Volcanology
GEOL 405/505
Fall 2008
“No Apparent Danger” by Victoria Bruce
Reading Assignment #3
Answer the questions (typed) and be able to discuss the following chapters on Tuesday, October 21
Chapter 7 – Urcunina, the Fire Mountain
1. Has Galeras had a previous history of eruption? Yes, observations back to 1830’s every set of o
bservations indicated that caldera was changing (and erupting between observations). 1936, small
column collapse. Police at summit had never seen an eruption in their lives.
2. How was the first warning of Galeras activity handled differently than Nevado Del Ruiz?, wisps of
steam
3. In April 1988, Fernando Muñoz (a geophysics professor at the National Institute of Geology)
observed, first-hand, the new activity of Galeras. What did he observe? Glowing crater
4. After making his observations, Muñoz requested assistance from whom? Dave Harlow and Norm
Banks (USGS)
5. What else did Muñoz do? Wrote a letter to the president
6. What was Harlow’s first impression of the seriousness of the situation when he arrived in Pasto? EQ
data- not a big deal
7. What did Harlow think when he was taken to see the crater? The situtation was serious.
1.
2.
From section below Who is Bernard Chouet? Swiss usgs seismologist, who using his discovery of
long-period earthquakes accurately predicted eruptions in Alaska at Redoubt Volcano
What are tornillos? Spanish for screw- the shape of long period earthquakes.
Chapter 8 – Dissecting Galeras
3. Who is the organizer of the meeting and what is his relationship with Marta Calvache? Stanley
Williams, now at ASU.
4. What meeting was going to take place in Pasto beginning January 11, 1993? Intl workshop for
Volcan Galeras (UN Natur disast reduction- DECADE volcano)
5. What was the relationship between the Swiss volcanologist, Bruno Martinelli and Calvache? couple
6. What was the reaction of the Columbian military when Calvache and Martinelli wanted to dynamite a
portion of the route down into the Galeras crater? No way
7. Had Stanely Williams remained active in the study of Columbian volcanoes since the 1985 eruption
of Ruiz? yes
8. Why did Calvache change the day of the conference field trips? Brown out in pasto
9. What does “decade volcano” mean? Focus on reducing hazards
10. Describe the argument between French volcanologists Haroun Tazieff and Robert Brousee about the
Soufriere Volcano on the island of Guadeloupe? Tazieff predicted no eruption Brouse predicted a big
eruption- both went straight to the press.
11. What did Andy Adams observe about Stan Williams preparation for the field trip into the crater on
Thursday? Not a focus on safety
12. Who is Bernard Chouet? Swiss usgs seismologist
13. What are tornillos? Long period earthquakes
14. Was Stan Williams concerned about the Tornillos?
Chapter 9 – To the Mountain
Based on Bruce’s account, describe both the pros and the cons with respect to the safety precautions and
emergency response plan that Stanley Williams and others had in place for the field trip into the Galeras
crater.
Pros- none
Cons- everything. No hard hats, no discussion of precautions or a response plan
Read the following chapters and answer the following questions, typed, for Thursday, October 30th
Chapter 10 – The Descent into Galeras
Chapter 11 – The Eruption
Chapter 12 – The Rescue
1.
Based on Bruce’s account, describe both the pros and the cons with respect to the safety precautions
and emergency response plan that Stanley Williams and others had in place for the field trip into the
Galeras crater.
2.
How much time had passed between the warning from Pasto that a tornillo event had occurred and
Williams’ first suggestion that some of the scientists should start heading back? 945- tornillo ,
12:45
a. How much time had passed before Williams and others decided to leave? 1:30
b. Were there other scientists still working when Williams was descending the cone? Yes
3.
Estimate the VEI of this eruption based on the height and dispersal of ejected material. What type of
eruption would you call it? 2, vulcanian
4.
After the initial eruption, what specific type of volcanic activity were the scientists (in the crater and
on field trips on the flanks of the volcano) most worried about? Pyroclastic flow
5.
Who were the first people into the crater to rescue the survivors? And approximately how much time
had passed since the eruption?
Read the rest of the book and be prepared to discuss it on Thursday, November 13
Chapter 13 – The Aftermath
Chapter 14 – Conflicting Accounts
Epilogue: Winter 1996-Summer 2000
Study the following thought questions. You will not have to turn in the answers to these questions but you
should study them for the exam.
o What caused the fatal eruption according to Luis Ruales (a hotel bellhop) and most of the other
citizens of Pasto (Pastusos)?
o After the disaster, Andy Adams (Los Alamos National Lab) inspected the seismic records and
reviewed the earlier predictions of Galeras activity. What did he find?
o How many days passed after the fatal eruption before scientists entered the crater? What types of
safety precautions did they take?
o What were some of the things that Stanley Williams told the news media that were upsetting to the
other field trip participants and inaccurate (according to Bruce)?
o Based on the account of Victoria Bruce, was Stanley Williams responsible for the deaths of his
colleagues? Was he aware of the seismic activity (tornillos), their meaning and all of the potential
dangers before leading the trip into the crater?