Five Things: Portions of the South End at Higher Risk During Earthquakes

1. Partly sunny skies today with a chance of showers and thunderstorms in the afternoon. Humid with highs in the lower 80s.

2. Just as soon as folks figured out that they were not, in fact, crazy, and that they did, in fact, on Tuesday, the Metropolitan Area Planning Council put out a notice about how parts of the city are at risk should a "big one" ever hit.

During an earthquake, something called "liquefication" can happen. Basically this means certain kinds of materials are absorbed into the ground, making the land unstable. Because so much of Boston and the South End is built on filled-in tide flats and wetlands, liquefication poses a special danger in these parts. Everything in red on the map attached to this article is built on filled land.

3. Do you have something to say about the future of the Boston Public Library system? The library is holding a series of round table discussions to hear from the community on how to chart its future, systemwide. The next discussion is tonight at Parker Hill Branch in Roxbury, 1497 Tremont St., from 6 - 7 p.m.

4. The Boston Police Department has posted some fascinating historical photos on its website. Take a look at the old-fashioned motorcycle unit and helmets from 1890.

5. In more current BPD news, find answers to all your questions in the department's FAQ section. The updated piece explains how tips are kept anonymous and how to collect cash rewards for tips that lead to arrests.