#2920: Survey Marker

XKCD comic, described below.
Transcript

[Zoomed in view of a round marker on the ground, with small specks of dirt around it. There is one line of text going around the central part in the outer rim of the marker, with the first three words written around the top, and the last two words written around the bottom (thus not text that are going all the way around in one single line). Inside this rim there are more text on three lines. In the center there is a small cross in a triangle pointing up in relation to the central text. There are more unreadable text below the last line of text and around the inner part of the rim. And off panel voice, which in the next panel turns out to be Cueball, is written above the mark.]

U.S. Geological Survey bench mark

Elevation above sea 447 feet

Cueball (off-panel): I love finding these survey markers. It's somehow reassuring.

[Cueball and Megan are shown as they look down on the marker. Cueball has one leg on either side of the marker and Megan stands to the right.]

Cueball: I like that someone, somewhere, knows where this spot is.

Cueball: If I stand on it, they know where I am.

[Cueball and Megan look up at each other.]

Megan: But the NAD83 and NAVD88 datums are getting replaced soon. That marker's coordinates could shift by like 5 feet.

[Megan is looking down at her phone in her hand, standing in the same place in relation to the marker. Cueball is now floating in the air behind her about 5 feet above the ground, while flailing with his arms and legs (as shown with three small curved lines at the end of either arm and above and below him).]

Megan: Oh look, it just got updated.

Cueball: Hey! Put me back!

(Sourced from explainxkcd.com)

Title text:Fun fact: The standard North American NAD83 coordinate system is misaligned from the actual Earth, off-center by about 7 feet. Someone knows where I am, and I'm in the wrong place.


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