Add 100 km buffer of Alaska coastline

vector_data/polygon/CONTENTS.md

@@ -5,6 +5,7 @@ Brief descriptions of the polygon vector data found here. Unless otherwise noted
 ```
 polygon
 ├── boundaries
+│   ├── alaska_buffer
 │   ├── alaska_coast_simplified
 │   ├── alaska_hucs
 │   ├── climate_divisions
@@ -26,8 +27,12 @@ polygon
 ## `boundaries`
 Political or administrative boundaries including land ownership and management units, parks, refuges, fire management boundaries, ethnolinguistic regions, native corporations, and climate divisions.
 
+### `alaska_buffer`
+Dissolved 100 km buffer of the AK coastline (`alaska_coast_simplified`). Great for clipping raster data. EPSG:3338.
+
+
 ### `alaska_coast_simplified`
-Simplifed EPSG:3338 geometry of the otherwise complex and crenulated AK coastline. Great for clipping raster data. This is the go-to AK spatial boundary polygon.
+Simplifed EPSG:3338 geometry of the otherwise complex and crenulated AK coastline. Great for visualizing AK and for vector operations.
 
 ### `alaska_hucs`
 Alaska hydrologic units (i.e., watersheds) organized by HUC level (e.g. HUC-8) for Alaska.

vector_data/polygon/boundaries/alaska_buffer/alaska_100km_buffer.cpg

@@ -0,0 +1 @@
+UTF-8

vector_data/polygon/boundaries/alaska_buffer/alaska_100km_buffer.prj

@@ -0,0 +1 @@
+PROJCS["NAD_1983_Alaska_Albers",GEOGCS["GCS_North_American_1983",DATUM["D_North_American_1983",SPHEROID["GRS_1980",6378137.0,298.257222101]],PRIMEM["Greenwich",0.0],UNIT["Degree",0.0174532925199433]],PROJECTION["Albers"],PARAMETER["False_Easting",0.0],PARAMETER["False_Northing",0.0],PARAMETER["Central_Meridian",-154.0],PARAMETER["Standard_Parallel_1",55.0],PARAMETER["Standard_Parallel_2",65.0],PARAMETER["Latitude_Of_Origin",50.0],UNIT["Meter",1.0]]