Crabs in the sand

This past Memorial weekend, my wife and I remembered, and are thankful for all of the men and women that have given the ultimate sacrifice for our country. We also thank all the current men and women in the military for their service.

As do millions of other Americans, we also celebrated the unofficial first day of summer by traveling to Galveston for a beach day.  It was a hot and sunny day that was a welcomed contrast from all the extreme storms and flooding that has been occurring in southeast Texas.  We walked onto the beach and set up our chair and beach towel close to the sea wall behind a row of chairs and umbrellas that you need to pay for. We apparently picked a wonderful spot, because soon after I sat down, I noticed multiple holes in the sand that I immediately identified as burrows! I was sitting in the chair reading a book while I unknowingly was becoming sunburnt, when my wife said: "look, there is a crab coming out of the hole."  I immediately looked, however, the fast crab quickly jumped back into the burrow. My wife took our camera and waited patiently until she took a picture of the crab that came out of the burrow.

A crab on a sandy beach that is half way in their burrow.

Based on some basic Googling, this type of crab is commonly called a sand crab. In particular, this crab I believe belongs to the family Ocypodidae, a type of semiterrestrial crab that includes the ghost crab and the fiddler crab. Based on viewing images, it appears that this is likely a ghost crab because the male fiddler crab contains a large claw, which I did not see in any of these crabs. If based on the pictures I am mistaken about the identity of these crabs, please let me know and I will change my identification.

A smaller ghost crab in their burrow. The crabs color very closely matches the color of the sand, presumably to avoid predators. 

I wish I had a shovel at the beach because I would have loved to have excavated the burrow to see how deep the burrow went as well as the shape. When I did a Google search for ghost crab burrows I found a couple websites about these crabs. To summarize, ghost crabs belong to the genus Ocypoda. They can be located all around the world on sandy beaches in tropical and sub-tropical coasts. The ghost crab dig burrows to keep cool during the daytime. The burrows typically enter the substrate at a 45-degree angle and can reach a depth of to 4 ft according to the one website (which I will list below). Adult crabs typically have two entrance shafts. Interesting facts I read include that males tend to neatly pile the excavated sand next to the entrance, while females tend to scatter the sand all over. I am not sure what is considered "neat," so I am not sure if I would call the crabs in the above images female or male. Another interesting fact is that younger crabs tend to dig burrows closer to the water whereas older crabs tend to have burrows further away from the water.

While I was sitting at the beach looking at the crabs and their burrows, I did notice that there were balls of sand by the entrance of the burrows. As I continued to watch I saw a crab appear, and throw one of these balls away. I think I was watching a crab currently excavate a burrow. I started to notice that all the crabs were appearing and throwing these balls of sand away from the entrance! Just an interesting note, I also noticed that these balls of sand were wet, indicating that the crab had likely reached the water underneath the sand. Below I will show a video that my wife took of the crab throwing the ball of sand that it excavated.

Here are the websites I looked at for information regarding the ghost crab

https://en.wikipedia.org/wiki/Ghost_crab
http://www.animalspot.net/ghost-crab-sand-crab.html

What do geoscience graduates value most from their academic experiences?

Yesterday I received an e-mail that the new issue of GSA Today was available for download. For those who might not know, GSA Today is a publication of the Geological Society of America. This publication normally has articles about upcoming meetings, job postings, and scientific articles. One of the articles was entitled "Looking back: What do geoscience graduates value most from their academic experiences?" It is a very interesting read, although the results are only from alumni that attended Dartmouth College.

To quickly summarize, the authors found that independent research, field training, and writing were the components geoscientists valued most in their education. To me, this is not very surprising. I feel as though most students who go into any science field have an extreme interest in independent research to begin with. I am also not very surprised by the second value being field training since most geology training involves the outdoors. Most geologists I have met are outdoors people to begin with, so it is no surprise to me that they valued being outdoors doing what they loved. I was surprised by the third value of writing, although I am glad it made the list.  I guess I was surprised by this value because I feel like I did more writing in other classes such as chemistry, biology, and physics in the way of lab reports.

This article, of course, started to make me think what I valued in my geoscience education. If I had to list three items they would be field experiences, independent research, and strong relationships with my professors. I listed field experiences because I love the outdoors, I was afforded the opportunity to visit amazing places around the world, and I consider myself a visual and hands on learner. I listed independent research because I was taught time management, critical thinking, patience, and perseverance through grant writing and my research. My final point was listed because I truly believe without my professor's friendships, advising, and teaching I would not be where I am today.

What is geology, and why do I have a passion

What is geology? To put simply, geology is the study of rocks. To add a little more meat on the bone, geology is the science that deals with earth's physical structure, history, and the processes that act on it. When you consider that definition, it means that geology can focus not only on the rocks, but also the biosphere, hydrosphere, and atmosphere.

Compared to the other sciences, it feels like geology has been an undervalued science. In popular culture Sheldon from Big Bang Theory commonly makes fun of geologists. Quite recently, there has been talk from politicians about not funding geology because they believe it is not a core science. That claim is ridiculous and clearly shows the ignorance of these politicians. Geology is applicable in many different parts of our society such as mineral, oil and gas exploration. These are raw materials that are made into products you touch everyday whether you know it or not such as gasoline, lubricants, metals and even makeup.

Geology and other science disciplines often complement each other. Although you can probably make this claim for other sciences, I still love the fact that a good geologist has knowledge in many other fields. Here I will list different disciplines that are often incorporated with geology.

Geology - Biology = Palentology and ichnology
Geology - Chemistry = Geochemistry
Geology - Physics = Geophysics
Geology - Fluid mechanics = Sedimentology
Geology - Solid mechanics = Structural geology
Geology - Planetary Science = Planetary geology
Geology - Environmental sciences = Environmental geology

There are definitely a lot more sciences or sub-disciplines you can combine with geology. What I love about all the sub-disciplines in geology that I listed is that they are all actually pretty common. I went to school and/or are friends with colleagues who have studied these disciplines. I have a friend who studied geophysics on Mars!!! That is pretty cool!

I have a passion for geology because I find it fascinating that I can touch an object that is hundreds of millions of years old. When I touch a dinosaur bone, I have touched a part of a living creature that is maybe 65 million years old and we have nothing on Earth similar to it anymore. This animal walked around that location feeding on plants or other animals. That animal then died, decomposed, bones transported and buried to finally become fossilized. Those bones existed on Earth for millions of years when the Earth and the animals on it changed drastically. When I uncover this bone, I am the first one to see it in millions of years! Another example is walking around and finding ripples on a sandstone in the middle of Utah. These ripples are exactly like the ripples I would find on a beach on the east coast of the United States, but it is in a rock in the middle of a continent! What this rock is telling me is that water in an ocean or sea moved over this surface perhaps millions of years ago!

To summarize, I have a passion for geology because I get to touch, visualize, and try to interpret what was happening in this environment in the ancient past! Every rock tells a story, and I enjoy trying to interpret and write down this story.

Looking for faults

When I was thinking about creating a blog, I didn't want to blog about my personal life, my struggles, or my life decisions. There is nothing wrong with blogging about these topics, I just wanted to write and share my thoughts and ideas on a topic that I love. In case you came to this blog hoping to learn about my personal life, you are in luck today with this blog post.

So this past week my wife and I have put an offer into a house in Beaumont, TX where we will be moving for her job. We are very excited about this next step in our lives, but before we go through and finalize the purchase, diligent work needs to be done. The work I am talking about of course is the inspection of the house. We are having a hired professional inspect the house for any major repairs that may need to be done. As a geologist I am really interested in the ground the foundation and house is built on. 

This past week I went on an internet adventure trying to find geologic maps of the Beaumont area as well as a fault map. The last thing I want is a house we buy to be located on a fault that could potentially cause damage. The internet did not let me down. I found a couple very cool sites that showed the geology of the entire state of Texas! I will share one of those sites with you here: http://txpub.usgs.gov/DSS/texasgeology/.  

What I like about this site is you can zoom in and out really far and the geology is overlying a map of Texas so it is easier to see road and town names. In the top right corner of the website you can also turn on and off different features such as rock units, members, and faults. What doesn't thrill me about this site is the lack of identification of the units. The units are all abbreviated so it is difficult to know what they mean. What you can do is Google those abbreviations and you should get an answer to what units are. 

This next site is similar in that they have scanned individual areas of Texas. I like this site because they also include the legends for the individual maps.  http://www.twdb.texas.gov/groundwater/aquifer/GAT/.

The answer to my initial question about is my potential house going to be on faults appears to be no!  Now of course you shouldn't substitute a professional with looking at a map for yourself to identity potential problems. What I believe these maps can do are help you get an idea if you do live near identified faults that you may want to get more information on. 

I want to discuss just a little bit about the faulting in Houston. From what I have gathered the faults of Houston are thought to have developed with the formation of the Gulf of Mexico. The faults are considered growth faults, which is a type of normal fault that develops because of extensional forces (pulling apart). The down-dropped side of the faults are towards the basin (Gulf of Mexico). These faults are not like the faults in California that cause major earthquakes. These faults do however move at a rate of <1 to 3 cm a year depending on the fault and location.  

If you are interested in reading more about faults in the Houston area follow these links:

https://www.researchgate.net/publication/237842253_Lidar_mapping_of_faults_in_Houston_Texas_USA

http://pubs.usgs.gov/mf-maps/mf1136/mf1136/discuss.htm