Tuesday, October 24, 2017

Sea Level Rise in the news

A history of long-term relative sea level change in Friday Harbor, Washington - a pattern that our data suggest is not due to land level change...but rather to the sea rising
Is it just me, or is sea level rise breaking through in our neck of the woods?  This week there were multiple articles making the rounds focused on sea level rise in Washington State including
reporting at the Seattle Times and KIRO7 on Zillow's updated sea level rise vulnerability assessment for real estate (which I will get to later) and Chris Dunagan's reporting for the Encyclopedia of Puget Sound on issues surrounding homeowner decision-making in the era of sea level rise and also his piece on SLR planning on Washington State.

Nuisance flooding like this, in Port Townsend on 10 March 2016, is almost certain to become more common and more of a problem in the future.  Photo courtesy of the Local 20/20 King Tides Team
The concept of climate-driven sea level change is nothing new...its been part of the climate change conversation for decades.  What is evolving is our understanding of the processes that drive sea level change (typically referred to as sea level components) over the community planning time-frames of interest.  The Earth system is complex, though, and the problem of interest here is complicated and multi-part:  How do emissions of greenhouse gases integrate with the natural cycles of those gases, how do the resulting concentrations influence the global heat budget, then how is extra heat distributed around and through the globe, and (finally) what are the process and rates at which that heat starts affect the components that lead to sea level rise (for example, how does that head lead to the break down of large masses of land-grounded ice on Antarctica)? 

Antarctica - a huge mass of land-grounded ice (this is an artists rendering of a cut-away view through the ice).  Its future matters to us.  Photo credit:  National Geographic
The evolving understanding of the processes that drive sea level change has led to an intense focus on this problem amongst the scientific community, as evidenced by the publication rate of papers focusing on sea level rise.  I used Web of Science to search for papers with the topics "sea level rise" and "climate change" and came up with this publication distribution through time:


This intense focus on the processes that drive sea level rise, of course, has led to a community planning problem, though; projections of sea level rise, or how much we can expect, change through time.  This isn't surprising if you think about it.  Projecting anything is hard.  As a society we make projections all the time in any number of fields...and many of them don't play out as expected.  In the case of sea level rise, projections will change as our understanding of processes driving sea level rise evolves, and also as we observe sea level rise happening and can compare those observations against projections.

This brings me back around to Zillow's analysis.  I like this approach that they took, where they used their national scope and data-analytics expertise to look at the possible national implications of sea level rise on their core product - homes.  Using a sea level rise of six feet relative to present, they found (perhaps not surprisingly) that places like Florida have a lot at stake.  It also is a reminder, though, that Washington State is not immune from sea level rise (even though we may be less vulnerable on a national scale) - there is a lot of high value infrastructure exposed.

Zillow has taken some criticism though, for the particular sea level they chose to do their analysis with - six feet relative to present sea level.  The Washington Policy Center published a blog, for example, saying that six feet was out of alignment with the most recently published projections by the IPCC.  An early statement in the article sets the tone, "Their projections are, essentially, made up".

Is six feet of sea level rise made up?  Does it "ignore the science", as the title of the Washington Policy Center piece implies?  No, quite the opposite, and here we simply see this problem associated with a rapidly advancing scientific endeavor.  The Zillow analysis uses a very recent NOAA assessment that attempts to assess the likelihood of different levels of sea level rise across the full range of uncertainty (using a very similar approach to what we are doing with the Washington Coastal Resilience Project).  By contrast, the IPCC projection plot shown in the Washington Policy Center blog only communicates a narrower "likely range", which the Washington Policy Center's blog misinterprets as communicating full range of uncertainty.  Zillow nicely acknowledges the uncertainty that the NOAA assessment is trying to communicate by stating, "if the oceans rise six feet – roughly midway between the high end of what the government says is “very likely” (4.3 feet) and the possibility of an 8-foot or greater rise that cannot be excluded." 

Lets dive a bit deeper here.  The "upper ends" of the probability distribution, where sea level rise exceeds the ~2-3 ft (by 2100) best estimate, are driven by places like Antarctica melting a lot more than was previously assumed in past sea level rise projections (ice sheet uncertainties, and their implications, are also touched on in this fascinating recent article by Forbes).  Science seems to be pointing towards these large masses of ice being more sensitive to climate change than has been previously assumed - a conclusion that, if it holds up, will lead to a greater likelihood of higer sea levels represented in future projections.  Its also worth acknowledging that, while 6 feet of sea level rise by 2100 may be unlikely based on NOAA's current assessment (and ours, for that matter), sea level isn't projected to fall in the coming centuries - and we become much more likely to get to 6 feet by, for example, 2150.

And, of course, Zillow could re-run their analysis with a best estimate of 3 feet, and we would still see vulnerabilities emerge, both around the country and in our own neck of the woods.  Despite changing projections, and uncertainty, we gain by planning now to avoid future costly problems.  

Tuesday, September 26, 2017

Real resilience?

















A home on the Strait of Juan de Fuca still on blocks after being moved back from the beach.  Photo taken 16 September 2017

 In my line of work we spend a good bit of time worrying about the future of existing coastal development, and how society will respond to the pressures of climate impacts like sea level rise. If you are a pessimist you sort of see the future being made of walls along the coast that keep the rising sea away from homes and infrastructure. Its not hard to see the point of these pessimists. Indeed there are entire countries that are built on the principle of defending land against the ocean (though that approach is changing).

 















The costs of defending Washington's extraordinary coastline would be huge

 The environmental costs, not to mention the dollar sums, of the defense approach to coastal hazards can be huge, and as a result my impression has always been that other alternatives may be feasible, and even preferable, here in Washington State. But guide stars for other approaches have been few and far between. Over the last year, though, I had the very special opportunity to work with a family trying to protect their waterfront home from chronic erosion and flooding. The day that I visited they were still recovering from a few harsh storm years that destroyed parts of their existing rip-rap armoring, and drove debris right up to their home:

 

 When I first interacted with them the family was considering some upgraded armoring - the defense approach. The costs, though, were huge for the design and construction of an upgraded defensive structure to protect their home, and I emphasized to them that no defensive structure is permanent...they all require maintenance. We then talked through other options, including moving their home out of harms way. Notably in this case this option appeared to be cheaper than defense, provided a longer-term solution AND would provide easier access to the beach (impaired at the time by the rip-rap, as seen below in a photo from 2016 looking up the beach):

 















I was impressed by the family's decision-making process, and was inspired by their decision to move their home and remove their existing armoring. Astonishingly, once the decision was made the process happened quickly - the home was moved and the rip-rap removed by August of this year. The home is now out of harm's way, the beach is in better condition from an ecological and aesthetic standpoint...at this stage it seems to me like the optimal decision was made in this case.  Hopefully there will be an opportunity in the future to get a better sense from those involved regarding the relative costs and benefits of the chosen approach.

The view on 16 September 2017 from nearly the same point as the photo above.  A low scarp is all that remains of the formerly defensive rip-rap structure

In my book, though, this is real resilience at work. The Friends of the San Juans recently put together a little video telling a similar story from Orcas Island:

 

 There are lots of things that came together in both of these cases. Notably the families' had both the means and the space to move their home. But in my mind that doesn't take away from how big these decisions are, or what they mean for our future. We often default to defense, but careful cost-benefit analysis isn't always done. Where it is, I see more and more occasions in which defense emerges as a less-than-ideal option.

Friday, September 8, 2017

Communicating the changing Elwha marine community - Part 1



My last post was on Elwha diving, and I don't want to give the impression that its all I do...but while I was away on vacation (and missing the final week of this summer's Elwha dives) Alison Morrow from King5 news joined Nancy, Steve and Marshall for a day out on the boat.  And out of that day came the nice little piece above.

And that made me realize...we are putting a lot of effort right now into synthesizing the reams of data we've collected across a variety of projects, and packaging our observations and what we've learned.  There will be more to come, but amongst the recent developments includes this USGS Youtube channel specifically dedicated to archiving our undersea diver-collected videos of the seafloor around the Elwha River delta.   We also expect, soon, a paper summarizing the major coastal ecological stories from the dam removal, and an interactive map that will allow a user to quickly move through space and time to explore coastal changes associated with the dam removal.  Stay tuned!

Thursday, August 10, 2017

Sites and sounds from this summer's return to the Elwha sea-floor


An embarrassment of tube worm riches, site E2, July 31 2017

Last week was our first week of diving for our annual (since 2008) sub-tidal site monitoring effort in the marine waters near the Elwha River Delta (i.e. here and here). Overall my take away is that the system "looks" very recovered relative to during the peak of dam removal in 2013 and 2014 (i.e. see the two comparative videos here). Here is a recent example, Site H2 in 2013, during dam removal. In particular in this video pay attention right at the outset to the turbidity visible in the water column, as well as the general lack of algae:



we returned to that site this summer, and here is the look see:



and now on to just a few highlights from this year:

Observed for the first time in our surveys, the orange peel nudibranch (Tochuina tetraquetra). This thing was big...probably 6-8 inches in length...



fan hydroids



We work out of the US Coast Guard Base on Ediz Hook, and this massive ball of herring was at the dock the entire week



The world's largest barnacle, Balanus nubilus, at work


Observed at Site C1, something we used to see a bit before dam removal...a Bull Kelp (Nereocystis leutkeana) growing attached to a tubeworm (in this case Spiochaetopterus sp.). Typically Bull Kelp will attach to bedrock, boulders or large cobble.

Saturday, July 22, 2017

The greening of the Elwha delta

I was out on the Elwha delta over the last two days, working with the staff from the US Geological Survey and Department of Ecology on the roughly annual topo/bathy survey of the Elwha delta. My role is to collect grain size photos and sediment samples. As we were cruising around the delta this year I was struck again by how the vegetation is really taking off on the new delta deposits laid down during dam removal. The photo above was shot this morning looking north (towards Vancouver Island) from roughly where the "A" is on the map below: and here is the view from the same location in May 2012: Such an incredible transformation. A huge thank you to Emily Portillo from the Washington Conservation Corps for assisting with the grain size sampling over the last two days!

Friday, June 16, 2017

The dynamic coast



I've been geeking out lately on Google's Earth Engine time lapse tool, which I first learned about a few years back, and which is a startling accomplishment in and of itself.  Basically Google has hoovered up and integrated every Landsat image ever collected to create a continuous time lapse of the earth's surface dating back to 1984.  While those imagery are fairly coarse resolution (around 30m in most cases), they easily pick up large-scale coastal changes and coastal sediment dynamics (like the above, from the Pysht estuary on the Strait of Juan de Fuca where you can actually see fluvial sediment being transported on-shore over decadal time-scales)...which has led to my geekery with the tool.  Here are a few highlights from coastal Washington (with credit to Hugh Shipman for pointing to many of these awesome locations).



Above, the Elwha, with a few highlights, including of course the massive flux of sediment and formation of new estuary/river mouth bar complexes associated with dam removal, and the formation and transport of a few cuspate foreland type features on the east side of the delta.



oh man, the Dungeness River delta and spit...so much going on.  Westward transport of sand bars off of the delta, extension and evolution of the Spit, on-shore migration of off-shore bars...so very cool.



Grays Harbor inlet...so much going on here.



but maybe not so much as the Willapa Bay inlet, which also features Washington State's slow-moving erosion disaster at the neighborhood/town of North Cove:



Useless Bay on Whidbey Island is just an absolute conveyor belt of sand waves moving along the shallow sub-tidal:



and check out the Stillaguamish snaking into Port Susan:

Its not quite coastal (though it IS related) - watch glaciers on Mt Olympus shrink before your eyes:



And similarly, not quite coastal, but Oso:

Tuesday, June 6, 2017

Building ROVs on the West End

A team from Forks Middle School presenting their ROV to a group of judges
I am raising my kids on the Olympic Peninsula, and it takes a lot of work to feel like they have opportunities for enriching STEM activities that youth in more urban areas do.  And I'm saying that even though we live in Port Angeles, at 19,000 people the largest community on the Olympic Peninsula.  I can't even imagine what parents and students in some of the smaller and more rural communities on the west end of the Olympic Peninsula must experience.  To help in some small way to provide an opportunity is one of the reasons that I enthusiastically signed on to be a judge for the first ever MATE ROV Satellite competition, organized with help from the Olympic Coast National Marine Sanctuary, and held at the Forks, Washington pool on 20 May.

The Expeditioners from Lake Quinault School, presenting their poster.  This team won an award for, "Best Team Spirit" during the competition
This was my first ROV competition, and I must say that I was impressed.  The competition organization is phenomenal, with a rigorous system of rules and scoring.  Even more impressive was the effort put into the contest by the roughly 20 teams in attendance, representing schools from Lake Quinault, Taholah, Forks, La Push, Clallam Bay and Neah Bay.  Most of the teams represented were starting from the same point - in all cases that I saw starting from one of these kits - but from there teams diverged widely in terms of their solutions to the various challenges they needed to deal with.

The poster presentation and ROV for one of the teams from Clallam Bay High School, with some really nice engineering touches.  This team did a lot of trial and error testing, and came up with some innovations.

By way of example, check out this student from Lake Quinault School walk us through his team's ROV design:


So cool...so very cool.  I'm definitely in.

Monday, May 8, 2017

Moving pictures of all kinds...

We managed to pull off yet another year of the River and Ocean Film Festival (the 4th one!), which I organize each year along with the North Pacific Coast Marine Resources Committee.  As I told the audience this year I'm in to doing this because I think that film is such a great way to tell stories about the places we live, and allow people to see and experience views and perspectives about their landscape that they never would otherwise.  This year we had a great audience and great feedback, but if you were one of the many people that were NOT there you can see many of the films (along with those from previous years) here.

And since we are premiering films, I also wanted to point towards a set of videos that we, along with USGS and the Lower Elwha Klallam Tribe, just published on USGS's Youtube page.  They collect in one place all of the "transect" videos we've shot on the sea-floor around the Elwha delta...and since these videos are shot at a selection of "fixed" points you can sort of click through them to see how the sea-floor and coastal ecosystem changed through the dam removal.

Enjoy!


Friday, March 24, 2017

Glass Beach




I'm going to take a page out of Hugh Shipman's book here and take a stab at profiling a section of shoreline I had the opportunity to explore last weekend.  If you wander west from Port Townsend along the Strait of Juan de Fuca you will find a few treasures.

First, just a stunning, active, classic eastern Strait of Juan de Fuca bluff backed shoreline.  This stretch is complete with perplexing and beautiful stratigraphy, plenty of signs of active erosion,  and also plenty of futile efforts to control that erosion:

Next, beach glass!  This is why we went...to try to find a mythic glass beach that I had heard whispers of.  These sorts of places are scattered along the coast (including perhaps the most famous of them all in CA?), presumably related to old but poorly documented informal dump sites.  Beach-combing for glass is one of those things that everyone in our family seems to love, so it was a treat to try to make it to this well-known glass hunting beach:

As it turns out we didn't make it all the way to the best sites, but made it plenty far to scratch everyone's itch:


Friday, March 3, 2017

Anatomy of a Coastal Storm: March 10, 2016

Nuisance flooding in Freeland, Washington on Whidbey Island after the March 10 storm.  Unknown photographer, photo courtesy of Island County Department of Natural Resources.  
We are coming up on the one year anniversary of the 10 March, 2016 storm that really walloped many communities in northern Puget Sound (see this link as well) and on the Washington Coast.  It was an interesting storm for a variety of reasons and in particular it seemed to impact coastal areas in northern Puget Sound in ways that those communities were not accustomed to. Perhaps as a result I've heard people refer to the March 10th storm as a "100 year storm" from the standpoint of its coastal impacts.  As a result I wanted to use this blog to look in a bit more detail at some of the aspects of this event in in relationship to the coastal impacts associated with the event.

Overwash of sand, gravel and wood on to a road near Oak Harbor, Washington.  Photo courtesy of Lori Clark, Island County Department of Natural Resources
The photos above, and indeed many of the most significant impacts associated with this storm were focused in Island, Skagit and Whatcom Counties, but there is a distinct lack of tide gauge data up in those parts.  So I'm going to focus first on Port Townsend, where there is a tide gauge.  To be clear the storm was exciting there too.  The photo below shows a distinct debris line and nuisance flooding adjacent to the Jefferson Title Company building in Port Townsend on the morning of March 10:

photo courtesy of David Wilkinson
Here are the water level data collected between 5 March and 15 March, 2016 at the P.T. tide gauge, located just east of where this photo was taken:


When interpreting these data I am going to distinguish between three different water levels; first the "astronomical tidal water level", which I will also refer to as the predicted tide (shown in blue in these plots); next the non-tidal residual, which I will refer to as "storm surge", which is the difference between the predicted (or astronomical) tide and the measured water level (shown in purple in these plots); and finally the actual measured water level, or "still water level", which is the sum of the two (shown in green in these plots).

So in P.T. the total measured water level measured during this event WAS high - the peak measured on the morning of March 10 was 3.41 m relative to MLLW...but this is nowhere near a "100 year coastal flood water level" for P.T.  In fact since the current tide gauge was installed in 1972 that water level has been exceeded numerous times, with a maximum measured water level of 3.57 m relative to MLLW reached on 12/10/1993.  NOAA places the March 10, 2016 measured water level as having somewhere around a 1-in-5 year recurrence interval, or a roughly 20% chance of occurring in any given year.  Here is another way of looking at it:

These are histograms of hourly water level data dating back to 1972 in Port Townsend, with the metrics associated with March 10 in red.  At the top is the predicted or astronomical water level...and here the predicted tide on this day wasn't particularly high, but the NTR (the panel at the bottom) is pretty high, but again nowhere near the highest on record (that record was set on 1 Jan 1997 in Port Townsend when the non-tidal residual was roughly half a foot higher than the surge on March 10). So indeed, the "still water level", as measured at the tide gauge WAS indeed high, primarily because of some pretty good "storm surge", the peak of which more or less coincided with high tide...but nowhere near a 1-in-100 year event.

So what compelled us to look at March 10th as extreme?  Well, clearly wind, and wind-driven waves, played a major role in driving flooding during this event.  Here is another photo taken the morning of March 10, 2016, looking south from the south-facing shoreline of downtown Port Townsend:

Photo courtesy of David Wilkinson
There are no wind data available for that event from the P.T. tide gauge, so I turned instead to average wind data (these are averages over an 8 minute period) dating back to 2004 available from NOAA's Hein Bank buoy in the Strait of Juan de Fuca, and in particular wanted to look at winds blowing from the south, so trimmed those data to winds that were recorded as coming from between 120 and 210 degrees.  The histogram of those data suggest that extreme winds here would be those in the 18-20 kt range...


and on March 20 that buoy in the strait recorded peak average winds from the south on the order of 18 kts:


so pretty strong winds.  Again, not horribly strong from the standpoint of the available record dating back to 2004, but pretty strong.  So this leaves us with the notion that what MIGHT have been unique about this storm wasn't so much the relative magnitude of any of the individual processes at play (i.e. astronomical tides, storm surge, and wind) but rather the co-occurrence of these factors...i.e. what is the chance that you get a relatively high astronomical tide, coupled with a strong storm surge, coupled with pretty strong south winds that kick up relatively large wind waves (large by Puget Sound standards).  Taken together, maybe those things do amount to a pretty darn rare event, possibly even a 1-in-100 year event...but calculating that joint probability distribution will have to wait for a later date.


Tuesday, February 14, 2017

Nourishment in Washington State - A look at Ediz Hook

Looking west along Ediz Hook at nourish material place in January along the base of Ediz Hook.  Photo shot from a location immediately east of the paper mill at the base of the Hook (red circle in map below).
Shoreline nourishment, where sand and/or gravel is placed on the shoreline to change the profile or character of the beach, is a relatively infrequently used tool in Washington State, at least compared to other parts of the country.  In Western Carolina University's beach nourishment database, for example, Washington State ranks 4th to last in spending on shoreline nourishment, behind Maine, New Hampshire and Rhode Island.

Part of US Army Corps plans for nourishment on Ediz Hook that took place in January 2017.  This particular nourishment project was limited to the areas in the black box at the base of Ediz Hook.
Ediz Hook though, again based on WCU's nourishment database, is the most nourished shoreline in Washington's protected waters (i.e. in Puget Sound and the Strait of Juan de Fuca).  On Ediz Hook nourishment is primarily used, interestingly enough, to protect the large rip rap material that stabilizes Ediz Hook, and is placed every few years.  Just last month there was a placement of roughly (by my math based on the drawing above) 35,000 cy of sand and cobble to replenish the eroding beach at the base of the rip-rap on the west end of Ediz Hook.

Looking east from the location marked with a red dot in the map above.
 The last nourishment on Ediz Hook that I am aware of occurred at some point in late 2011.  I snapped this photo in January of 2012 from more or less the same location and perspective as the top photo in this post:


Ediz Hook, though, is nothing if not exceptional in its ability to erode material off of its steep shoreface, end even by early April (the photo below was shot on 8 April 2012) most of that material has been eroded off of the upper beach:


Pretty impressive. But certainly it did act to fortify the toe of that beach, as shown in this beach profile from that area that I post a few months ago:

The first profile above is from March 2012.  Of course over the subsequent years that section of beach has eroded chronically.

Monday, January 30, 2017

Shoreline morphology monitoring

Tera Dummitt, student at the Huxley College on the Peninsulas program, walking a beach transect line on Dungeness Spit
Whoa, three months since my last post...far too long.  Things have been too busy.  But in the depths of winter I'm remembering summer, and just wrapped up two reports documenting this year's efforts to measure shoreline morphology at beaches on the Olympic coast and on the Strait of Juan de Fuca. This is a tiny program, and one that I keep afloat largely by determination and donation, but I continue to believe that these types of data will provide us important perspectives in the future.

Ruby Beach with students from the University of Washington MeSSAGE program
Another special part of the program for me is the opportunity it provides to work with students.  This year in particular I had great support from the Huxley College Program on the Peninsulas, as well as the University of Washington MeSSAGE Program.

Along the way I also put together summaries on patterns or trends I find interesting.  A few recent examples are here and here.