Geoscience Reports
Winter 1985 No. 5
VOLCANO: THE EARTH POWERFUL
Power fascinates. Whether that power is concentrated in a man or a
machine, we have all stopped in wonder to observe. Probably the most captivating power in
the world, however, is a volcano. This power is neither made by nor controlled by man.
Just what is a volcano? What causes a volcano? Are volcanoes good for man, or must we just
learn to live with them?
The ancient Romans' fascination with the power of fire was deified by
their god Vulcan, who was identified with the Greek god of fire Hephaestus. ''Volcano''
(vulcano) is derived from the Latin word Vulcan.
Technically, a volcano is ''a vent in the surface of the Earth through
which magma (molten rock) and associated gases and ash erupt; also, the form or structure,
usually conical, that is produced by the ejected material" (1). However, for each of
us the word volcano brings to mind a different picture. One may be the fire-pit of
Halemaumau, in Hawaii, another Mount St. Helens in Washington state, or possibly Mt.
Vesuvius in Italy. With over 600 active volcanoes worldwide, the list grows even longer.
If one were to plot on a map (class activity?) the locations of the 600
active volcanoes, the overwhelming majority would fall along the perimeter of the Pacific
Ocean. This belt of volcanoes is formally known as The Ring of Fire.
Three Classes
The Earth's volcanoes, active and extinct, can be divided into the following three major classes:
The land volcanoes can then be further subdivided into six types depending upon the eruption characteristics. They are:
The Icelandic type of eruption is a non-violent effusive eruption
resulting in vast floods of basaltic lava forming large lava plains. It was Icelandic-type
eruptions that formed the Columbia Plateau and Snake River Basalts of the Pacific
Northwest United States.
Hawaiian-type eruptions are relatively non-violent, often resulting in
lava lakes and spectacular fountains. Land forms produced by this type of eruption are
gentle-slope shield volcanoes.
More Violent
Strombolian eruptions (from Stromboli, Italy) are more violent than
Hawaiian eruptions. This type is a spasmodic eruption with events occurring minutes or
hours apart. Masses of lava and ash are periodically thrown into the air. The land forms
produced by this type of eruption are steep-angle slopes composed of alternating layers of
lava and ash.
Vulcanian eruptions (from Vulcano, Italy) are violent and tend to
destroy earlier volcanic structures. Large amounts of ash are produced when the viscous
lava plug found in the neck of the volcano is shattered by the high gas pressure below the
plug. Many eruptions start this way when the blocked vent is initially cleared. Land forms
produced by Vulcanian eruptions are similar to those produced by the Strombolian-type.
Plinian eruptions (from Pliny The Elder) are even more violent than
Vulcanian eruptions. Ash clouds can reach altitudes of several kilometers. It was this
type of eruption that destroyed Pompeii and Herculaneum in A.D.79. Pliny died while
studying this eruption of Vesuvius. The May 18, 1980 eruption of Mount St. Helens would be
classified as this type.
Pelean eruptions (from Pelee, Martinique) are considered the most
violent type of eruptions. This type of eruption not only has the Plinian-type vertical
ash cloud but also the lateral nuees ardentes or swiftly moving, glowing clouds
of ash. (In 1902 St. Pierre in Martinique was destroyed by a nuees ardente.)
Large amounts of ash and pumice are also rapidly ejected during the eruption.
The degree of violence and the type of products produced can be
directly related to the amount of silica (SiO2), water and gases in the lava.
The quiet runny lavas of Hawaii are at the low-water/low-silica end of the spectrum (basic
lavas)-while the explosive Mount St. Helens products are the result of the
high-water/high-silica end (acidic lavas).
Basic lava flows are divided into three types depending upon their flow
characteristics. They are:
Aa-type lava has a rough fragmented surface with a dense interior. Aa lava-flows travel a few meters an hour at most.
Porous Interior
Pahoehoe lava has a smooth glassy surface with a very porous
interior. One of the fastest pahoehoe flows attained the speed of 100 m/sec (over 200
mph!); however, fast flows are normally around 30 m/sec (about 70 mph), with the majority
of flows traveling much slower.
Pahoehoe flows can cool on the outside forming an interior conduit
through which lava continues to flow. When the lava ceases to flow from the source, the
conduit will often continue to drain, leaving a hollow cave-like structure called a lava
tube. Lava tubes can vary in size from a few millimeters-to over ten-meters in diameter,
depending upon the volume and length of flow.
Lava
Pillow lava is the result of lava erupting in a subaqueous
environment. As the name suggests, this lava type assumes the form of sacks or pillows,
caused by rapid water cooling. The pillows are usually heaped one upon another. The
pillows have rounded tops with the bottoms of the pillows adapting the form of its
underlying surface.
The more acidic lavas tend to form pyroclastic material (rock material
formed from volcanic explosion or aerial expulsion from a volcanic vent). These
pyroclastics are classified into at least seven different categories, depending upon their
size and texture. These categories are:
Ash is a fine unconsolidated pyroclastic material with a particle
size of 4 mm or less.
Lapilli are unconsolidated pyroclastic fragments with a size range of
4-64 mm. Cinder and scoria may be the more commonly referred terms of lapilli.
Blocks and bombs have a size range greater than 64 mm. Angular chunks
of old country rock or old lava, ejected as solids, are classified as blocks. Blocks are
not produced from the magma of the same eruption.
Bombs are rounded rocks, initially ejected in the molten state. Bombs
are produced from the magma of the same event although they may have older country rock or
lava in the center. Bombs usually vary from fist size to basketball size, but occasionally
larger ones are noted. The Cotopaxi volcano is said to have thrown a 200 tonne block 14
km!
Rock Foam
Pumice is a light, tan-colored rock foam. The density of pumice is
often less than water, resulting in rock that floats.
The darker, more dense vesicular material thrown from the volcano is
known as cinder or scoria.
Both pumice and scoria can range from ash size to block/bomb size.
A rock derived from ash or lapilli and consolidated by the action of
water, is known as tuff. If the consolidated material is larger than lapilli the rock is
known as tuff breccias. Breccia is a rock consisting of sharp fragments embedded in a
fine-grained matrix.
Occasionally, a dark, silica-rich magma will cool very rapidly and form
a non-crystalline rock known as obsidian, or volcanic glass. Use of the term obsidian goes
back as far as Pliny, in describing rock from Ethiopia.
The questions as to the cause and origin of volcanoes must by their
very nature remain open. As our understanding of the Earth's interior processes increases,
so will our understanding of the causes of volcanoes.
Early man's understanding of volcanoes was directly linked with gods
such as Vulcan and Hephaestus. Legends of fire deities such as "Madam" Pele and
her curses are still adhered to by some, even today! This is evidenced by the display in
the Hawaiian Volcano National Park Center.
The earliest serious attempt dedicated-totally to the study of
volcanoes was made by G. Paulett Scrope in a book entitled, Considerations on Volcanoes,
published in 1852. However, the sustained intensive study of volcanoes did not begin until
after the destruction of St. Pierre, Martinique, in 1902. Since that time the study of
volcanoes has been a multinational effort.
Gas Through Cracks
In 1852, Scrope identified the driving force of volcanoes as gas
attempting to reach the surface of the earth through cracks and fractures in the Earth's
crust.
Since that time modern geology has given answers as to why volcanoes
are distributed in areas such as the "Ring of Fire." That answer is plate
tectonics, a topic to be covered in a later issue of Geoscience Reports.
However, the question as to the driving force of plate tectonics is
still open, as therefore must be the question of what causes a volcano.
While volcanoes can and have caused large-scale destruction and loss of
life, the credit side of the volcano ledger is very full. Without question some of the
most productive and fertile land around the world is volcanic in origin.
Energy utilization is now becoming a big by-product of volcanology. In
Reykjavick, Iceland, over 70% of the population derives its heat and hot water from
geothermal wells. In Larderello, Italy, site of the first geothermal steam field (1904),
geothermal energy produces about 400 mega-watts of electricity. The world's largest
geothermal electrical generating station is found in Geysers, California, with a
production rate greater than 500 mega-watts and growing.
Natural hot springs and spas are also a benefit of volcanoes. The great
scenic wonders of many National Parks are located on volcanic centers, including
Yellowstone National Park in Wyoming.
Truly, volcanoes are a beautiful and fascinating manifestation of the
Earth Powerful!
(1) "Glossary of Geology", 2nd ed., 1980, Falls Church, American Geological Institute.
Further Reading
The following books and articles are intended to assist in further understanding the theme of the feature article ''Volcano: The Earth Powerful.''
For a list of the 100 most notorious volcanoes, please send a self-addressed stamped envelope to: Geoscience Reports: Volcanoes, Geoscience Research Institute, Loma Linda University, Loma Linda, CA 92350.
EDITORIAL
The Earth Series
Unlike the "World Series" which is dedicated to baseball,
the next several issues of Geoscience Reports are going to be dedicated to "The Earth
Series." In addition to "Earthquake" and now "Volcano: The Earth
Powerful," other Earth topics to be covered will include: Plate Tectonics, Glaciers,
Rocks & Minerals, Earth Forms, Ecology and Fossils.
If you have particular questions in any of these areas that you would
like to see covered, or if you know of another 'Earth' topic that you would like to see
discussed, let me know and I'll see what we can do.
A. Y. Honors
With some additional study on your part, you should be able to take this "Earth Series" material and help your students complete the A Y Honors in:
Unlike the "World Series, " which has only one winner, it is the desire of GRI that everyone will be a winner with Geoscience Reports. It is also our desire that not only will you gain a better understanding of the Earth but that you will be able to look beyond the science of the project to the Designer. By seeing the Designer more fully we can enter into a deeper relationship with Him.
p.s. If you have the time, drop us a line and let us know about your How-To adventures!
MOUNT ST. HELENS SLIDES
I have just reviewed a 40-slide, 25-minute cassette program on the
eruption of Mount St. Helens, and I highly recommend it! The program is produced by
Finley-Holiday Film Corp. in Whittier, CA.
The slides are of excellent quality and the narration is well done. A
short general introduction to volcanoes is given before the main topic of Mount St. Helens
is covered.
The slide/cassette program may be obtained by sending $14.95 plus $2.60
(s & h) to:
Finley-Holiday Film Corp.
P.O. Box 619
Whittier, CA 90608
Program #40-85 ''Mt. St. Helens Erupts.'' Mention that you learned about the program from Geoscience Reports!
CHANGE OF PERSONNEL:
July was a busy month at GRI for its personnel. Richard Tkachuck,
left GRI to join the Biology Department at Loma Linda University while James Gibson joined
GRI as Richard's replacement.
James Gibson completed his Bachelor's and Master's degrees in Biology
at Pacific Union College in 1968 and completed his Ph.D., in Biology, at Loma Linda
University in July 1984.
Before starting graduate school at LLU, Jim and his family served four
years in the mission field, where he taught Biology and Mathematics in Sierra Leone,
Africa. Prior to his service in Africa Jim taught Biology and Chemistry at Rio Lindo
Adventist Academy.
A recipient of GRI research grants as a graduate student, Gibson is
presently working with Mammal Speciation and Distribution of Vertebrates in Time and Space
(Past and Present).
Gibson married the former Dorothy White and has two daughters, Deborah,
age 16, and Karina, age 14.
The GRI is pleased to welcome the addition of this competent scientist
to its staff.
GRI ANNOUNCES RESEARCH GRANT AWARDS:
Research grants totalling $11,600 were awarded to 6 individuals for Phase-I, 1985. Each year GRI accepts applications for proposed research centered around creationism. The grants are open to individuals in academic institutions, and the spectrum of possible research areas is quite broad. The award grants represent newly initiated work as well as funding for continuing studies. Research topics funded are:
HPB A Test of the Varve Theory: Green River, WY (LLU) R. Carter Kin Recognition in Peromyscus (WWC) A. Chadwick Paleocurrents in the Geologic Record (SWAC) T. Goodwin/
L. BrandPleistocene-Holocene Sciurid Zoogeographic Change Recorded in Kokoweef Cave (LLU) W. Hughes Chemical Composition of Skeletal Patterns in Brachiopods (AU) R.Tkachuck Automated Cartographic Analysis of Recent and Fossil Mammal Distributions (LLU)
Although the above represents the physical and biological sciences, grant proposals in the history of science, biblical studies or philosophy would also receive consideration. Application DEADLINE is November 15, 1985 for funding by February 1, 1986. Potential applicants should contact C. L. Webster at the GRI for further information.
CALL FOR PAPERS ...
Do you have a restless pencil or a lonely sheet of paper? If so, why
not try your hand at putting the two together and writing a feature article for Geoscience
Reports, or sharing with others your experiences in the How-To Department?!
Feature articles should be 750 to 1,000 words in length. The subject
matter should be on a science topic of general interest to teachers (K-12), with emphasis
on understanding God's created works. A list of further reading should be included with
the feature article, whenever possible.
The How-To Department should be singular in purpose and include concise
directions and illustrations. Topics should be readily adaptable for in-class construction
and/or demonstration.
If feature articles and how-to's are not your strong suit, why not try
an editorial?! Here would be your chance to share with others your concerns.
All submissions are to be typewritten and double-spaced. All authors
should be identified by name, place of employment, grade level, and date, at the end of
the article. Submit all articles and inquiries to:
Editor, Geoscience Reports
Geoscience Research Institute
Loma Linda University
Loma Linda, CA 92350
NEWS NOTES:
GRI Field Conference in Europe
Requests made by the Euro-Africa Division (EUD) of the General
Conference of Seventh-day Adventists over a four-year period came to fruition in a field
conference conducted by the Geoscience Research Institute 4-18 July 1984. The purpose of
this conference was to provide EUD administrators, educators, editors and pastoral
leadership with material that would enable them to relate effectively to scientific
approaches that undermine confidence in the Bible.
The 49 participants in this conference included 10 "guests"
from the Northern European Division (NED). Eighteen countries were represented. By means
of a translator, lectures and discussions were presented in both English and French.
Informal discussions were conducted in English, French, German, Spanish, Portuguese,
Italian, Hungarian, and Yugoslavian, with a few remarks in Swedish, Finnish, Danish, and
Czechoslovakian.
Scientific Issues
Formal presentations on scientific issues were given by Robert
Brown, Harold Coffin, Ariel Roth, and Clyde Webster of GRI, Elbio Pereyra of the Ellen G.
White Estate, Henri Rasolofomasoandro of Seminaire Adventiste du Saleve, and A. E.
Wilder-Smith, who is the most widely known evangelical creationist among European
scientists. The program for each day began with a devotional presented by one of the EUD
or NED participants.
The first five days of the conference were based at Seminar Schloss
Bogenhofen at St. Peter Am Hart in Austria, and included one day of field study in the
Austrian Alps. Two days of travel and field study across Switzerland brought the
conference group to Seminaire Adventiste du Saleve at Collonges-sous-Saleve in France
which served as the base for the remainder of the conference. From Collonges there was one
day of field study in the Jura Mountains, and two days of field study in central
Switzerland that included the Zermatt area.
Transportation was provided by a large tour bus equipped with a public
address system that made travel time useful for mini lectures and discussion sessions.
Besides providing an ideal scenic setting or this conference, the Alps
gave unsurpassed insight into the nature and magnitude of the disruption experienced by
planet Earth during the episode described in Genesis 7 and 8.
Puerto Rican Creation Seminar
A creation seminar was held in Puerto Rico from November 19-24 under
the sponsorship of GRI. The seminar was conducted on the campus of Antillian College in
Mayaguez, and was hosted by Dr. Henry Zuill, chairman of the Biology Department, and Dr.
David Rodriguez, president of the college. Three GRI staff members, Drs. Harold Coffin,
Clyde Webster, and Jim Gibson, were joined by Dr. David Rhys in presenting the seminar,
which was attended by about 50 people.
Located on a hill above the city, with warm tropical breezes, Antillian
College provided a special setting for the seminar, far from the snows which were falling
on the mountains around GRI's headquarters in Loma Linda, California. The group attending
the seminar was composed largely of students and staff members from the college, and
pastors from all parts of the island. Several of those in attendance were from the
Dominican Republic. Most of the people are bilingual, but since Spanish is the principal
language of the island, all lectures were translated into that language. Dr. Rhys had the
advantage of speaking Spanish fluently, so his lectures were translated into English for
the benefit of the other lecturers.
Reception
The week began with a reception on Sunday evening, which allowed the
visitors and hosts to get acquainted. Except for Thursday, when a field trip was
conducted, four lectures were presented each day, with an open discussion period each
afternoon. The high level of interest in the topics discussed was indicated by the number
of questions brought up during discussion periods. Each day, the number of questions was
so large that time ran out before they could all be discussed. Dr. Coffin presented
lectures on the evidences for the Flood and the importance of Creationism to Christians.
Dr. Webster discussed evidence for the age of the earth, including radiometric dating,
uranium deposits, and the use of trace elements. Dr. Gibson spoke on evidences for changes
in species and how these relate to the Biblical record. The increasing interest in GRI's
Spanish publication, Ciencia de los Origenes, was described by Dr. Rhys, who also
presented slides of Saturn and Jupiter, taken by NASA's Voyager I and II space probes.
On Thursday, the group went on an all-day field trip. At 8:30 a.m.,
about 35 people piled onto a big yellow school bus for the trip. Stops were made to
observe some of the geologic features of the island, such as marine fossils in a road cut,
layers of turbidites, and deposits of conglomerates in the mountains. Limestone mountains,
in some places eroded to form a karst topography, were evidences of the magnitude of
geologic forces acting during the island's past. In addition to the magnificent scenery on
the trip over the mountains, those sitting near the windows of the bus will remember how
narrow the road was and how frequently the bus seemed to be too large to make the sharp
turns on narrow bridges spanning deep chasms. By 7:30 that evening the group was back at
the college, ready for a good rest.
Sabbath
On Sabbath, Dr. Coffin gave the sermon for the church at Belle Vista Hospital, located on a hill perhaps two or three miles across the valley from Antillian College. Meanwhile, Dr. Rhys spoke at Antillian College. Sabbath afternoon a discussion period was held at Antillian College, giving opportunity for questions to be asked by those who had been unable to attend during the week. For those able to be present, the Creation Seminar was a success in helping to harmonize the story of the earth as revealed both in nature and in scripture.
Science Council
The Biblical Research Institute Science Council of the General
Conference of Seventh-day Adventists met this past August in Hawaii. The exotic islands of
Hawaii were selected because they are a prime area for the study of biological speciation.
Hawaii also has an extremely high degree of endemism especially among the plants, snails,
and birds.
Participants included the science staff of the Geoscience Research
Institute, a dozen other members of the Science Council, and other scholars specializing
in speciation. A highlight of the trip was a behind-the-scenes tour guided by the staff of
the Bishop Museum in Honolulu where the participants observed variation within the
honeycreeper bird group. Several species are now extinct. Study was also given to recent
volcanism and the contrast between slow and rapid rates of recovery of vegetation over
volcanic flows depending on extenuating circumstances. A number of study papers especially
dealing with questions of speciation were presented and discussed.
For future meetings the committee voted to give special study to the
relation of plate tectonics to flood models, and also to the nature of inspiration.
HOW-TO DEPARTMENT . . .
Volcano In A Can
All of the fury, power, and excitement of a miniature volcano can be
safely controlled in your classroom.
Construct a simple papier-mache volcano cone with a small shallow tin
can firmly anchored in the top, as shown in Fig. 1. Allow the papier-mache to dry, then
paint the volcano grey with red rivers of lava flowing down the sides. After the paint has
dried, cover the volcano with two coats of "Hot Airplane Dope" in order to seal
the papier-mache and paint.
MATERIALS LIST
Purchase from Carolina Biological Supply Company, or a similar
supply house, a few ounces of granular Ammonium Dichromate, (CBSC catalog # 84-3908).
Place two tablespoons (DO NOT USE MORE!!) of the Ammonium Dichromate in
a little pile, in the volcano's tin can. The volcano is activated by placing a lighted
fireplace match into the top of the Ammonium Dichromate. Once the Ammonium Dichromate
starts to react, the match may be removed, as the reaction is self-sustaining. Step back
and enjoy the volcano and the delight of your students!
This exothermic (heat releasing) reaction does not produce any harmful
gases or other by-products. The green powder does need to be cleaned up carefully as it
can cause a mess. For those of you who are interested, the chemical reaction is:
(NH4)2Cr2O7 (s) = N2 (g) + 4H2O (g) + Cr2O3 (s) + Heat.
You may desire to turn off the lights after the volcano has been activated and watch the ''lava'' shoot up and out of your volcano! Or you may even want to take a photograph for your bulletin board!
Geoscience Reports Winter 1985 No. 5
Editor Clyde L. Webster
Associate Editor Katherine Ching
Subscription requests, correspondence, and notices of change of address should be sent to: Geoscience Reports, Geoscience Research Institute, Loma Linda University, Loma Linda, CA 92350.
Geoscience Reports is a newsletter published by the Geoscience Research Institute to present current happenings at the Institute as well as articles of general interest which deal with creation/evolution issues for primary and secondary school teachers. The views expressed are those of the authors and not necessarily those of the Institute.
Staff of the Institute are: Ariel A. Roth - Director, Robert H. Brown, Katherine Ching, Harold G. Coffin, L. Jim Gibson, and Clyde L. Webster.