Monthly Archives: May 2019

If a fault moves at the bottom of the ocean, can anyone hear it?

A few hundred miles off the coast of Oregon, and under several miles of sea water, lies the Blanco Transform Fault. It is between the Juan de Fuca and the Gorda tectonic ridges. Ocean transform faults such as this one connect seafloor ridges and are where volcanic activity creates new oceanic crust. This fault is more seismically active than many faults on land, generating over 1,600 earthquakes in a single year (between 2012 and 2013). Did you feel anything then?

Location and tectonic setting of the Blanco Transform Fault.

Vaclav Kuna, a doctoral candidate in seismology in the College of Earth, Ocean and Atmospheric Sciences working with Dr. John Nabelek, is studying this fault—how it slips and how it moves, and whether its motion is seismic (involving an earthquake) or aseismic (slow movement without an earthquake). A collection of movements is called a seismic swarm. The hypothesis is that prior to large, seismic motions, there are small, aseismic motions. Through his research, Vaclav hopes to decipher what occurs in a swarm, and discover if there is a pattern in the fault’s motions.

The model Vaclav is working to develop of the mode of slip of the Blanco Transform Fault. We believe that slow (non-seismic) creep occurs at depth in the fault beneath the Moho and loads the shallower part of the fault. The slip at depth most likely triggers the big earthquakes, that are preceded by foreshocks associated with creep.

This is different than predicting earthquakes. As a seismologist, Vaclav is trying to understand and report on the behavior of a fault, not predict when a certain magnitude earthquake will occur. However, other researchers can use findings like Vaclav’s to create prediction models which are necessary for earthquake damage mitigation and increasing public safety during and after earthquake events.

To look for patterns in the fault’s motions, Vaclav analyzes a year’s worth of data from seismometers and pressure gauges that were deployed from a ship to the fault at the ocean floor several years ago. The seismometers measure the velocity of a fault’s movement in three directions (two horizontal and one vertical), and the pressure gauges act as microphones capturing sound waves. The data can be decomposed into a series of many waves (like sine or cosine waves). Vaclav can track these waves in the sensors deployed along this fault and determine the variability of motion in both time and space. After the sensors are finished collecting the data, a remote control turns on an electrical circuit, that triggers a corrosion reaction and severs a wire holding a large weight that is keeping the sensors at the ocean floor—which seems like something taken right out of a spy movie.

Deployment of ocean bottom seimometers (yellow packets) at the Blanco Transform Fault. Every packet includes a 3-component seismometer and a differential pressure gauge (which acts as a microphone).

So why would a researcher monitor a fault that is miles underwater when there are faults on land? Ocean transform faults are less complex than faults on land, making them desirable to study in order to answer fundamental questions about fault behavior. In addition, they are extremely seismically active and generate earthquakes more frequently than faults on land. However, ocean transform faults are evidently more difficult to observe, and because the process of planning for and conducting fieldwork is time-intensive, most of the data Vaclav uses were gathered before he was enrolled at OSU. In turn, Vaclav helps deploy sensors and gather data for future students to analyze at a number of different faults around the world.

Vaclav at a station deployment at the Kazbegi mountain, Georgia (Caucasus mountain range).

Vaclav did his Bachelor’s and Master’s degrees in Geophysics in Prague, Czech Republic. He was motivated to study Geophysics because there is a lot that is unknown about how the Earth’s tectonic plates move, and many people living near these faults. In his spare time, Vaclav likes swimming, running, skiing and kayaking. After completing his PhD, Vaclav wants to find a job working towards hazard-related mitigation to help people who are vulnerable to the damages caused by earthquake hazards.

A bird’s eye view: hindsight and foresight from long term bird surveys

The Hermit Warbler is a songbird that lives its life in two areas of the world. It spends its breeding season (late May-early July) in the coniferous forests of the Pacific Northwest (PNW) and migrates to Central America for the winter. Due to the long journey from the Central America to the PNW, it is dependent on food resources being available throughout its journey and when it arrives to breed. The environmental conditions across its range are tightly linked to habitat resources, and unfavorable climatic conditions, such as those becoming less frequent due to climate change, can negatively affect bird populations. Changes in bird populations are not always easy to notice, especially with small songbirds that live high in tree canopies. Studying birds for one or a few years may not be enough to signal the change in their well-being.

A Hermit Warbler singing on a lichen-covered branch in the forest canopy. Male Hermit Warblers will defend their territories ferociously against other males during the breeding season. H.J. Andrews Experimental Forest, May 2017.

Fortunately, long term data sets are becoming more available thanks to long term study programs. For example, the Willamette National Forest in Oregon is home to H. J. Andrews Experimental Forest (the Andrews). Designated by the USDA Forest Service Pacific Northwest Research Station, the Andrews forest hosts many forest research projects and has been monitored since 1948. In 1980, it was became one of the National Science Foundation’s Long Term Ecological Research sites ensuring that it will remain a resource for scientists for years to come. Bird surveys at the Andrews began 11 years ago, and researchers at Oregon State University are beginning to draw connections between changing climate and bird communities in relation to the forest’s structure and compositions.

H.J. Andrews Experimental Forest, where long-term bird study is launched in 2009 by Drs. Matt Betts and Sarah Frey. The forest sits on the moist foothills of western Cascades in Willamette National Forest.

One of these researchers, Hankyu Kim PhD student in the Department of Forest Ecosystems and Society, is using this data to study the Hermit Warbler and other bird species at the Andrews. Hankyu is interested in how and why bird communities are changing over time. With 11 years of bird observations and extensive temperature data, he is attempting to estimate how population of birds persist in the forests. To begin approximating how current climate effects birds, we need to have an idea about bird communities in the past. Past conditions can help us explore how birds might respond to future climate scenarios. Without the effort of many researchers before him to monitor birds, his investigation would be impossible.

Bird surveys are conducted via point counts. Researchers stand at a point count station for 10 minutes and count all bird species they see and hear. Listen to a hermit warbler and some other background birdsongs recorded at H.J Andrews in June 2017.

Hankyu realized the importance of long-term data after reviewing the 45-years of wintering waterbird surveys collected by the Birdwatching Club at Seoul National University, Korea during his time as an undergrad. The group took annual trips to the major Rivers and Coastal Areas, and in just a couple decades the members of the club had recorded declines and disappearances of some species that were once common and widespread. This finding inspired Hankyu to pursue graduate school to study unnoticed or uncharismatic species that are in danger of decline. Every species plays a critical role in the ecosystem, even if that role has not yet been discovered.

Tune in on Sunday May, 19 at 7 pm to hear more about Hankyu Kim’s research with birds. Not a local listener? Stream the show live or catch up when the podcast episode is released.

Want more about the Hermit Warblers in Oregon? Check out this video of Oregon Field Guide featuring Hankyu and some of his colleagues from Oregon State University.

This time, it actually is rocket science: computational tools for modeling combustion

A.J. Fillo is in his final year of his PhD in Mechanical Engineering in the School of Mechanical, Industrial, and Manufacturing Engineering, within the College of Engineering. Working with Dr. Kyle Niemeyer. A.J. is studying combustion, or how things burn; specifically, A.J. is working to better understand how the microscopic motion of molecules impacts the type of combustion that we use in jet engines.

From A.J.’s masters work, and an photo-art series A.J. did on combustion, Turbulent, premixed jet fuel air Bunsen burner with a fuel rich jet fuel air flame. Fuel is commercially available ‘Jet-A.’ Photo shot at 1/8000 second shutter speed and aperture of f/2.8

            To understand combustion, first it’s helpful to understand energy.  If you drop a ball at the top of a hill, it will roll to the bottom, if you place a tea bag into a hot glass of water, the flavors will move through the water until you have tea. Both of these processes take something from its high energy state, to a more stable lower energy state. In our tea cup, molecular diffusion is what moves that energy around. Diffusion is the process of molecules becoming evenly dispersed by moving from high to low concentration and happens at very small scales, and affects everything around us including the combustion that we use in jet engines.

Diffusion is only part of the story though.  In fluid mechanics, the study of how gasses and liquids move around, diffusion controls the smallest aspects of motion but what processes control motion on a larger scale? To answer that A.J. used the example of an airplane wing. In physics class, many of us have seen a drawing or a demonstration of an airplane wing with smooth streaks of air flow over it, we call those smooth air streaks streamlines.  These smooth streamlines represent something called laminar flow, which is very smooth and predictable, but fluid flows are rarely predictable, usually they are swirly, changing, and chaotic.  These chaotic flows are called turbulence and exist all around us, they cause planes to bounce around when we fly through rough air, they drive the little vortex tornado the forms when our sink drains, and they can even impact the motion, structure, and chemistry of a jet fuel flame.

2D slice of a 3D simulation results for a turbulent, premixed, n-heptane air flame looking at flame temperature. Flow is from left to right.

Both turbulence and diffusion work to move energy around in combustion, but we don’t yet have a firm understanding of how these two different processes interact to control the combustion we use to propel us through the air.

Turns out, flames are hard to study because as you can imagine, anything you would use to measure a flame, does not want to be in a flame; measurement tools like thermocouples and pressure transducers can melt, or even combust themselves.  But there is another tool at our disposal.  We can use super computers to simulate how combustion is happening in jet engines and even use it to study how turbulence and diffusion interact, or how molecules are moving around during combustion.

From A.J.’s masters work, and an photo-art series A.J. did on combustion, Turbulent, premixed jet fuel air Bunsen burner with a fuel lean jet fuel air flame. Fuel is commercially available ‘Jet-A.’ Photo shot at 1/8000 second shutter speed and aperture of f/2.8

A.J.’s research focuses on developing computational tools to look at these effects. The sum total of reactions happening during jet fuel combustion are large and complex, meaning that the equations are not easy to solve, and trying to do so can take thousands of computer cores for several days. By developing a more efficient computer algorithm to look at these reactions we can make these simulations faster, more efficient, and less expensive.

In reality, Jet fuel is a mixture of hundreds of different chemicals, so to simplify things, A.J. uses fuels like hydrogen (H2), n-heptane (H3C(CH2)5CH3), and toluene (C6H5CH3) as representative fuels. Although a single, simpler compound, even as simple as just hydrogen, has hundreds of chemical reactions and dozens of different radical molecules that form during its combustion. To get around the limitation of computer memory and speed up how quickly his simulations run, A.J. created an algorithm to optimize how the computer handles the math to make sure things run as smoothly as possible.  You can think of it a bit like going to the DMV, usually the line takes forever because people are rarely ready with their paper work in hand when they get to the front of the line, instead people must get out of line, get more paper work, and start over.  Using this analogy, A.J.’s algorithm works to make sure everyone in line arrive with their paper work completed, ready to hand off, and let the next person through. This reduces dramatically reduced the amount of computer memory needed to solve these combustion simulations and speeds up the math.

3D simulation results for a turbulent, premixed, hydrogen air flame looking at peak flame temperature colored by chemical composition. Flow is from back to front

A.J. became interested in mechanical engineering because of his love of magic. A.J. started his academic journey at the University of Missouri Columbia as a journalism major but transferred to OSU for the engineering program. A.J. has always loved performing, which is why science outreach has been such a large part of his graduate school experience. Partnered with the Corvallis Public Library, A.J. hosts LIB LAB, a hands-on multimedia educational YouTube series focused on STEAM (science, technology, engineering, arts, and mathematics) education, which he previously talked about on our GRADx event.

A.J. standing with the Oregon State University Drumline in OSU’s Reser Stadium while filming an episode of his YouTube show LIB LAB about vortex smoke rings.

To find out more about A.J.s research, outreach, and journey to grad school, join us on Sunday, May 12 at 7 PM on KBVR Corvallis 88.7 FM or stream live.


Improving hurricane prediction models using GPS data

GPS satellites orbiting the Earth

Exploiting a flaw in the system

GPS was originally designed for positioning, navigation, and timing (PNT) applications which measures the transmitted time of the radio signals from a satellite in the space to a receiver on the ground. But this story is not about improving GPS accuracy in navigation applications, rather it is a clever use of the GPS signal delay to collect data for monitoring the atmosphere for use in weather event predictions.

The transmitted GPS signal contains not only the range information, which is the primary factor of interest, but also error sources, such as atmospheric delay including tropospheric delay. The delay in GPS signals reaching Earth-based receivers due to the presence of water vapor is nearly proportional to the quantity of water vapor integrated along the signal path.

GPS is capable of seamless monitoring of the moisture in the atmosphere with high temporal and spatial resolution. Excellent GPS data availability enables unique opportunities for data analysis and experimental studies in GPS-meteorology.

This week’s guest, Hoda Tahami, is a third year PhD student in Dr. Jihye Park’s geomatics research group in the Department of Civil and Construction Engineering. Using geomatics – the science of gathering, storing, processing, and delivering spatially referenced information – Hoda is working to improve weather models for hurricane prediction.

GPS Meteorology: Estimating vertically integrated atmospheric water vapor, or perceptible water, from Global Positioning System (GPS) radio signals collected by a regional network of ground-based geodetic GPS receiver.

Using GPS signal data for hurricane prediction

Data from Hurricane Matthew that hit Florida in 2016 has been used to explore the idea of using GPS data to predict the path and intensity of hurricanes. “I found a clear correlation between [signal delay] and other atmospheric variables, like temperature, precipitation, and water vapor,” says Hoda. This information can be used for weather models, which rely on quality observational data. Weather models are computer programs that apply physics to observations to make predictions. The set of observations forming the starting point for the model simulation are called the initial conditions. Hoda hopes that this new set of data can be used as an initial condition for existing atmospheric models.

This new set of GPS-based data provides an increase in temporal and spatial resolution. While many satellite data sources provided data every few hours or even just once or twice a day, Hoda explains, “The time scale in my data is in seconds. We average it to five minutes, then use it to make one to twenty-four hour predictions.” This new set of data can be used to complement existing data sets – each with their own caveats – used by agencies like the National Hurricane Service, National Oceanic and Atmospheric Administration (NOAA), and the National Weather Service.

More information about the proposed model can be found at:

Hoda Tahami with her poster at the Graduate Research Showcase at Oregon State University

Finding a love for geospatial research

Hoda began her career in civil engineering with a bachelor’s degree at K. N. Toosi University of Technology in Tehran, Iran. This was Hoda’s first experience with geospatial data and geographic information systems (GIS), which piqued her interest and led her to pursue a Master’s degree specializing in GIS. Due to the state-of-the-art geospatial research resources available, Hoda chose to pursue her doctorate degree at Oregon State.

Join us on Sunday, May 5 at 7 PM on KBVR Corvallis 88.7 FM or stream live to learn more about Hoda’s geospatial research and journey to graduate school.