Tuesday is Books & Libraries Day at the River Houses. This week, take a few minutes from your homeschool schedule and explore the deepest depths of the ocean (by way of the Library of Congress).
All libraries, even the smallest, have a section devoted to maps and atlases. In a little town library it may only be a few shelves or a separate case set aside to hold large folio-sized books; that’s where you’ll usually find the library’s copy of the National Geographic atlas that we recommend to all homeschooling families (riverhouses.org/books). In a large city or university library the map and atlas section may be a separate room, and in the largest libraries whole departments are devoted to the collection and study of geographical reference materials.
The Library of Congress—our national library in the United States—has one of the largest map and atlas collections in the world, and the Map Division’s blog, “Worlds Revealed,” has just posted a beautiful account of the charting of the lowest point on earth:
- WORLDS REVEALED · Extremities of the Earth: The Lowest Natural Point (blogs.loc.gov/maps/2018/01/extremities-of-the-earth-the-lowest-natural-point)
It wasn’t until the 1870s that oceanographers began to develop a generally accurate sense of the true depth of the ocean in different parts of the world, and it was the expedition of the British research ship Challenger that discovered the area now called the Challenger Deep in the southwest Pacific near the island of Guam.
Spend a few minutes with your homeschool students this week exploring the beautiful map images that the Library of Congress has gathered of this lowest point on earth. And get out your recommended River Houses atlas for comparison: plate 115 illustrates the whole of the Pacific ocean floor, and right there, a little southwest of Guam, you’ll find the Challenger Deep named, at a depth (according to modern instruments) of 35,827 feet—almost 6.8 miles below the surface.
¶ Learning the library: Teaching your students how to use the library makes them independent learners. In today’s example, you’ll find the Challenger Deep in section K6 of plate 115 in the tenth edition of the comprehensive National Geographic Atlas of the World, the edition we recommend for homeschoolers (riverhouses.org/books). Do your students know how to locate a specific reference like that: “section K6 of plate 115”? Spend a few minutes teaching them (with any atlas) that the full-page map spreads are typically called plates and they are numbered in sequence (and the plate numbers don’t necessarily correspond to page numbers). The individual plates are labeled along the top and bottom edges with numbers and along the left and right edges with letters, so to find section K6 just locate the K row along the left side, and see where it crosses column 6. That will take you right to your target! This mode of reference is common in many atlases, and knowing how to use it is an important skill for your young library students to learn.
What have you discovered at your library lately?