Monthly Archives: July 2018

Excavation Rate of the Grand Canyon

In March, I went over the US on a holiday. One of the places we visited was the Grand Canyon. Like most, I was amazed at the size and depth of it. However, I’m a mining engineer who designs big holes for a living, so I was interested to know how the river excavated it, so I had at look at the information they had posted around. Two things struck me:

  1. The Grand Canyon is only about six million years old.
  2. The flow rate of the Colorado river hasn’t significantly changed in that time.

This set me thinking – if it’s only 6 million years old, and the river hasn’t significantly changed in that time, then how did the river manage to carve out the canyon, that seems like a lot of dirt to move per year. So like a good engineer, I thought I’d calculate it:

Volume of the Grand Canyon – 4.17E+12 m3

Years to excavate – 6,000,000

Excavation rate per year – 695,000 m3/year

Excavation rate per second – 0.53 m3/second

Half a cube per second sounded achievable, though possibly more dirt than a river might be capable of carrying. So I looked up the sediment carrying capability of water, and while it’s on the high side, definitely within the capability.

Half a cubic metre of dirt per second isn’t particularly high when compared to a lot of earth moving equipment these days, but when done every single second for the last 6 million years, it adds up to something amazing.

Volume Flowrate
4.17E+12 Volume of the GC
         695,000 cubes per year
             1,904 cubes per hour
                0.53 cubes per second 500 m3/s
                1.32 tonnes per second 500 tonnes per second

WordPress Twenty Seventeen – Four-Column Footer

One of the trickiest things I found to do with the WordPress Twenty Seventeen theme was to try and have a four-column footer.  I found a couple of plugins to do the job, but they either didn’t work, or they were far too complex. In the end, I found an easy solution put a basic HTML table into a ‘custom html’ widget inside of ‘Footer 1’. To do this:

Admin > Appearance > Widgets. The drag ‘Custom HTML’ to the ‘Footer 1’ widget.

The base HTML code for a four column table is:

<table id="logo-table" style="width:100%">

<th style="text-align: center; width:25%;">Heading One</th>
<th style="text-align: center; width:25%;">Heading Two</th> 
<th style="text-align: center; width:25%;">Heading Three</th> 
<th style="text-align: center; width:25%;">Heading Four</th>

<td style="text-align: center;">Item One</td>
<td style="text-align: center;">Item Two</td> 
<td style="text-align: center;">Item Three</td> 
<td style="text-align: center;">Item Four</td>


This did 90% of the job. There was just one other thing I wanted to do: Make the footer full-width. By default, Twenty Seventeen has two half-width footers. I also went in and changed the css so that the footer was full-width.

Admin > Appearance > Customize > Additional CSS

Add in the following code:

.site-footer .widget-column.footer-widget-1
width: 100%;

.site-footer .widget-column.footer-widget-2
width: 100%;

The end result:


WordPress Twenty Seventeen – Change footer colours

To change the footer colours using the Twenty Seventeen theme in WordPress; go to:

Admin > Appearance > Customize > Additional CSS

Add in the following code:

.site-footer { background: #2000a1; }

.site-footer {
    color: #ffffff;

.site-footer a {
     color: #ffffff;

.site-footer a:hover {
     color: #ffffff;

The #ffffff is white, and #2000a1 is a blue colour. The output should look like this:

WordPress Twenty Seventeen – Change uppercase title

I’ve recently been modifying the website for the church I used to attend when I lived in Blackwater –

The main thing I did was change the theme from the old ‘Pinboard’ theme to the newer ‘Twenty Seventeen’ them. It’s a fantastic theme that I was able to do a lot of things with. There were a few things that I had to figure out how to do. The next couple of posts will be a few short ones so I can document the changes I made.

The most annoying thing with the new theme was the uppercase title on the homepage. To change this – go to ‘Admin > Appearance > Editor’ then select ‘Stylesheet’ ‘style.css’. Then scroll down to line 1580. The ‘site-title’ section should look like this:

.site-title {
clear: none;
font-size: 24px;
font-size: 1.5rem;
font-weight: 800;
line-height: 1.25;
letter-spacing: 0.08em;
margin: 0;
padding: 0;
/* text-transform: uppercase; */ <--- add in these comments

As I’ve marked above, comment out the ‘text-transform: uppercase;’ part to remove the uppercase font on the title.

As you can see from the picture below, it works well!


Tiny-Tiny RSS – additional packages needed

I run Tiny-Tiny-RSS as my Google Reader replacement. It’s fantastic. However, now I’ve moved to a VDS, and I needed to install some additional packages. These weren’t listed on the TTRSS install site, so I’ve listed them here, so I can find them again in the future.