SFVF- SP Crater and friends

Hi,

This last week I went out with a local geologist on a field trip to visit SP Crater and its friends. Ken Walters was my guide on our adventure. I picked up some cool rocks that are good examples of tephra.

We drove north on Highway 89 past Wupatki, then turned left on a unmarked dirt road. We passed many Babbitt cows on our way to SP's neighboring cinder cone pictured below.

 This cinder cone* is older than SP because of all the vegetation covering its slopes. It is interesting to note the small cinder dome in the center of the volcano showing that even after the cone stopped spewing lava into the air, there was still activity. It also seems the the side of the cinder cone was blown out at some point as that side of the volcano is lower than the rest.

Looking at a map of the SFVF helps to visualize the location of these volcanoes. If you can see on the map, there is a fault labeled "Doney Park Fault." This fault can be easily seen from both SP Crater and the cinder cone discussed above.

Our nest adventure was up the side of SP Crater or **** Pot Crater because it looks a lot like a toliet.

Formidable right? Although only 800 feet high, it was a steep hike with loose cinders so you were constantly trying to not slid backwards. The volcano is about 71,000 years old. Below you can see some good examples of flow patterns. Apparently quarters are the standard tool for gauging size, but since I didn't have any I utilized a normal chapstick. Notice the curves and seeming rough texture. This was caused by the lava being squeezed out of the ground, much like the shape of frosting coming out of differing tubes. Also shown is the middle of the volcano. Like its neighbor, SP mostly erupted lava and rocks that fell back down around it, thus creating the cinder cone we see today.

SP mostly spewed out basalt, but towards the end of its life the magma burst through the bottom, creating a black lava flow across the ground. The lava flow was quite sharp and treacherous, but ion some places one could see how the lava fit together before it got weathered and broken apart.

Scientists are still unsure where the magma came from to cause the formation of these volcanoes, but there are two theories: 1) like Yellowstone, the SFVF is sliding over a "hot spot" in the mantle that has caused string of volcanoes seen starting out near Williams and stretching beyond Flagstaff onto the Navajo Reservation, or 2) a chunk of the lithosphere is sliding under a denser part of lithosphere and the rock is melting because it is coming into contact with warmer temperatures and higher pressure. Whatever the source is, we do not know where it is from or when it will reveal itself next...

Rachel signed out.

*The name of that cinder cone is Colton Crater.

Kilauea, Hawaii (No it is not about a dream vacation)

Case Study

Name: Kilauea
Location: Hawaii
Type of Volcano: Shield, Caldera, Pyroclastic cone
Elevation: 1247 m (4091 ft)
Rock type: Basalt
Hazards: Lava Deltas, Vog, Lava Flows, Gases (SO2), Earthquakes, Tsunamis, Tephra jets, Steam Blasts, Acidic Fumes, Glass Particles, Scalding Waves, Ash Clouds and Plumes
Monitoring: Seismographs, Tiltmeters, EDM, GPS, Satellite, Thermal and Regular Cameras, Gas Emissions
Last Eruption: Whenever you are reading this. Last explosive eruption occurred in 2011
Current Status: Active
Current Activity: Eruptions in summit and East Rift Zone, ground deflation, lava lake lowered from 33 m to 46 m below the rim of Overlook Crater, low seismic activity (as of 8:56 am February 19, 2016) 

Afternoon,

Today we will discuss Kilauea. It is probably the most famous volcano of Hawaii with two million annuals visitors to the Hawaii Volcanoes National Park. If you have ever seen pictures of lava flows or lava fountains in Hawaii, then you have already seen Kilauea. It is the youngest volcano in the world and the most active as almost everyday there is eruptions occurring in the summit or East Rift Zone. With its ongoing eruptions, Kilauea has buried 45 square miles of volcano and added 560 acres of new land to the island.

The volcano has a large explosive eruption about as often as volcanoes like Mt. St. Helens, but has continuous smaller eruptions taking place.Many times these eruptions are hazardous to the people living on the island of Hawaii. For example, in 1986 a lava flow cut through the town of Kapa’ahu destroying homes and caused a highway to close. In 2011, another flow from the Pu'u 'O'o crater destroyed homes. Most recently, in the autumn of 2014, a lava flow threatened the community of Pahoa. It again destroyed some homes, but also crossed streets, moved along the cemetery driveway before turning into a pasture.

However, the most important takeaways from Kilauea have to do with predicting eruptions. Before a summit eruption, the caldera's floor usually drops and seismicity and gas output increase. McGuire (1995) found that seismic and ground deformation measurements have been the best ways to forecast eruptions at Kilauea. Ground inflation within the summit region that is accompanied by distinct, short period seismic events generally signals a replenishment of the magma reservoir. Later events include a sudden deflation of ground followed by an increase in the frequency of longer seismic events that illustrate an intrusion of magma into a rift. Because Kilauea has been monitored for over 100 years, there is an abundance of data on the volcano. This data allows scientists to more easily predict eruptions.

Because Kilauea is a continuous eruption, different techniques can be tested and developed by monitoring it remotely because it is also being monitored closely from the ground. Data is be shared from the satellites and the ground instruments to understand how to calibrate satellites correctly so that they can be interpreted accurately.

Again though, volcanoes are still mysteries. Even Kilauea with all the scientists and instruments watching it is able to erupt with no warning. 

But it does have a cool feature. There are live webcams on the Hawaiian Volcano Observatory website: http://hvo.wr.usgs.gov/cams/

Here is a picture of the lava lake from today.

Until later,

Rachel
 

Mauna Loa, Hawaii... Not exactly Mustafar

Case Study

Name: Mauna Loa
Location: Hawaii
Type of Volcano: Shield, Caldera
Size: 4,169 m (13,679 ft)
Rock type: Basalt
Hazards: Lava Flows, Gas Emissions, Lava Fountains, Earthquakes, Ground Movement, Vog (Volcanic Smog)
Monitoring: Seismographs, Tiltmeters, GPS
Last Eruption: March 25-April 15, 1984
Current Status: Active
Current Activity: No eruptions, but some seismic activity and ground movement.

Hi,

This week I have been researching the volcano Mauna Loa ("Long Mountain") located on Hawaii Island. Mauna Loa is the largest volcano in the world. It covers more than half the island. It is concerning that this island also has the fastest growing population in Hawaii. Residents are encouraged to learn about the hazards the volcano poses so that they are prepared for eruptions. Unlike Flagstaff, this shield volcano gives evidence of its active status. There are rifts on the volcano, which release gases and sometimes lava.

Mauna Loa is part of the Hawaiian island chain. This volcanic chain was created by a hot spot (a place in the earth's subsurface where magma has risen into mantle) that the Pacific Plate is passing over. While Kilauea is one of the most active volcanoes, Mauna Loa is classified as active and is predicted to have a large eruption within our lifetimes.

The most famous eruption of Mauna Loa occurred in 1984. Scientists started recording an increase in shallow and intermediate earthquakes in 1983 accompanied with an extension of the surface of the volcano. Based on previous eruptions and indicators, they assumed that magma had intruded into the magma chamber, which made the possibility of an eruption more certain.

A satellite detected the volcano's eruption after discovering an unusual infrared signal from the volcano. The eruption consisted of a lava fountain (seen below), venting at the rifts, the creation of new rifts, and lava flows. The flow was especially dangerous as it advanced towards the town of Hilo, destroying levees meant to check its flow. Luckily the eruption slowed and the lava became stickier, so the town was not damaged; however, it was a reminder of the dangers of living close to an active volcano. Yet, the vog caused by the eruption hung over Hawaii for a while.

Due to the satellite and to the constant monitoring of the volcano, scientists and residents were more prepared for the eruption to occur. In Flagstaff, we aren't as concerned about the hazards our beautiful Peaks and the SFVF pose. This case study illustrates the benefits of monitoring and the unpredictability of volcanoes. Despite the baseline data that scientists had on Mauna Loa, they still could not predict when the volcano would erupt. They could only claim that they thought it would be based on previous behaviour.

Next week we will take a look at another Hawaiian volcano, Kilauea.

An interesting volcanic event this week: Japan's Sakurajima erupted on Sunday (February 7, 2016). The fountain of lava was not just shooting out glowing orange material, but lightning too. It is strangely pretty. To watch a video see http://www.huffingtonpost.com/entry/sakurajima-volcano-lightning_us_56b8016ce4b08069c7a7c782

Chao,
Rachel

Volcano Monitoring Basics-- how we try to unravel explosive mysteries

Welcome back. I do hope that you haven't had any unfortunate run ins with active volcanoes yet. 

As I have buried myself in reviewing relevant literature, I've found the main techniques volcanologists use to monitor active and dormant volcanoes. I am going to share these with you, but you are more than welcome to space out for the next five paragraphs.

Volcanologists use a variety of instruments to monitor volcanoes that are either ground based or space based (satellites).

Most ground based instruments measure ground deformation and seismic activity. Ground deformation is normally measured by two different instruments: a tiltmeter or a Electronic Distance Measurement (EDM). A tiltmeter is a device similar to a carpenter's level that uses a small container filled with a conducting fluid and a bubble to measure the change in slope of the ground. EDMs measure the extension and contraction of the ground using benchmarks that are placed on a volcano to send and receive electromagnetic signals. Both techniques measure the movement of magma under the Earth’s surface.

Seismic waves are measured with, yes, seismometers.From the recorded seismic waves, volcanologists are able to determine the structure and plumbing system of the volcano.

The introduction of satellites into the scientific research is beneficial to the monitoring of volcanoes because it has allowed volcanologists to remotely study volcanoes. Much like ground based techniques, synthetic aperture radar interferometry (InSAR) measures the displacement of a volcano’s surface in terms of magma movement beneath the ground. Satellites also provide photographs of the Earth, which allows scientists to spot ash plumes and changes to the topography of volcanoes. They use radar too as it provides images of the Earth even when it is dark or there is heavy cloud cover.

By analyzing data, volcanologists can attempt to predict eruptions, but they must have a proper amount of baseline data on volcano. When volcanologists have this background knowledge, they are able to discern between the normal workings of a volcano and eruptive behaviour.

However, volcanoes remain mysterious and mischievous because they often give no warning signs that they are about to erupt, or they display eruptive signs and never erupt. This is why it is crucial to make the public aware of the hazards volcanoes pose, even if they are dormant for the time being.

 I also receive updates on active volcanoes. Today, Kilauea (Hawaii), Shishaldin, and Cleveland (Alaska) are all displaying signs of activity. If you would like to receive these daily updates, sign up at: https://volcanoes.usgs.gov/vns/register.php

Have a gneiss day,
Rachel