A message from our CEO about the future of Stack Overflow and Stack Exchange. Read now.
46

I am an archaeologist and I specialize in the ancient Maya. Here's how it happens: 1: The vast majority of ancient Maya buildings are built using a "core and veneer" technique. The bulk of the building's volume is earth and stone rubble, faced with a veneer of nicely-shaped limestone blocks that are themselves covered by a layer of lime plaster (stucco). ...


15

The accumulation of soil in such situations takes a long time. The main way soil would have been naturally transported there would be by the wind. The wind blown soil would get caught and accumulate. Plants, particularly grasses, would grow on the soil and the plant roots would create mesh that would protect the soil from erosion. You are correct in that ...


4

Most of the Mexican pyramids are less steep than their Egyptian counterparts, and have niches and terraces which their Egyptian counterparts don't. An important difference is the climate, which is much damper in Mexico, and shows how the rainforest can reclaim areas where it has been eradicated if the site is then abandoned. Yet another factor is the type of ...


4

Your understanding is inaccurate. The shifts by $\frac{1^\circ}{24}$ are only relevant for figuring out, where the pixel centers are located and where to start when you are looking to find the right grid index for a certain point. As for the resolution, it is much simpler. We have $4320$ pixels covering $360^\circ$ in longitude direction, i.e. a resolution ...


3

These are terracettes https://en.wikipedia.org/wiki/Terracette#targetText=In%20geomorphology%2C%20a%20terracette%20is,them%20to%20move%20slowly%20downhill These are caused by natural earth movements as the slope angle is beyond the natural resting angle of the soil. These slopes are a result of rapid erosion e.g. by rivers and glaciers. Solifluction https:/...


3

Your photo doesn't show the strip of autumn-coloured trees very well; without your description I would have taken it for a strip of bare earth. All sorts of things could account for the autumn shades, there are too many unknowns to give a definite answer. We don't know whether the red-leaved trees are the same species as the others, for example. I ...


3

This book is based on Australian experience, some of it may be relevant of North American wildfires. I read it ten years ago. Paul Collins, Burn - The Epic Story of Bushfire in Australia, Allen & Unwin, 2006, ISBN 9781741750539, ISBN 1 74175 053 9. Part 4, titled: The Great Fire Debates, has three chapters (9 to 11); 09 To burn or not to burn 10 ...


3

You have two options ice segregation/frost heaving or humans screwing around. Frost heave can produce some really unusual yet regular shapes, spirals included. Frost heave and ice segregation is when freezing ground water pushes more on larger rocks sorting them out of finer material. Humans messing around can leave spirals intentionally (crop circles, ...


2

Disclaimer: this answer is based on what I remember from school and TV. When a volcano erupts with lava flows, the magma cools and forms an inhospitable, sterile surface. The first life to colonise the rocky surface is lichens. When the lichens start dying, they decay into very thin soil layers. Next comes moss which needs a tiny bit of soil. The roots of ...


2

As noted in the comments, this is actually a much more complex question than it might seem at first. Answering fully would require a very involved and technical discussion of single-beam surveying's inherent errors and their causes (water velocity, side slope reflection, highly transmissive hydrocarbon-rich anthropocene silt, and other such complications). I ...


2

Given that it's a quarry then at a guess the grass is growing over areas that are cut into the bedrock more deeply than the non-grassed areas, this means that there is a trench that holds a little more soil and water than the relatively bare rock outside of the cuts like a cropmark but smaller and more extreme.


1

After given some information about the data source I have a simple answer. Since the underscores SW etc. represent the four pixels around the city center and all the pixels cover the same physical area, taking a mean of the values will represent the average NDVI of the total area. It is all about what you will do with the NDVI data. E.g. if something ...


Only top voted, non community-wiki answers of a minimum length are eligible