperature similar to the present day, existed for roughly 400 to 500 years after Mazama’s collapse. Soon afterwards, however, a warmer and drier period commenced and lasted as long as 1,000 years. This drier period affected the entire region of the Pacific Northwest. Exactly how dry was it? No one really knows for sure, but to simulate this effect I reduced precipitation during this time period to between 30 and 50 percent of present day averages while also increasing evaporation by 10 to 20 percent.
To simulate the filling of Crater Lake, I used the software package STELLA II which has been specifically designed for the development of models for time dependent phenomena. This software is ideal for examining the effect of different assumptions about climate on the formation of Crater Lake.
Results
Crater Lake was formed in the collapsed caldera of Mount Mazama. Its formation began soon after the collapse, almost as quickly as the caldera floor cooled to the point where water could accumulate on the bottom, The evidence to date suggests that the young lake probably resulted from ground water draining back into the caldera from the surrounding slopes and hydrothermal springs. Since annual precipitation did not vary substantially from that of the present climatic regime, the lake rapidly (in geological terms) increased in depth–gaining much more than the present net input of 15.2 billion gallons of water per year. The actual gain would depend upon the amount of evaporation, relative to the increase in surface of the lake, with early seepage having a negligible contribution to the annual loss.
Based on these assumptions, Crater Lake probably reached about half of its present size within 150 years (Fig. 1), rising at a rate of some three to four feet per year. After roughly 300 years, the lake would have reached the level that was present at the time of Wizard Island’s formation. This also means that at 400 years since the collapse of Mount Mazama, Crater Lake reached about 90 percent of its present volume.
Approximately 500 years after the collapse, a 1,000-year period of drier climate ensued. This caused the lake surface to fall steadily and by the time this “altithermal” or “xeric” period gave way to cooler and more humid conditions (not unlike the present time), the lake could have lost between 40 and 80 percent of the peak volume reached at the onset of the dry period. As precipitation increased, the lake once again started to rise and reached 95 percent of present day volume about 2,000 years after Mount Mazama collapsed. The final stage of filling Crater Lake took another 500 years and required conditions that produced a relative equilibrium among precipitation, seepage, and evaporation. Because of the changes in climate, complete equilibrium among precipitation, evaporation, and seepage did not occur for another 1,500 to 2,000 years thereafter. In other words, it took about 2,200 to perhaps more than 3,000 years for the lake to reach the present state of complete equilibrium with an average depth of 1,066 feet (325 m) and a maximum depth of 1932 feet (589 in). If it were not for the 1,000-year dry period, Crater Lake would have reached its present level between 1,100 and 1,500 years after Mount Mazama’s collapse 7,700 years ago. Due to the 1,000-year dry period, evaporation and seepage exceeded precipitation and the lake fell to more than half its present level (Fig. 1). During this dry millennium it is likely that the lake water would also have been richer in minerals, more biologically productive, and thus less transparent than it is at present.
Crater Lake in the Future
Is the lake always going to stay like it is today? Given enough time, most certainly not. Perhaps the most imminent change, however, will be that of climate and its effect on precipitation. Any change in annual precipitation will have a direct effect on the level of Crater Lake. If precipitation begins to decline as climate changes to a drier condition, evaporation and seepage will again exceed precipitation so the lake level will drop. If precipitation increases, the lake level should rise and perhaps find a new equilibrium. There is no evidence to date that Crater Lake ever reached levels substantially above present. Nevertheless, such changes may occur over the next century or so. Over the next few thousand years, however, pronounced climate changes are certainly anticipated and with these changes will come fluctuations in lake levels, If we project ahead even further in time to, say, one million years or more, then it is likely that renewed volcanic activity or some other process of mountain building will occur, These major processes will dramatically change the appearance and structure of Crater Lake as we now know it. Few lakes on Earth have had a life-span that transcends a million years.References
C.H. Nelson, et al., “The volcanic, sedimentologic, and paleolimnologic history of the Crater Lake caldera floor, Oregon: Evidence for small caldera evolution,” Geological Society of America Bulletin 106 (May 1994), pp. 684-704.
K.N. Phillips and A.S. VanDenburgh, Hydrology of Crater, East, and Davis Lakes, Oregon. USGS Water Supply Paper 1859-E. Washington, D.C.: Government Printing Office, 1968.
K.T. Redmond, “Crater Lake climate and lake level variability,” pp. 127-141 in E.T. Drake, et al (eds.), Crater Lake: An Ecosystem Study. San Francisco: Pacific Division, American Association for the Advancement of Science, 1990.June 7, 2005 (MT)
Since you asked Glad that’s cleared up
I just read your reference to my 1999 Crater Lake Nature Note on the filling of Crater Lake, in which you quote the time of the lake’s filling to be 300 years. Thank you for mentioning my Nature Note article as a reference source of information on the filling of the lake.
Careful reading of my article would reveal that it probably took much more than 1,000 years to fill the lake. The 300-year estimate is only plausible by assuming present-day precipitation rates and no substantial subsurface seepage until the lake reached its present-day level (an assumption that some have made, but not totally convincing to me).
Once seepage occurs, the rate of filling of Crater Lake slows down considerably, especially during the final 10 percent of reaching the present level. The longer time for filling of Crater Lake includes the fact that the precipitation rate hasn’t always been the same as that of today.
Sincerely, F. Owen Hoffman, Ph. D. Oak Ridge, Tenn.
Thanks for clarifying that, Owen. We’re glad you did the math and not us. We’re still recovering from the math a reader asked of us to find out how long it would take Medford to drain the lake for municipal water, an unlikely scenario considering the lake is part of a national park.
Incidentally, we had one reader try to stump us further by asking how long it would take a snowflake that landed on the outer rim of Crater Lake to make it to the ocean. That’s easy! The snowflake would melt LONG before it got close to the ocean, so the answer to that trick question is “never.” We sure dodged a bullet on that one.
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On Tue, Oct 11, 2016 at 10:43 AM, Owen Hoffman ?<pkrnger@aol.com> wrote:
From 1967-1968, as part of my duties as a seasonal park ranger-naturalist at Crater Lake, I was given special project time to engage in limnological research. I used this research to support my MS thesis (obtained from Oregon State University in 1969).
As the recently posted article on the Old Man of the Lake reports, its origin is still a much of a mystery. The long-standing explanation is that the Old Man, a mountain hemlock, fell into the lake with a rock slide. Supposedly, it had rocks embedded in it’s roots to cause the Old Man to float vertically. When this actually occurred is unknown. But, from the earliest time of recorded observations, perhaps as early as 1902, there were no intact roots visible in the lower portion of the stump and no rocks embedded in those non-existent roots. Yet, the stump still floats vertically throughout the lake.
One idea several of us have batted around from time to time in our attempt to explain the origin of the Old Man of the Lake, which is not mentioned in the posted article, is whether or not it could be plausible that this mountain hemlock once grew on or near the shoreline of the lake during a time, much more than a century ago, when the lake’s surface was somewhat lower than at present (due to a prolonged period of lower than average annual precipitation). As the climate became more moist and annual precipitation increased, the lake’s surface rose and approached its current level.
The roots of the tree quickly drowned as the lower portions of the trunk became water-logged and the tree quickly died, shedding it’s upper branches and needles. Eventually, the roots of the stump decayed below the water and the submerged soil surface, and the partially water-logged stump eventually floated up vertically, with the upper portions of the stump being much less dense than the lower water logged portions. As reported, the Old Man continues floating around the lake to this very day.
The cold pelagic oligotrophic waters of the lake have prevented further decay of the stump, and I believe the stump is essentially in virtually the same condition as it was 50 years ago. However, standing or sitting on the top of the stump is no longer permitted by the NPS (which is a good thing). Owen
On Oct 18, 2016, at 5:16 AM, Buktenica, Mark <mark_buktenica@nps.gov> wrote:
HI Owen,
Thanks for the reply.
One thing that has “stumped” me: Where does the notion the the old man is a hemlock come from? I don’t see where that was determined by anyone.
Any ideas – did I read over that fact somewhere?
Mark
October 11, 2016 – Written by Dr. Owen Hoffman – I recall being told that it was a mountain hemlock by my mentors and supervisors, Richard McPike Brown and Glen Kaye in 1966. At that time, Dr. Marion Jackson and Adolf Faller were conducting the ecological survey of the flora of Wizard Island, documenting each species of plant form found within a few meters either side of several transects run from top of the island to shoreline. Dick Brown was also a trained botanist. Since then, I have always assumed that what I was told, was a fact.
But, given the size of the stump, and the abundance of mountain hemlocks growing on the highly unstable north-facing slopes of the south caldera wall, what else is it likely to be? Shasta red fir? Engleman spruce? Whitebark pine? Ponderosa pine? Lodgepole pine? Of course, many decades have passed since I recall being told that it was a mountain hemlock, and memory can be amazingly fickle, mine included.
I’d be very interested if there have been any more definitive determinations of the species of the Old Man.
It’s great to hear from you.
Owen
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Dr. F. Owen Hoffman spent the summers of 1966 through 1968 as a seasonal naturalist at Crater Lake. He volunteered at the park in 1998.
Among the named lakes of the world, Crater Lake is the 8th, not the 7th deepest. The reason is the recent discovery of subglacial Lake Vostok in Antartica. Lake Vostok has been found to have a maximum depth of as much as 1000 meters, much larger than Crater Lake’s maximum depth of 594 meters. Of course, if we declare that Lake Vostok is a “special case,” due to the fact that it resides under 13,000 feet of Antarctic ice, then indeed the citation of Crater Lake as the world’s 7th deepest lake is correct when compared with other lakes whose surface is free of ice at least for part of the year, and based on the comparison of officially reported maximum depths for the lakes of the world.
However, if the average depth of Crater Lake is compared with the average depth of other “deepest lakes”, which includes the average depth of subglacial Lake Vostok, Crater Lake becomes the third deepest in the world and the deepest in North America. Crater Lake is also by far the smallest of the world’s deepest lakes. It is the smallest among these lakes both in surface area and by volume, a testimony to the unique manner in which it was formed. In fact, Crater Lake is so small that it is the only one of the world’s deepest lakes whose opposite shores are visible to an observer, regardless of where one is located.
The officially documented maximum and average depths of Crater Lake can be obtained from the attached open literature publications, produced by USGS scientists (Bacon et al., 2002, and Nathenson et al., 2007
Note that the volume of water in Crater Lake is a simple product of it’s average depth (350 meters) and its surface area (53.4 sq. km). Thus, 0.35 km X 53.4 = 18.7 cubic km.======================
Crater Lake, On Average, Is Deepest Lake in North America
Crater Lake’s ranking as one of the world’s deepest lakes varies by how list is determined
By Lee Juillerat H&N Regional Editor
Thursday, November 29, 2007 12:01 AM PST
Is Crater Lake the seventh deepest lake in the world, the eighth or the third?
Depends on how it’s figured.
Owen Hoffman, a director with the Crater Lake Institute and a former park ranger, created a series of scenarios that give argument to any of the three claims.
Typically, Crater Lake is regarded the world’s seventh deepest lake, and the deepest in the U.S., with a maximum depth of 1,949 feet.
Hoffman, whose research at the park from 1966 to 1968 led to a master’s degree in limnology and ecology from Oregon State University, said Crater Lake could be regarded the world’s eighth deepest lake with the recent discovery of sub-glacial Lake Vostok in Antarctica, which is believed to be 2,133 feet deep. The lake surface of Vostok, however, is covered by nearly 13,000 feet of ice that, based on studies, is almost as old as the oldest rocks inside the Crater Lake caldera.
But using other criteria, Hoffman says Crater Lake can be regarded the deepest lake in North America, and third deepest in the world.
Hoffman’s revised ranking is based on determining an average depth.
Great Slave Lake in Canada, with a maximum depth of 2,014 feet, or 614 meters, is the deepest in North America. Great Slave, however, has an average depth of only 73 meters. Crater Lake, created by a series of eruptions that blew off the top of prehistoric Mount Mazama 7,700 years ago leaving the caldera that contains the lake, has an average depth of 1,148 feet, or 349 meters.
Based on Hoffman’s research, the deepest lake in the world, Baikal in Russia, has a maximum depth of 1,637 meters and average depth of 758 meters. The second deepest lake, Tanganyika, has a maximum depth of 1,470 meters and an average depth of 540 meters, which means it retains second place.
“Compared to the average depth of Crater Lake, the other lakes begin to fall behind,” Hoffman said, noting the Caspian Sea, which has a maximum depth of 1,025 meters, has an average depth of 184 meters.
Likewise, Lake Vostok, with its maximum depth of about 1,000 meters, or 2,133 feet, has an average depth of 292 meters, while Lake Issyk-Kul, with a maximum depth of 668 meters, has an average depth of 270 meters. The average depth of Lake Tahoe, which has a maximum depth of 501 meters, is 305 meters.
“Thus,” Hoffman said, “based on its average depth Crater Lake has moved up among the lakes of the world from eighth place — seventh if one excludes the subglacial Lake Vostok — to win the bronze medal.”=================
Crater lake is deep, but where does it rank?
December 2, 2007 Associated Press
Depending on how you figure it, Crater Lake the eighth, seventh or third-deepest lake in the world.
Owen Hoffman, a director with the Crater Lake Institute and a former park ranger, says different scenarios based on average depth and other factors can back any of those claims.
Typically, Crater Lake ranks seventh and is the deepest in the nation at 1,949 feet.
Hoffman said Crater Lake could rank eighth in the world with the recent discovery of sub-glacial Lake Vostok in Antarctica, believed to be 2,133 feet deep.
But Vostok is covered by nearly 13,000 feet of ice that appears to be eons old.
By other standards, Hoffman says, Crater Lake could rank third in the world.
Hoffman’s revised ranking is based on determining an average depth. Great Slave Lake in Canada, at 2,014 feet, is the deepest in North America. Great Slave, however, has an average depth of only abut 226 feet based on surface area.
Crater Lake, created by eruptions of Mount Mazama 7,700 years ago, has an average depth of 1,148 feet. Based on Hoffman’s research, the deepest lake in the world, Baikal in Russia, has a maximum depth of 5,070 feet and an average depth of 2,350 feet.
The second deepest lake, Tanganyika, in Africa, has a maximum depth of about 4,550 feet and an average of 1,675 feet.
But after Crater Lake others fall behind.
Thus, Hoffman said, based on its average depth, Crater Lake is in third place if one excludes the subglacial Lake Vostok.
Different scientists sometimes calculate differing depths for lakes.
Based on water volume, Crater Lake falls far behind other challengers because of its compact size. But Hoffman said it is the only one of the lakes in the race managed completely as a national park.
He said Crater Lake has another unusual claim: It is one of two contenders without an incoming or out flowing stream.
The other is Vostok, under more than two miles of Arctic ice.===========================
Originally barren
