Showing posts with label elevation. Show all posts
Showing posts with label elevation. Show all posts

Tuesday, October 17, 2023

The Cyclopean Wall: Why the salient?

In Simpson [1981] we read the following 

"The wall ... is sited wherever possible in such a manner as to force attackers from the north to approach over steeply  sloping ground.  Indeed a very wide (and expensive) loop was made in the central part of its preserved length ..., adding about 2 kilometres of "extra" walling, obviously in order  to maintain the desired elevation and to take advantage of the steep slopes." [1]

Dr. Simpson is quite mistaken about this.  Section Pe does sit on the top north edge of the Mytika plateau but segment Sp, the very next segment and some 230 m to the S of Pe, sits some 26 m. below the top of the ridge.  In 230 m, therefore, this 'defensive' wall has descended the height of an 8-story building from Pe.  That is clear in the next picture:


Segments Pe, Sp, and Zo.  Facing SE.
The blue 'fence' is a reconstruction of the route of the supposed wall.


The descent from Pe to Sp is clear in this picture.  The fact that a steep ridge sits immediately behind and above Sp and that Sp is actually embedded in the ridge makes it impossible that this segment was ever part of a defensive wall.  

Segment Sp.  A steep ridge (in which Sp is embedded) rises just behind
and makes it impossible to defend.

The very next segment, Zo, is at the same elevation as Sp but, because of the ground, sits on a level plain easily approachable to any 'attacker' coming up the valley.  

Simpson is correct that the southern salient (and the extra 1800 m of walling) requires an explanation.  An attempt 'to maintain the desired elevation and to take advantage of the steep slopes' is not that explanation.

Footnotes

[1] Simpson [1981] 35, 'A 61 Isthmia'.


Bibliography

Simpson [1981] : Simpson, Richard Hope. Mycenaean Greece.  Noyes  Press.  1981. ISBN: 0-8155-5061-8.

Wednesday, July 4, 2018

On Helladic.info: New Elevation Analysis and Gazetteer Report


I have always wanted this site to provide more than maps showing Mycenaean sites.  

Therefore I am happy to announce the release of new software for the site Helladic.info which provides more detailed reports and which I hope the community will find useful.

Additional text  has been placed on the 'Using the Atlas' page that explains what these reports do and how to access them.  

This blog entry is intended to familiarize users with these new pages and how they work.

The report page can be triggered both from the Controls Page Combo Map Box as well as the Combination Map itself. 



When, from the Controls page, you select some criterion such as the region name ‘Salamis’ you can then click on the new ‘Report’ button.

Choosing Reports from the original Controls page.  Select one, two or
three criteria (region, type, or ceramic horizon) and click on the new 'Report' button.




You can also reach the new reports pages from the Combination Map page by pressing the new report button.  The reporting criteria will be those that you selected when generating the map.

Main Report Page


The resulting REPORT page characterizes the sites which fit your criteria.

It provides a site breakdown by the number of times sites fitting your criteria are tagged with specific types. This gives you an idea of the dominant use of your chosen sites. There is also a site breakdown by regions. In this example using ‘Salamis’ all the sites are in that region and no other.



If you selected some criterion other than region you will get a table that lists all the regions containing sites that fit that criterion. For example if you chose the type ‘Fort’ the table would show all the regions that contain a site typed as ‘Fort’. Here those include ‘Boeotia’, ‘Thessaly’, ‘Corinthia’, ‘Locris Opuntia’, ‘Argolid’, and ‘Achaea’.



The basic REPORT page also has two buttons, ‘Elevation’ and ‘Gazetteer’ that, when clicked, will provide more detailed reports.

Close-up view of the detailed reports buttons.


The Gazetteer Report button provides a basic interative list of all the sites that fit your criterion. Clicking the Elevation report button provides further analysis of the elevations of the sites fitting your criterion.

ELEVATION REPORT


The elevation report provides several sections. The first is for basic statistical parameters.

Sample appearance of the parameters section of the Elevation Report.
In this case for Achaea.

 The parameters listed here are:

- Arithmetic mean of elevations of the sites that fit this criterion. This is the sum of the elevations divided by the number of sites.

- Median elevation. The median is another measure of central tendency. It is that actual elevation which falls halfway between the lowest and the highest elevations.

- Standard deviation

- Variance

- Skew The skew shows how much the bulk of the observations are displaced from the arithmetic mean. It is an indication of symmetry in the curve – or the lack of it. If the skew is positive then the bulk of the observations are displaced to the left of the mean; if negative then the bulk of the observations are displaced to the right of the mean. If the skew is 0.0 or close to it then the distribution is more or less symmetrical. Skew might be either positive or negative but in interpreting the meaning of any partiular skew I use the absolute value. So the skew parameter is interpreted as follows:

0.0: The distribution is symmetrical

0.0 to 0.5: The distribution is approximately symmetrical

0.5 to 1.0: The distribution is moderately skewed

> 1.0: The distribution is highly skewed

Kurtosis This is a parameter that indicates how much of the population is in the tails as opposed to the shoulders of the distribution. For more information about skew and kurtosis and how to interpret them see this.



The elevation report also provides two graphs. The first shows the frequency of various elevation ranges; that is, it maps the elevations into the frequency domain. The horizontal axis is elevations from 0 to highest elevation in the set. The vertical axis shows the frequency of sites whose elevations are in that range.

The second graph is a straight-forward plot of sites against their elevations in the order of increasing elevation. The horizontal axis consists of the site place keys in order of elevation from lowest to highest. The vertical axis is elevations.

Charts on the elevation report page.
Here for sites in Arcadia

Beneath the charts are two tables. The left-most table is a list of all the sites fitting these criteria which have elevations lower than the arithmetic mean. The right-most table is a list of all the sites fitting these criteria which have elevations greater than the arithmetic mean. The columns in both tables are sortable. The place key numbers in those tables, when clicked, will bring up a place key report for that site.

The next illustration shows the full elevation report page.



GAZETTEER

The Gazetteer report is a simple list of all the sites which meet the specified criteria. The criteria themselves are listed on the top of the page. A sortable and clickable list of all the relevant sites follows this. The list is sortable by clicking on the column heads.

Gazetteer Report Page


On the both the elevation and the gazetteer pages there are buttons for generating .kml and .csv files.  These will be implemented shortly.




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If you'd like to have a copy of the Mycenaean Atlas database then e-mail me and tell me about your project.  And remember that useful .kml and/or .csv files can be generated directly from all the windows (except the new reports pages) of the website helladic.info   Try it out! 



Blog Posts Concerning the Isthmian Wall

Since 2023 a number of posts concerning the Isthmian Wall and how we located its remaining segments, have appeared on this blog.  This post ...