Science Seminar Series Archives

Science Center Objects

Here are our past science seminars at the Pacific Coastal and Marine Science Center in Santa Cruz, California. Please check out our upcoming seminars.

Tuesday, May 21st, 2019, 1:00 PM

Lauren Toth

Two underwater divers wearing wet suits and oxygen tanks with an apparatus that is drilling into the seafloor.

USGS St. Petersburg Coastal and Marine Science Center

“Geological perspectives on the degradation and restoration of Florida’s coral reefs”

Abstract:
Over thousands of years, corals build complex geological structures that serve as the foundations for a myriad of critical ecosystem services. Ensuring that both ecological and geological reef functions are maintained is, therefore, critical to designing effective coral-reef management and restoration programs. Using the record of coral-reef development captured in reef cores collected throughout the Florida Keys reef tract, Lauren’s work provides a geological perspective on the management of Florida’s coral reefs with respect to processes like carbonate production and reef accretion. This talk will describe the Holocene history of coral-reef development in the region, the modern state of reefs with respect reef growth, and insights for optimizing future coral-reef restoration.

 

Wednesday, May 22nd, 2019, 2:00 PM 

Stuart Pearson

Delft University of Technology

"Sediment Transport Processes and Pathways at Ameland Inlet"

View looks down at a river outlet from the sky to illustrate various components of sediment transport.

Abstract: Which pathways does sediment follow at tidal inlets and on ebb-tidal deltas?  Quantifying these pathways is essential for estimating regional sediment budgets and answering key coastal management questions.  How will the coast respond to climate change or human interventions like dredging and nourishments?  These are especially pressing concerns for the Netherlands, where the country’s safety from flooding is directly dependent on the volume of sediment in its coastal system.

To improve our knowledge of sediment transport at tidal inlets and provide concrete guidance to the Dutch government about nourishment strategies in such environments, we conducted a field measurement campaign at Ameland Inlet, located in the Dutch Wadden Sea.  I will present a brief overview of our findings so far, and indicate future directions for our research.  We conducted a sediment tracer study on the ebb-tidal delta using fluorescent/magnetic sand, which has yielded insight into grain size sorting and dispersal.  We also measured particles in suspension on the ebb-tidal delta, and identified two distinct populations of suspended sediment. Estuarine fronts are persistent and ubiquitous in Ameland Inlet, and suggest a relationship between wind and density-driven flows. Lastly, we define a framework for quantifying sediment transport pathways in coastal environments, using the concept of “connectivity” as successfully applied in other disciplines. In the coming three months at USGS, I will be investigating sediment pathways at the mouth of the Columbia River.  We aim to apply this coastal sediment connectivity framework there, and to make a comparison with Ameland Inlet.

 

Two round, colored logos to signify the national oceanic and atmospheric administration and its coral reef conservation program.

Thursday, April 11th, 2019, 12:00 pm

Jennifer Koss

NOAA Coral Reef Conservation Program Director

“20 Years of Coral Reef Conservation Conducted from the 10th Floor of a Federal Office in Washington, D.C.:
How has NOAA approached coral reef conservation through changing administrations and ever-worsening conditions?”

Questions that will be answered in the talk:

a.     How has coral reef conservation evolved over the past 20 years?
b.     Typhoons, Disease, Hot and Sour Soup -- Just how bad is it for coral reefs right now?
c.     What are some of the potential game changers in coral reef conservation happening right now?

 

Wednesday, April 10th, 2019, 2:00 pm

Alan Nelson

USGS Geologic Hazards Science Center

“Searching for fossil subduction-zone earthquakes and tsunamis at 56°N and 44°S: A tale of two islands”

Abstract: 

The most direct, if not the cleverest, way to improve forecasts of the greatest earthquakes and highest tsunamis at subduction zones is to learn the history of the greatest events over the past few thousands of years. But finding sites with identifiable evidence of great earthquakes and tsunamis that can be dated is a tricky business—both scientifically and logistically. One might expect to find the most easily identified evidence of coseismic land-level changes and tsunamis nearest the megathrust plate boundary, where coseismic upper-plate deformation is greatest. At most subduction zones, the closest sites are on unusual islands near the edge of the continental shelf, but getting to and working at such sites brings special challenges not commonly encountered in paleoseismic studies.

Expeditions to two such islands—Chirikof Island near the Alaska-Aleutian megathrust west of Kodiak Island, and Isla Gaufo in south-central Chile southwest of Chiloe Island—offered contrasts in types of evidence and logistics. During our reconnaissance visit to Chirikof Island we found the first evidence of many tsunamis over many thousands of years along the Alaska-Aleutian megathrust. On Isla Gaufo continuing studies of dramatic historical and prehistoric land-level changes accompanied by high tsunamis add depth to the rapidly developing earthquake and tsunami history of southern Chile. The Gaufo data also constrain models of upper-plate deformation in this region at several scales.

Two photographs side-by-side, on left is a beach with arrows and words superimposed, on right is a river bank with people.

 

A man wearing a floatation vest and mud boots walks though a very muddy marsh area carrying a bag, while a jumbo jet flies over.

Tuesday, April 2nd, 2019, 2:00 pm

Neil Ganju

USGS Woods Hole Coastal and Marine Science Center

“Marshes are the new beaches: integrating sediment transport into restoration planning”

Abstract: 

Recent coastal storms and associated recovery efforts have led to increased investment in salt marsh restoration due to their coastal protection benefits. Millions of dollars have been allocated or spent because of their perceived sustainability and ecologically positive co-benefits including habitat provision and carbon sequestration. However, these projects are often planned without full consideration of the sediment transport processes that control their sustainability. I contend that before significant investments are made in marsh restoration, sediment transport measurements and models that consider sediment dynamics should be integrated into the early phases of restoration planning. This will help identify where and under what conditions marsh restoration will most likely be successful and economically justified. Triaging and prioritizing is then possible, which is a sustainable approach for restoration, given the persistent vulnerability of marshes to sea-level rise, storms, and sediment deficits.

 

Man wearing safety gear stands ion beach near piles of sand bags lining grassy shore, nearby earth mover moves sand.

Wednesday, February 27th, 2:00 PM

Sean Vitousek

USGS Pacific Coastal and Marine Science Center

“Modeling Coastal Change: Past, Present, & Future”

Abstract:

Understanding and predicting coastal change depends on integrating data on natural systems with computer simulations.  Although many computer modeling approaches are available to simulate shoreline change, few are capable of making reliable long-term predictions.  Recent advancements have allowed convincing decadal to centennial-scale predictions of shoreline evolution. However, long-term coastal evolution, caused by the interaction of many geologic and hydrodynamic processes, is notoriously difficult to understand let alone predict. In this talk, I discuss my past, present, and future research efforts related coastal change.

 

Cartoon showing water being injected into various depths and the potential sizes of earthquakes labeled as stars.

Wednesday, February 13th, 2:00 PM

Thomas H.W. Goebel

Earth Sciences, UC Santa Cruz

“The spacial footprint of fluid-injection wells and induced earthquakes”

Abstract:

The assessment and mitigation of induced earthquakes remain a crucial scientific and societal issue in light of the on-going induced seismic activity in the central United States and newly emerging earthquake sequences related to fluid injection and hydraulic fracturing in Western Canada.

Fluid injection induced seismicity is commonly inferred to be driven by increasing pore pressures that infiltrate faults and allow
earthquakes to occur. However, this inference is challenged by induced sequences with observed far-field triggering. To unravel triggering mechanisms of injection-induced earthquakes, we examine the spatial seismicity decay from wells using a unique global compilation of induced earthquake sequences. We find many sequences, that show a power-law-like decay out to more than ~10 km distance from the well. The shape and extent of this decay can be explained by the complex coupling between fluid and solid elastic stresses. Elastic stresses result in far-reaching induced seismicity sequences which increase seismic hazard beyond expectations from previous models.

 

Map showing 3-D relief of the central California coastline, with fault lines labeled and drawn on top.

Wednesday, February 6th, 2:00 PM

Sam Johnson

USGS Pacific Coastal and Marine Science Center

“The Northern San Andreas Fault: A Coastal and Marine Perspective”

 

Two photos taken at different times from the same spot in from the sky show a river that flows into an ocean bay.

Weds., Sept. 12th, 2018, 2:00 PM

Mara Orescanin

Naval Postgraduate School

"Hydrodynamics and morphodynamics of a small bar built estuary: The Carmel River, CA"

Abstract:

The Carmel River is an ephemeral river/bar built estuary located in southern Carmel Bay, that is bounded by rocky headlands to the south and north of the 700m long pocket beach.  Observations are presented showing the hydrodynamics during the breaching and closure events that occurred during the transition from dry to wet seasons during winter 2016-2017. These observations suggest no correlation for breaching events with either tides or waves.  However, each closure event occurs during high tide with large waves. Morphological measurements made during the 2017-2018 winter show a net influx of sediment to the system during the winter months along with an onshore migration of the beach. In addition, the hydrodynamic and morphodynamic response of the system to mechanical breaching is assessed. 

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Collage of an underwater photo above and a computer model output below, photo is murky with reef, sand, and instrumentation.

Sample slide from seminar presenter's talk in July 2018.

July 25th, 2018, 2:00 pm

Andrew Pomeroy

University of Western Australia

“The impact of bathymetry and roughness on the transport of reef generated sediment”

Abstract: The three-dimensional structure of coral reef bathymetry and bottom roughness affects the hydrodynamic processes that mobilize and transport sediment. These processes vary both spatially and temporally due to the physical characteristics of the reef. Attempts to describe sediment suspended from the bed have typically focused on correct representation of these hydrodynamic processes (which can be readily measured) with bottom friction parameters often adjusted until predicted wave heights and flow match field measurements. While this approach yields ‘correct’ representation of the hydrodynamic processes, large roughness substantially alters the boundary layer structure. Sediment transport equations do not account for these boundary layer changes and this has important consequences for the prediction of sediment dynamics in these environments. This seminar will focus on what is known about the type of sediment being transported, the contribution of different physical processes as well as how a range of new techniques are being combined to improve insight into how sediment transport processes in reef environments. 

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A series of 4 circles running left to right, divers underwater, ocean waters with red contamination, flooded street, and canoes.

Introduction to NOAA National Centers for Coastal Ocean Science (NCCOS)

June 21st, 2018, 11:00 am

Steven Thur

NOAA National Centers for Coastal Ocean Science (NCCOS)

“Introduction to NOAA National Centers for Coastal Ocean Science (NCCOS)”

Abstract: The United States has been endowed with a tremendous asset: our ocean and coastal resources. The facts are incontrovertible. Coastal counties contribute over $6.6 trillion to our nation’s gross domestic product, which is nearly 50 percent of national output. Approximately 40 percent of U.S. citizens live in these counties, attracted by both the natural beauty of the coasts and plentiful employment opportunities. It is here that Americans live, work, recreate, and seek to reconnect with nature.

With such a concentration of human activity, there exists the potential for conflict between various uses of these resources. In addition, the coastal environment is a dynamic place; sea levels change, natural resources shift, patterns of human use vary, and industries wax and wane. Officials at the local, state, tribal, and federal level, along with those in the corporate and nonprofit sectors, must use the best available information to make decisions that affect livelihoods, property values, human health, preparedness for disasters, management of our natural resources, and protection of special places for future generations.

Our role is to conduct the research and provide the information necessary to address these complex coastal challenges. The mission of the National Centers for Coastal Ocean Science (NCCOS) is to deliver ecosystem science solutions for stewardship of the nation’s ocean and coastal resources to sustain thriving coastal communities and economies.

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View from the sky looking down on a coastal area with houses on winding streets near a beach, painted lines trace the coast.

June 13th, 2018, 2:00pm

Doug George

Greater Farallones National Marine Sanctuary (GFNMS) and Central and Northern California Ocean Observing System (CeNCOOS)

“The Sediment Swirl: Knowledge Gaps in Sediment Transport Along the North-Central California Coast”