Soaring over King Tides

A GLIMPSE OF WHAT WE’VE ALREADY SEEN AND WHAT WE MAY SEE IN THE FUTURE

ByNick Sadrpour, USC Sea Grant Science, Research & Policy Specialist February 26, 2019

On the morning of January 22, 2019, I hopped on board LightHawk volunteer pilot Bill’s single-engine plane to see what the morning’s 6.8-foot King tide had in store for the Southern California coast. Immediately after take-off, we were struck by the immense development of our urban coast: ports, freeways, apartments, golf courses, houses, industrial facilities, parking lots. As we hooked south from Torrance airport, we saw a dense mix of human development and natural features. The fragmentation of Los Cerritos Wetlands, the channelized LA River, the relatively natural Seal Beach National Wildlife Refuge, and the engineered community of Naples illustrated dramatically how human intervention and ingenuity disrupt natural systems – still visible but greatly disturbed.

View of Santa Monica Bay just after take-off from Torrance Airport.

When it comes to understanding how our coast changes and thinking about a future with greater rates of sea-level rise and coastal change, a unique opportunity comes in the form of King Tides. King Tides are the colloquial term for the most extreme high tides of a year. These perigean spring tides occur as the result of astronomical phenomena associated with the position of the earth in relation to the sun and moon and their subsequent gravitational pull. These natural and predictable occurrences (although infrequent, roughly twice a year) provide insight into present vulnerabilities from the higher water levels and a future where higher water levels become normal conditions.

I was invited by Surfrider Foundation and LightHawk as we soared over the coast with Arielle Duhaime-Ross, VICE News Tonight’s environment and climate correspondent, as part of a national collaboration to catalog and observe King Tides. More than 20 flights covered key areas along the Pacific and Atlantic coastlines to promote awareness of coastal vulnerabilities and provide insight for present and future coastal management.

Because of the active and dynamic nature of California’s coastal environment, true risk comes in the form of high tides and higher sea level, in combination with swell and/or storm events (i.e. rain). It is when these factors align, say a significant swell and higher tide, that California’s coast experiences substantial erosion and flood vulnerability. Although the recent significant swell had subsided a few days before, the higher tide gave a glimpse of what sea level rise might look like. Hooking back northward around San Pedro brought other natural hazards to the forefront. From Sunken City to White Point and Portuguese Bend, landslides of the past and the potential for them in the future was perceptible. Although those natural hazards were not associated with climate change, seeing whole sections of bluff slump and what impacts these have on coastal communities demonstrate dramatically how climate change will affect our coastal areas.

Flying over Abalone Cove looking South over Palos Verdes.

As our group proceeded further up the coast, the beauty of Santa Monica Bay was ever present. Cities of Torrance, Redondo Beach, Hermosa Beach, Redondo Beach, El Segundo, Los Angeles, Santa Monica, and Malibu all stretched out to the horizon. Here, too, human intervention is clear, although slightly less immediately visible. In the early to mid-1900’s over 35 million cubic yards of sediment were placed on Santa Monica Bay beaches. In some areas, this nourishment caused beaches to widen by hundreds of feet, completely transforming the area into the wide sandy beaches we know today.

Santa Monica Beach in 1948 (left) after beach nourishment and in 1931 (right) before beach nourishment. Image courtesy LA Coastal Regional Sediment Management Plan.

Passing over the community of Venice gave a new perspective to USC Sea Grant’s current efforts to assist the City of Los Angeles on updating the Local Coastal Program (LCP) for this area through our AdaptLA initiative. Our work of understanding current management practices, continuing and pressing vulnerabilities, as well as adaptive management solutions (such as dune restoration) attempt to bridge the gap between research and policy. Seeing the Venice Breakwater nearly completely submerged by the King Tide clearly illustrated how our current experience will not be what future beach goers to this area see. The Venice Breakwater is a vestigial artifact of the previous Venice Pier. What once protected an ocean abutting roller coaster now helps stall sediment transport, creating some heterogeneity in the sand bars and thus a little more shape to surfing waves than other areas nearby. It is wild to think of how much manmade change this coast has already seen. Moreover, how much it will see in the next iteration of long-term coastal management.

Left: Venice Breakwater during the king tide on January 22, 2019 (credit Lindsey Jurca). Right: Venice Pier with the Breakwater in the foreground before it was nourished, at Windward Ave circa 1930’s (credit Los Angeles Public Library).

Left: Malibu Lagoon during a king tide in November 2016 (credit USC Sea Grant). Right: Malibu Lagoon during the king tide on January 22, 2019 (credit Lindsey Jurca).

Returning to Torrance airport, our group reflected on what we saw today and how that will shape our understanding of coastal issues like sea level rise. Luckily, due to the kindness of volunteer pilot Bill, another set of folks were also going to have the opportunity to see LA’s coast during a King Tide. On the next flight passengers represented LA County Department of Beaches and Harbors, LA Waterkeeper, and the Los Angeles Chapter of the Surfrider Foundation. This flight’s mission was to see the impact of the King Tide on the coasts of northern Santa Monica Bay and Malibu.

Even without a birds-eye view, any interested community member can help document coastal change and contribute to a catalog of dynamic coastal change. Through USC Sea Grant’s Urban Tides program, we encourage everyone to take photos of coastal places that are important to them. These observations about how and where the coast is changing will help further the collective dialogue about how we can adapt to rising seas. It is through efforts like these where communities become more connected to their environment and can be a part of its long-term stewardship.

USC Sea Grant wholeheartedly thanks LightHawk and Surfrider for this incredible opportunity. Through the generosity of volunteer pilots, a nationwide fleet carried elected officials, photographers, subject experts and reporters over coastal areas to witness extreme high tides and collect aerial images. These flights aim to bring awareness to and encourage people take action on climate change, and spread compassion for coastal communities, habitat, and ecosystems that will be impacted by rising sea levels and climate change. USC Sea Grant’s interview with VICE News Tonight is yet to be released, so stayed tuned!