Glines Canyon Dam now invisible

In case you didn't notice the latest happenings on the Elwha River - the Glines Canyon Dam, while still a bit there, is now invisible. A blast a few days back (see John Gussman's footage of the blast here) took out the last remaining section of the dam visible to the web cam.

Before: Glines Canyon Dam Site on 26 January 2014

After: Glines Canyon Dam Site on 27 January 2014

The blast also lowered the river at the dam site, increasing the gradient of the river, and thereby increasing its erosive capacity. As a result there was an almost immediate uptick in turbidity downstream:

turbidity at the MacDonald Bridge gage on the Elwha River, 26-28 January 2014

Typically turbidity is closely linked to river flow, but in this case there was no increase in river flow - this turbidity was generated by the dam blast.

River discharge, MacDonald Bridge, 26-18 January 2014

A Tale of Two Decembers

An image stolen from Cliff Mass's blog post about Seattle's December 17, 2012 high water event

Do you remember last December? Likely you do, but perhaps not for the reason that I am thinking of. Last December (2012) was notable for the high water and coastal flooding that wet the shoreline of most of the Puget Sound region. That high water event was due to a convergence of really two factors - high astronomical tides (also known as "king" tides around these parts) and big "non-tidal residuals", or the component of water level that is not due to predictable tidal forces. Its worth noting that the non-tidal residual is really made up of a bunch of processes (that Cliff Mass describes here, I have described here, and others have described a bunch of places)...but for simplicity's sake I'm just going to treat collectively.

Water level data from Seattle from the December 17, 2012 high water event, which matched the previous record high water event from 1983. This plot includes the predicted water level (the blue line), the actual water level (the green line), and the difference between the two, which I term the "non-tidal residual" (the red line).

This December has been pretty mellow from a coastal flooding standpoint...so what is the difference? Last December the highest predicted tide during December in Seattle (as an example) was 3.91 m above MLLW, which is just about identical to this year's highest predicted high of 3.907 m above MLLW on Decmeber 6. Furthermore, the average predicted water level for December 2012 was 2.11 m above MLLW, while for 2013 it was the same. In other words, there is not a huge amount of difference in the astronomical tidal water level.

Seattle water levels for December 2012 (top) and December 2013 (bottom). The red line in each plot is the predicted water level, and the blue line is the actual water level.

The big difference between the two years was in the non-tidal residual, or the part of water level that is not predicted by the astronomical tide. In Puget Sound the non-tidal residual is most closely linked to atmospheric pressure, though it can also be due to other processes. Just a few days ago, for example, La Push, WA on the outer coast experienced large non-tidal residuals that were likely due primarily to wind piling water up against the coast.

The plots above, which show the predicted and actual water level from December 2012 and 2013 are sort of hard to interpret, so the plot below should help to clarify the different between the two months - this shows the difference between the predicted and actual water level for the two months:

So what should be clear is that in 2012 December water levels were much higher than those in December 2013, not due to "tides" (at least in the way that we usually think of them as being driven by astronomical forces), but rather due to very high average non-tidal residuals that lasted pretty much all month. In fact, the average of all measured water levels in December 2012 was 2.28 m above MLLW, while in December 2013 it was only 1.92 m above MLLW, a difference of over 14 inches. And when it comes to coastal flooding, 14 inches of water level makes a big difference...

In Memoriam: Maury Schwartz, Coastal Geologist

Dr. Maury Schwartz teaching a class...on the beach. Photographed by Hugh Shipman in 1991 or 1992

Dr. Maury Schwartz, eminent coastal geologist and Emeritus Faculty at Western Washington University, passed on a few days ago in Bellingham. When I started research work on the Elwha I was always distinctly aware of standing on Maury's broad intellectual shoulders; Maury spearheaded much of the early observational and descriptive work on Ediz Hook and the Elwha river delta, and also made significant contributions to the body of work that informs our conceptual models of the coastal geomorphological system at Elwha.

When I accepted a job with Washington Sea Grant in 2010 and started preparations for returning to Washington one of my fists tasks was to reach out to Maury via email. I was honored that he responded quickly and enthusiastically, and that initial email conversation led to an extended discussion via email and in person. As a relatively young entrant working in the field of coastal geology in Puget Sound, it was a huge honor to converse with Maury and trade ideas and debate the formation and evolution of our complex beaches, coastal spits and bluffs. I recall in particular meeting with Maury at a coffee shop in Bellingham, and leaving with a series of papers that Maury had brought for me along with a collection of napkins full of scribbles and notes on spit formation and development.

The last time I saw Maury was in the late summer of 2013, when Jim Johannessen brought Maury out to the Olympic Peninsula on what would be their final pilgrimage together to the beaches of the Elwha River delta. Jim and Maury had worked together in the 1990s and published one of the earliest, if not the earliest, comprehensive set of quantitative shoreline change analyses for the beaches adjacent to the Elwha River mouth. Maury was visibly weakened, but with our help was able to make his way across the logs and cobbles to lay eyes on the first of the sediment to reach the coast after the removal of the lower dam on the Elwha River. Maury's contributions to our understanding of the coastal landforms of Puget Sound were huge, and even during that final trip his passion for understanding their workings was clearly evident. To stand on the beach with him was an honor and an inspiration to try, in some small way, to continue his legacy.

Student research on Port Angeles Harbor

Students from my Introduction to Oceanography class deploy an oceanographic mooring off of the Port Angeles pier

My Peninsula College Introduction to Oceanography class just wrapped up for the quarter. This year, I tried a new thing (getting my students out on the water for a mini research cruise on the Olympic Coast National Marine Sanctuary's R/V Tatoosh), but also re-hashed an activity that was very successful last year: Building and deploying oceanographic moorings off of the Port Angeles pier. This year, though, I put more of an emphasis on analyzing the temperature and light data series that we collected between October and November.

The ingredients of a mooring

This is a tall order for students at the introductory level - I am asking them to create a hypothesis, plot these data and analyze them critically in order to try to ferret out patterns. But in the end I hope it is a valuable exercise and provides some insight into the process of science. Anyhow, I wanted to share one of this year's top papers, by Miranda Elsberry, who looked at the potential role that tides play in controlling the water temperature in the harbor. She does a nice job showing that in our data, there seems to be some relationship between the neap tide cycle and elevated water temperature in the harbo. Makes sense, right? We might assume that the residence time of water in the harbor goes up during the neap tide cycle, mixing is reduced, and temperature is thereby increased.

Introduction to Oceanography students building moorings

Anyhow,Here it is, in its entirety. Enjoy!

Tidal Water Levels and Bottom Water Temperature

For this final assignment I wanted to ask a question that I did not already know the answer to, I already knew the likely outcomes of questions like “Does Temperature vary with depth?” or “Does air temperature affect water temperature?” and so on. So I decided to explore the idea of tides. The question I had going into this assignment was: Does tidal water level affect the water temperature at the bottom of Station B? I chose to look at Station B because I thought that if the answer to my question was yes then it would be clearer at the medium depth of about 16 feet, rather than the deeper Station C or shallow station A. I did not choose to study Station A because of the possibility of the nearby creek changing the water temperature data.

Here are the stations referred to in her paper, for context

To see if there was a relation between water temperature and water level, I plotted the water temperature data collected by the Station B HOBO and the water level data that was provided in Canvas on the same chart. After plotting the data I looked for areas where the temperature and water level changed together.

Overall, I found that temperature did not clearly change with water level. However, even though the temperature line was clearly falling over time, there seemed to be a very slight change in the temperature plot where water level shows there was a neap tide cycle around the 16th and 28th of October. In my first plot (fig.1) I have circled the slight upwards bulges of the temperature line that occurred during the neap tide cycles.

Figure 1: Water Temperature at Bottom of Station B and Tidal Water Level Plot

I wondered if those slight changes were due to changes in air temperature instead of the tides. So I took the air temperature data that was provided in Canvas and plotted it on a chart with the bottom water temperature from Station B (fig. 2)

Figure 2: Air Temperature and Station B Bottom Water Temperature Plot

Other than the 5°F dip in air temperature and slight dip in bottom water temperature at the same time from around the 18th to the 23rd of October, the plot does not seem to show a very clear relationship between change in air and bottom water temperatures. So air temperature must not have caused the slight bulges in my first plot.

With plotting this data and examining it, I have found that there seems to be a connection between the water temperature at the bottom of Station B and the twice a month neap tide cycles. I do not know why neap tides would affect the temperature of water 16 feet below the surface, but there were very slight (by one degree) rise in temperature of the water when neap tides occurred. The change was very small, but it was visible on my chart, so it should be relevant. There are many other weather factors that I could explore that might have caused the temperature change, but air temperature did not seem to have caused it.

An On-the-water experience for Peninsula College Oceanography students

The Olympic Coast National Marine Sanctuary's R/V Tatoosh lands at Port Angeles harbor to offload a group of students from my Introduction to Oceanography course after a mini research cruise to a site on Port Angeles Harbor

I started teaching an Introduction to Oceanography class at Peninsula College last year, and have taken a keen interest in undergraduate education in STEM (science, technology, engineering and math). I've even gone so far as to get myself engaged with a nationwide project focused specifically on the question, "How do you go about doing ocean sciences education RIGHT at small community colleges?". Through that group I met Ardi Kveven, who runs the ORCA program at Everett Community College...and a few months back I went to visit her program in action. That experience motivated me to start talking to a variety of people who might help me provide my students with a true oceanographic field experience.

Rick Fletcher, OCNMS (with back to camera) and a student from Peninsula College prepare the Shipek sampler for deployment.

Those conversations yielded quick results: As a result of a very generous contribution of boat time on the Olympic Coast National Marine Sanctuary's R/V Tatoosh I was able to provide my Peninsula College Introduction to Oceanography class with an on-the-water experience. Yesterday, groups of students headed out to sites in Port Angeles Harbor to collect oceanographic data using a variety of tools and measurement techniques.

A group of students collects a water sample from a site near the Port Angeles wastewater outfall.

While the primary goal of this project was educational (in that it was intended to motivate students to pursue STEM fields), my hope is that we may be able to build a program that is able to sample sites in Port Angeles harbor repeatedly in the coming years. As a result sampling sites were set up in areas that may, in the years to come, change due to a variety of different environmental restorations either planned or in process. On Thursday, the class sampled sites that will be associated with the western harbor clean-up effort currently in the planning stages and a shoreline restoration on Ediz Hook, led by the Lower Elwha Klallam Tribe, that is currently underway.

Students process a sample and record data collected on a cruise on Port Angeles harbor.

In this way my hope is that, over time, the data collected by these students may start to contribute to our understanding of what successful environmental restoration in marine ecosystems looks like.

The R/V Tatoosh leaving the dock with a group of Peninsula College students on board

At each site we collected temperature, salinity and oxygen profiles using the OCNMS CTD. A sediment sample was collected using a Shipek grab, and then water samples were collected from the surface, and again at depth using a Niskin bottle. These samples were used to get independent measures of temperature and salinity (for the purposes of checking the data provided by the CTD), and we also measured pH in these samples with a hand-held electronic pH meter. Finally, a Secchi disk was used to estimate water clarity and light penetrations, and a plankton sample was collected.

A student processing the sediment sample from the Shipek grab.

Back at the dock we set up a sort of "lab":

Our lab...

...where, in addition to FREEZING (it was really cold) students tried to focus on sieving the sediment sample in order to collect and sort benthic invertebrates:

Students sieving a sediment sample

Benthic invertebrates from a site in the western harbor

A huge thank you to the Olympic Coast National Marine Sanctuary for making this happen, and particularly Rick Fletcher and Justin Ellis for operating R/V Tatoosh. Brad Stone from Peninsula College put in a huge effort on the boat to keep students on task. Also, Helle Andersen from the Feiro Marine Life Center worked on the dock, in the cold, to help students identify and understand their tiny invertebrates. Finally, numerous faculty at Peninsula College offered equipment, support and advice, but a particular thanks to Jack Ganzhorn, Brian Hague, and Barb Blackie.

Wandering HOBOs

I've said it before, and I will probably say it again: I am a fan of HOBOs. They are cheap and break-proof enough that I can use them with my Introduction to Oceanography Class, but also accurate and reliable enough that we use them routinely now in our efforts to understand the changing biological community around the mouth of the Elwha River. Most of these HOBOs have a pretty boring life - they get zip-tied to some fixed structure for days to months at a time, and sort of sit there doing their thing. In the video below, for example, you can see a few HOBOs attached to a "mooring" built and deployed by my Oceanography class in Port Angeles Harbor.

Occasionally, though, one goes rogue. And that was the case for the HOBO in the photo at top. This HOBO was found on August 7th, 2013 by Olympic Peninsula resident Vance Heydorn while beach-combing on the outside of Ediz Hook. Vance was kind enough to bring it to the Feiro Marine Life Center, which set off a round of serious head-scratching amongst a group of us that use these for research and education purposes. We all assumed that it was one of ours, lost from a mooring or mount somewhere in Port Angeles Harbor or the adjacent Strait of Juan de Fuca. We finally worked out that it definitely wasn't one of ours...which led me to contact the University of Washington's Friday Harbor Lab. It didn't take long to get word from one of their research teams that, indeed, this HOBO had been deployed in the intertidal zone at a site on the west side of San Juan Island on the 11th of July, and had gone missing at some point after that.

Temperature data recorded by the HOBO

Its sort of hard to figure out exactly when this HOBO broke free from its mount on San Juan Island, but based on the temperature record, I would guess that it was sometime between July 27 and 6 August. The 27th is when the big daily spikes in temperature, which are characteristic of the intertidal zone (which undergoes wide temperature swings in the summer as it is alternately exposed to warm air and cold water) go away...and on the other end we know it made it over here by the 7th of August. Either way you slice it, it was a fairly quick journey from the San Juan Islands (a straight line distance of about 45 km).

Map of the journey

The light intensity data recorded by the HOBO doesn't tell us a whole lot more...except that Vance stored it in a fairly dark spot before he brought it back to the Feiro Marine Life Center:

Light intensity data recorded by the HOBO

Tsunamis in the Strait of Juan de Fuca

A photo of probable "tsunami sands" in the Salt Creek salt marsh, Strait of Juan de Fuca. Photo by Sarah Sterling.

Its well known that what are called "far field" tsunamis impact the Strait of Juan de Fuca...heck, one of my early posts to this blog was of a tsunami wave propagating into Port Angeles Harbor after the Tohoku earthquake and tsunami that hit Japan in March 2011. And within the academic and emergency management community it is also well known that we are at risk from very large "near field" tsunamis - one generated near to our coast. In particular a so-called "mega-thrust" earthquake on the Cascadia subduction zone could generate a large and potentially catastrophic earthquake and tsunami that could impact much of the Pacific Northwest coast. The Washington Emergency Management Department, for example, is very focused on tsunami outreach and risk reduction throughout the coastal areas of Washington State.

However, since there hasn't been a large earthquake or tsunami in this part of the world since the "historic" period started its hard to really accept that we have a risk, especially in the relatively protected waters of the Strait of Juan de Fuca. Communities on the outer coast of Washington State seem to have embraced their risk, and are taking various steps to reduce that riks, either by building vertical evacuation structures, practicing evacuation drills, or even http://indiancountrytodaymedianetwork.com/article/quileute-is-moving-to-higher-ground-100321.

Increasingly, though, the traces of tsunamis that have impacted the shoreline of the Strait of Juan de Fuca are being uncovered. Today I learned of Ian Hutchinson, Curt Peterson and Sarah Sterling's latest paper, documenting their discovery of sand layers in the Salt Creek salt marsh, just west of Port Angeles. They detail the evidence that leads them to conclude that these sand layers were almost certainly deposited by tsunamis occurring 1000-2000 years ago (find the paper here, starting on page 12). This is added to some of the original work on the U.S. side of the Strait of Juan de Fuca that shows multiple tsunami sand beds in Discovery Bay, Curt Peterson's recently published work from Neah Bay, and tsunami sand beds documented on Whidbey Island. Taken together, it is clear that numerous sites on the Strait of Juan de Fuca appear to record repeated relatively large tsunamis.

What is at risk? Quite a bit, as documented here, and some communities are taking notice (see Clallam County's tsunami fact sheet and this story about the Lower Elwha Klallam Tribe's real evacuation after the Tohoku tsunami). Any time new information like Hutchinson et al, 2013 comes out, though, should be a moment that we reconsider our preparations, and redouble our efforts to plan and prepare.