New GIS class

I started a new GIS (Geographic Information Systems) class from ESRI today: Learning ArcGIS Spatial Analyst. I am taking courses like this to expand and update my GIS skills. Plus, it is cool stuff to work with.

I’ve done some of this before, such as generating shaded relief and contours:

Shaded relief and contour maps of Mt. Shasta, California. Note the lava flows on the lower slopes north of the main part of the volcano. Taken from the ESRI course Learning ArcGIS Spatial Analyst.
Shaded relief and contour maps of Mt. Shasta, California. Note the lava flows on the lower slopes north of the main part of the volcano. Taken from the ESRI course Learning ArcGIS Spatial Analyst.

Other things will be new to me, such as interpolating data. An example of this would be filling in precipitation values between scattered weather stations.

I might not get much blogging done this week, as I’d like to really push myself to get this done.

Grace and Peace


Here’s my first hillshade map for this class. This is a hilly region near Harlan, Kentucky, showing the topography with the sun at an elevation of 45 degrees in the northwest:


Here is a slope percent map of the same area. Green areas are flat, red areas are steep, and yellow areas are of intermediate slope:


Here’s one more for tonight. This map shows slope aspect, which is the direction the slope faces:



You could combine the final two maps to search for a homesite on a shady north-facing slope; not too steep, and not in the flats.

All of this illustrates one of the strengths of GIS: the ability to quickly analyze a large geospatial dataset—in this case a digital elevation model—to create new output files.

The Earth has a future

This item was originally posted in June 2006. I have added it to my blog recycling program. Because I have new readers of The GeoChristian, I will occasionally go back and re-use some of my favorite blog entries (with some editing).

Additionally, this is being submitted to the January 2009 Accretionary Wedge Geoscience Blog Carnival, in which a number of geology bloggers are writing on the topic of speculation about future Earth history from a geological perspective. The first part of this post contains no original thinking on my part, but is a summary of an article that appeared in the online journal Geosphere.

For those of you who have gotten here who are not regular readers of The GeoChristian, welcome. I write primarily for a general audience rather than for a geological audience. One of the primary objectives of The GeoChristian is to promote geoscience literacy in the Evangelical Christian community, and so I have a number of posts on issues that are controversial within that group, including the age of the Earth and Christian attitudes toward the environment.

I close this post with a few thoughts on Christian perspectives on the future of the Earth.

The Accretionary Wedge #16: Pondering the geological future of Earth is now posted.

We usually think of the science of geology as being about the past: geologists often reconstruct events that happened thousands, millions, or even billions of years in the past. Sometimes geologists are called upon to project into the future as well. Examples of this include earthquake prediction and finding sites for long-term (>10,000 years) storage of radioactive waste. Geologist Steven Ian Dutch takes a look at the prospects for the next million years in “The Earth Has a Future”, published by the Geological Society of America in the online journal Geosphere. I’ll summarize the article and then give a little commentary on it.

The article is available online in two versions:

Dutch starts with processes active on the surface of the earth—erosion, uplift, volcanic activity, plate movement, changes due to human activities—as well as the more rare events such as eruptions of supervolcanoes and meteorite impacts. He calculates the rates at which these occur at various places on the earth, and makes predictions as to what the earth will be like in one thousand, ten thousand, one hundred thousand, and a million years from now. He acknowledges that there are many uncertainties in these speculations, but it is still a worthwhile exercise.

One of the most difficult things to predict, in Dutch’s mind, is the future impact of human activity. Will humans become extinct? Will technological civilization collapse? Will humans modify the surface of the earth beyond recognition?

Some things that will happen in the next 1000 years:

  • 5-7 magnitude 8 earthquakes along the San Andreas Fault, with total movement of about 25 m.
  • 40 eruptions of Vesuvius
  • 5-10 eruptions of Fuji
  • ~12 eruptions of Cascade Range volcanoes
  • Perhaps smaller volcanic eruptions in areas with lower-frequency eruptive histories: cinder cones in the SW United States, Puy region of France, or Eifel region of Germany
  • 200 eruptions of Mauna Loa on Hawaii, building it 5 m higher
  • Probable death of Old Faithful Geyser, as its geothermal plumbing shifts over time
  • Several world-wide large volcanic eruptions (on the scale of the 1815 eruption of Tambora in Indonesia, which caused “the year without summer” in the United States and Europe)
  • Little change visible in mountain ranges as they simultaneously uplift and erode
  • The Mississippi River and its delta will change its course. Its delta naturally changes position every 1000 years or so, and is overdue (thanks to the Army Corps of Engineers)
  • Niagara Falls will have cut back 900 m upstream from its present position
  • A good chance of a meteorite impact with a crater of 100 m or more
  • Most steel structures (Eiffel Tower, Golden Gate Bridge) will survive only with careful maintenance
  • Humans will still be using coal and natural gas, but not much petroleum

Some things that will happen in the next 10,000 years:

  • 50-70 magnitude 8 earthquakes on the San Andreas Fault, with displacement of 250 m
  • Kilauea, on Hawaii, will be about 100 m higher
  • Several hundred eruptions of Vesuvius
  • 100 eruptions of Fuji
  • 100 eruptions of Cascade Range volcanoes
  • 90 m uplift of the Baltic Sea and 100 m uplift of Hudson Bay as they continue to rebound after the removal of Pleistocene ice sheets. These bodies of water will, therefore, be smaller
  • By natural cycles, we would be nearing the end of the present interglacial, looking to the beginning of a new ice age
  • Niagara Falls will retreat upstream by 9 km
  • Higher probability of a 1 km crater formed by meteor impact, with considerable destruction up to hundreds of km away
  • Without considerable care, the only human structures that will still exist are large highway cuts and large monuments
  • No present human cities are 10,000 years old. Will any of our present cities exist 10,000 years from now?

Some things that will happen in the next 100,000 years:

  • 2.5 km slip along the San Andreas Fault. Not enough to close the Golden Gate
  • Kilauea will be 1 km higher, and Loihi (an underwater volcano SE of the island of Hawaii) will be above sea level
  • Some mountain ranges will have had 1 km of uplift. In most cases, this will be accompanied by close to 1 km of erosion, so the net result will be exposure of deeper rocks, not higher mountain ranges
  • Earth could be in an ice age
  • Niagara Falls will stop retreating as rock types are different further upstream. A new waterfall will start forming near the outlet of Lake Erie
  • There could be a meteor impact with global effect

Some things that will happen in the next 1,000,000 years:

  • The San Andreas Fault will have slipped 25 km, perhaps blocking the entrance to San Francisco Bay
  • The highest points of the island of Hawaii will be Kilauea and Loihi. Mauna Loa and Mauna Kea will be old and eroded
  • Several enormous catastrophic landslides will have occurred on the slopes of Hawaii
  • Many current volcanoes will have become extinct, being replaced by others
  • One or more eruptions of “supervolcanoes” such as Yellowstone or Long Valley, California. (The last large eruption at Yellowstone, 640,000 years ago, had a volume of 1000 km3, as compared to 0.5 km3 for Mount St. Helens 1980)
  • Some rivers will have changed their courses
  • Ten or more major periods of glaciation
  • Hundreds of meteor impacts
  • The earth’s day will be 20 seconds longer (due to tidal effects)
  • The moon will be 38 km further away
  • The solar system will have traveled 750 light years in its orbit around the center of the galaxy
  • The only present human structures to survive will be large and made of earth and stone: open-pit mines, large road cuts, mine waste piles, the Pyramids. (Even the Pyramids might not make it if the climate becomes more humid in that area).


This kind of reasoning is increasingly important in the Earth sciences: trying to figure out what has happened in the past and what is going on at the present in order to make predictions about what is likely to happen in the future.

Some issues that come to mind as I as a Christian geologist think about the future of the Earth:

  • This paper puts our human achievements in a good perspective. All that we create is of a very temporary nature. Compared to the universe and the potential vastness of time, we are rather temporary. The purpose of this isn’t to magnify the creation, but to magnify the Creator. God is to the universe as the universe is to us. And that is an understatement.
  • In Christian understanding, God is sovereign over the events of the future. This does not rule out the type of investigation that has been done here—we can seek to understand how the earth works and then project that into the future. This is the geological principle of uniformitarianism properly applied to the future. It has its limits, but it can also be a powerful tool.
  • As a Christian, I believe that Jesus Christ, who ascended to heaven after his resurrection, will return to Earth some day. I don’t know when that will be. First century believers thought that it would occur in their lifetimes, and probably couldn’t imagine a delay of at least 2000 years. I don’t know if Christ’s return will be tomorrow, or 3000 years further down the road. I am just told to always be ready.
  • One reason that we need to use our natural resources wisely is what I just stated. We don’t know the future; we don’t know when Christ is returning. Our water, mineral, soil, and energy resources may need to last us a very long time. There are a number of other reasons, of course, for us to pursue a sustainable future.
  • The Biblical view of eternal life (yes, as a Christian I believe in life after death) is not living in heaven. The Earth has a future, at least as a new Earth (Revelation 21:1). Biblical scholars disagree as to the exact relationship between the present Earth and the New Earth; whether it is just a makeover or a complete re-creation. But eternity for the believer will not be spent strumming harps on clouds, but on a real, physical Earth that is in many ways like the one we live on. It will have rocks and trees and bodies of water. It may be different in some ways than the present Earth, but it will still be “earthy.” The primary difference will be the removal of sin and its effects, such as disease, war, famine, and death.
  • Will the new Earth have volcanoes? Earthquakes? Uplift and erosion? Plate tectonics? I don’t know for sure, but I suspect it will. We tend to think of things like volcanoes and earthquakes as “bad,” but I believe these things could fit under the phrase “it was good” from Genesis 1. Volcanoes, for example, renew the surface of the earth, and provide us with rich soils. “Good” isn’t the same as “safe;” in fact, dangerous things have a way of showing God’s glory to us.

Grace and Peace

All truth is God’s truth

Does the Bible take priority over science, or are science and scripture complementary?

Here’s the approach I take: All truth is God’s truth.

I’m not the first to use this phrase by any means, but I think it is a good summary of how I view the relationship between science and my Christian faith.

Sometimes there appears to be a contradiction between science (general revelation) and the Bible (special revelation). When this conflict occurs, it could be for one of two reasons: either we don’t understand nature correctly, or we don’t understand the Bible correctly. In the end, when we understand both correctly, there will be no conflict.

For now, we need to approach these “conflicts” with humility, hard work, and intellectual rigor.

Grace and Peace

Darwin, evolution, and God

charles_darwin_aged_51This may be new to some of you, but Charles Darwin did not reject God because of evolution, but because of other factors, such as anger over the death of his 10-year old daughter. Darwin was more of an agnostic than an atheist, and he certainly was no anti-God crusader like Richard Dawkins is today.

Dinesh D’Souza writes about this at The Evolution of Darwin.

The story is told in Adrian Desmond and James Moore’s authoritative biography, Darwin: The Life of a Tormented Evolutionist. When Darwin’s daughter Annie died at age 10, Darwin came to hate the God he blamed for this. This was in 1851, eight years before Darwin released Origin of Species.

Around the time of Annie’s death, Darwin also wrote that if Christianity were true, then it would follow that his grandfather Erasmus Darwin and many of his closest family friends would be in hell. Darwin found this utterly unacceptable, given that these men were wise and kind and generous. Darwin’s rejection of God was less an act of unbelief than a rebellion against the kind of God posited by Christianity. A God who would allow a young girl to die and good people to go to hell was not anyone whom Darwin wanted to worship.

When Darwin published his work on evolution, the American biologist Asa Gray wrote Darwin to say that his book had shown God’s ingenious way of ensuring the unity and diversity of life. From Gray’s point of view, Darwin had deepened man’s understanding of divine teleology. Darwin praised Gray for seeing a point that no one else had noticed. In later editions of his books, Darwin went out of his way to cite the English writer Charles Kingsley, who described evolution as compatible with religious belief. To the end of his life, Darwin insisted that one could be “an ardent theist and an evolutionist.”

D’Souza (author of What’s So Great About Christianity) concludes with:

This history is important because we can embrace Darwin’s account of evolution without embracing his metaphysical naturalism and unbelief. Dawkins and others like him are in a way confusing the two faces of Charles Darwin. They are under the illusion that to be an evolutionist is essentially to be an atheist. Darwin, to his credit, rejected the equation of these two stances as illogical, even if he didn’t always maintain, within his own life, a clear distinction between his science and his animus toward God.

Charles Darwin was born on the same day as Abraham Lincoln, February 12, 1809. The 200-year anniversary of their births is coming up next month.

Grace and Peace


As you know, this is a difficult time to find a job.

I just sent off application #212. I spent a good portion of the day writing essays on four federal job applications that were due by midnight Eastern time; I sent the last one off at 11:58. I’ve been very well qualified for most of the 212 jobs I’ve applied for. I suppose there are a few that I’m not fully qualified for, and a few that I’m overqualified for.

When I picked up my daughter from school a few days ago, she asked me, “Did you find a job?” My answer was, “I’ve found lots of jobs; they just haven’t found me yet.” There are still companies and agencies hiring, and I’m praying that some day soon one of them will find me.

Remember to reach out to those in your church and community who are without jobs. I am still filled with hope. Some others are having a very difficult time.

Though the fig tree should not blossom,
nor fruit be on the vines,
the produce of the olive fail
and the fields yield no food,
the flock be cut off from the fold
and there be no herd in the stalls,
yet I will rejoice in the Lord;
I will take joy in the God of my salvation.
–Habakkuk 3:17-18 (ESV)

Grace and Peace