The Last on Those Lines (Maybe)

The USGS responded to my inquiry about the strange lines or terracing on some of the hills around Dave’s Home. When the e-mail popped up in my inbox I dropped everything to read it. Apparently my question had been routed to a local office. I read the end first to see who it was from. The closing sounded impressive enough:

       Cartographer

       Western Region GIO

       NSN-SILS
       US Geological Survey
       Menlo Park, California

Then I read the body. “Believe it or not they are most likely caused by cows. Animals tend to want to walk at the same elevation all the time. Humans tend to like to go up and down.”

Lines on the Hills

It’s been a little over one month since I posted the kid’s question about horizontal lines on the rolling hills surrounding Dave’s Home. In my opinion this question is still unresolved, and interestingly the topic is dominating recent ShoutBox posts.  (Click HERE to view the first post on this topic.)

My dad, Tioga-George, seems to believe that these lines are created by livestock. He sent me THIS LINK a few weeks ago. Quite a few other readers believe this, also. I am skeptical, though, because most of the lines are just too perfectly spaced and I don’t ever see the animals following one another in a single file.  Most of the time they are spread out grazing all over the place.

The other contending answer relates these lines with erosion. One of my colleagues at work believes this, too. He claims that certain soils have compression qualities that, when on a hillside subject to gravity and moisture, cause a “slumping” effect based on the slope’s angle of repose. If I understand him correctly, he basically thinks that these lines are caused by mini landslides. I am skeptical of this, also, because it seems to me that if this were the case then the spacing between these lines would change depending upon the steepness of the slope. However, from what I can see the spacing between these lines remains fairly constant all over a given hill.

Stray answers suggest these lines are the result of “contour farming” many years ago and since abandoned, or that they were caused by retreating glaciers, or by the ocean way back when this part of the country was under the sea.

Frustrated by the lack of a definitive answer, about a week ago I wrote three e-mails to folks that I hoped could shed a little light on our mysterious lines. Two e-mails went to the cities nearest these hills. The third went to the company that I believe owns the land itself. Unfortunately none have responded. I will let you know if and when they do.

The one thing I haven’t done is actually walk on these slopes. When the weather was accommodating (which it hasn’t been lately) I would look for openings in the barbed wire fences while driving by. None were apparent. One time I stopped along the side of the road for a closer look. The lines were definitely terraces in the land. The one new thing I noticed was that they are not all parallel. Some lines appear to merge with the one above or below it.

Kid Question #3 - Is Mt. Diablo a Volcano?

Dave’s Home sits in the shadow of a 4,000 foot high mountain called Mount Diablo. As I wrote in a previous post, the kids and I have camped on this mountain before. The kids want to know if the mountain is a volcano, and if it is, could it erupt again?

If you think you know the answer to these questions, please let us know, OK?

Also, we have received another possible explanation for the last Kid Question about the lines circling some of the rolling hills around Dave’s Home. A reader submitted that they may have been caused by contour farming by humans many years ago. (Click HERE to read more about this question.)

Lines in Hills Kid Question

We received many responses from readers explaining what they thought the horizontal lines circling many of the rolling hills around Dave’s Home are.

One reader believes these are ridges created by mother nature to keep the ground from eroding when it rains. Another says these lines may have been created way back when this part of the earth was under an ocean, or perhaps by retreating glaciers. Still another thinks these lines are created by tractors as they till under the weeds every year.

Most responding readers, however, thought that these lines are created by animals, probably cows, as they graze the hillsides. Apparently cows like to follow one another and wear a path into the hills. I find this the most plausible explanation, too. However, I can’t get over how well spaced these paths are.

Thanks again, everyone, for offering your “two cents” on this question from the kids!

Kid Question #2 -- What are the Little Lines in the Hills?

If you look closely at many of the hills, at least those around Dave’s Home, you will see thin horizontal lines circling them, even on very steep sections. Did humans make these lines, or did animals or some other form of nature make these lines?

If you know the answer to this question, please send Dave an e-mail or post a comment in the ShoutBox below. Thanks!

Click HERE to see the post about the answers we received to this question.

Titanic Kid Question

Big thanks to the two readers, Diugo and Tioga-George, who responded to H’s question about the Titanic. The question was would the ship have sunk if it had hit the iceberg head-on instead of scraping it along the side. The answer seems to be that it probably would not have sunk, although we will never know for sure.

The Titanic was designed with 16 water-tight compartments. However, the bulkheads separating these compartments only extended up to decks E or D, and were open at the top. Because of this open-top design, if more than four compartments in the front of the ship flooded, its nose would tilt down because of the weight and allow the seawater to spill over the tops of these bulkheads into the other compartments. When the Titanic side-swiped the iceberg, its hull was breached in five compartments – which was one too many.

If the Titanic had struck the iceberg head-on, there would have been much more initial damage to the ship. The nose and first two compartments may have been obliterated. However, a ships nose is generally its strongest part, designed to withstand a collision without sinking. In addition, the Titanic would not have tilted down enough to allow seawater to spill over the other bulkheads with only two, three or even four compartments breached.

I will try to explain this to H. I’m sure he will be very appreciative!

Kid Questions

I am starting a new topic thread called “Kid Questions”. The kids often ask me amusing and very thoughtful questions, some of which are not that easy for me to answer. For more technical questions I usually look the answer up on the web. (What did we ever do without Google and Wikipedia?) But from now on when this happens I will write a post about their question in the hope that readers will try to answer it. In this way maybe I'll be able to get the kids a little involved in some of the posts, too.

This first question came up about a week ago after the kids and I watched most of the movie “Titanic”. (I skipped over a few kid-unfriendly parts.) Anyway, H asked me if the ship would have sunk if it had hit the iceberg head-on instead of scraping it along the side. This blew me away! This from a kid who doesn’t yet know his times tables!

I am purposely avoiding looking this up on the web to see what the readers of Dave’s Home have to say about this surprisingly insightful question.