"Place, with a trace of humanity" Photography/Photo of the Day/Pittsburgh

Posts tagged “navigation

Mapping the Ocean Floor

Meet Peter Holmberg Physical Scientist. This blog post is a collaborative effort.

Peter was in the middle seat between Mary and me on the plane(my sister likes the aisle, I like the window) from Seattle to Anchorage.

I said he’d be a great subject for my People at Work Series.



I’m going to let him tell you what he does…..

“I work at NOAA’s Pacific Hydrographic Branch as a Lead Physical Scientist.
My job entails mapping the ocean floor and compiling the data to nautical charts.
We use multibeam and side scan sonar for measuring depth and object (like ship wrecks) detection.
Data are processed (tides application, vessel motion correction etc) then refined and generalized to a usable scale on nautical charts as depths, contours and features.  
The link to Office of Coast Survey where you can view or download nautical charts.

Here is a video which is the embodiment of how we use multibeam sonar data to map the ocean floor.  Though this is a laser sensor projected onto sand instead of a sonar bouncing sound off the ocean floor.”


Thanks Peter.  It was so great to meet you. Thanks for writing back with the correct details about your work.  I thought the black and white version made it feel more “seriously scientific”😉


My Maps App Took Me Here to Cross the Mon?

(I think I read somewhere-  don’t use alliteration?  Mmmmmmmmm.)

How did I end up here, looking to cross the Mon?

I couldn’t believe it when I landed right in front of this sign. Bridge Closed.  It was just getting dark.

Turns out this bridge to Donora has been closed since 2009!!! The way you have to go now is a four mile addition to the trip.

The Monongahela River winds all around the place.  I’d crossed it at Homestead at the beginning of my journey.

Then I found out later this bridge is slated to be demolished.

With the help of my son’s MIL, Marlene, on the phone in Hardy, Virginia,  I found the Monessen Bridge and wound around  and up and over  to Donora.

You can’t always trust your Maps App.  At least the sign didn’t say BRIDGE OUT!    It was one of three routes.  Better try a different one next time. I read about the major supports having deteriorated.  Maybe the maps app just wanted to show me it for a photo op?

Took this right out of the passenger window

Took this right out of the passenger window