Main page| FAQ's| Notes and Comments| References| Short loading course | OSO homepage | RSS homepage

Welcome to the free ocean tide loading provider

Skip intro


April 25, 2021: New model EOT20
(Hart-Davis et al., DGFI, doi=10.17882/79489)
July 12, 2021: Problems have been found recently. A revised version has been installed today at 10:00 UTC. Please resend your requests issued before this date.

August 9, 2020: Error in GOT4.10c with centre of mass option
Tides Q1 and K2 had erroneous coefficients for centre of mass.
Please resubmit your sites if you have used this combination of options.

June 26, 2020: New model TPXO.9.2a

March 7, 2020: Error in our copies of GOT4.10c, Q1 and K2 amplitudes, corrected.
For high-precision applications, the set of loading coefficients should be recomputed.

January 6, 2019: New model TPXO.9-Atlas
A high-resolution model, 30x30 cells per square-degree. Loading jobs are carried out at SEGAL at UBI/IDL in Portugal.
February 05, 2018: Alternative loading Greens function available
For decades the load convolution used an elastic Greens function ased on the Gutenberg-Bullen earth model. You can choose an alternative, a Green's function for an anelastic Earth based on PREM assuming a flat Q-factor spectrum. We call it STW105. It has been computed with Machiel Bos' program Astyanax. Presently, the PREM option is not available yet with ocean models FES2014b, FES2012 and TPXO8-Atlas; we are working on it. Further reading: Bos and Scherneck (2013)
February 05, 2018: A pro-memoriam on BLQ files (updated)
with emphasis on phase and its conversion for reckoning with respect to the local solid earth tide.
February 05, 2018: Revision of service for gravity and tilt
Today the service goes official with tilt parameters. We had to bring scaling and signs at both computing sites into consistency first. Still, please read the header information in the result mail carefully!
We kindly urge all users who used our service for tilt before Feb. 05, 2018, to issue their requests again.
February 05, 2018: Revised version of converter script for BLQ to TSOFT and g-Software (Micro'g Lacoste),
We offer a converter script (in perl v.5.8.8).
Caution, this is still a beta-version!
To run it under MS Windows, read here.
Please issue -h  for usage.
December 24, 2017: Grids
Global grids of ocean tide loading displacements in netCDF-format and medium resolution are now available. Please read the instructions presented when you follow the link. Feedback is highly welcome. The new set is provided as-is, no service is included except the promise that we inform those users that left us a note of updates and bug reports.
Machiel Bos and HGS are currently working towards augmenting the Loading Provider with a new set of high-resolution grids, much more actual and user-friendly, we hope. Goal: Ready in the first quarter of 2018.

(old news)


With the growing number of precise geodetic observations, the requests for ocean tide loading values have increased considerably. Therefore, this webpage has been created in the hope it will help the geodetic community. Just select an ocean tide model, tick the required type of loading, fill in the coordinates of the stations, give your e-mail address and press the submit button. The program will check if it can read your input and if so, it will calculate the values and send the results to you by e-mail. The program will take about 5 minutes per station. An example of the output in normal BLQ-formal can be found here while an example of the output in the new HARPOS-format can be found here .

If you find it tiresome to go through our web interface, you can send email to the loading provider in a special format.

Select ocean tide model

A brief description of the ocean tide models can be found here. Note: Default model is a fake to bar spammers

What type of loading phenomenon do you consider
vertical and horizontal displacements
gravity nm/s2 and tilt nrad

using Greens function
elastic (Farrell, 1972)
visco-elastic (STW105)

If you have selected vertical and horizontal displacements, you can correct for the centre of mass motion of the Earth due to the ocean tides . ( NO   means your frame origin is in the solid earth centre, YES  that it is in the joint mass centre of solid earth and ocean.)
Do you want to correct your loading values for the motion?

Want a plot? (New feature of Sep. 4, 2011)
The plots show the near-field resolution of the coastline. They are generated for each site that involves the loading post-processor OLMPP. Compare with the comment information in the result file.
Fetch it here after you received the results. Look for your user name: name-olmpp1.png name-olmpp2.png etc.

What kind of output format is required?
 BLQ (normal) 

Gravity loading parameters for TSOFT and g-Software can be converted from BLQ with

Where are your stations? 
In the following form up to one hundred stations can be entered but each station should be on a separate line. The height of the station above sea level is irrelevant for ocean tide load modelling of displacements: it is not necessary to input this parameter, it can be safely omitted.

Name of station_________| |Longitude (deg) | Latitude (deg) | Height (m)     OR
Name of station_________| X (m) Y (m) Z (m)

(Our fixed column layout: 24 characters for the station, 25'th column blank, then three numerical fields with a width of 16 characters each, no TAB characters please!)

What is your e-mail address?

Note: Because of a large amount of misuse we deny requests with return addresses at a couple of notorious domains.

No reply?
If you do not get a reply within a few hours, please have a look at our why-not criteria and (un-)common errors and
check that you have supplied a correct email-address.
Your job may be in the queue. Have a look here, it's updated every minute.
If you find the results useful, please cite this website mentioning the names M.S. Bos and H.-G. Scherneck. 

The 20-m VLBI telescope

Last updated: July 27, 2011
Send comments or questions to Hans-Georg Scherneck, hgs kanelbulle