Oldest-2 Array recovery (2023/9/17-10/14)
Day 28 (10/14):
Dear all,
We safely arrived at Anping port at 6pm and got off the ship.
Ban, Patty and Tong came to see us.
Best regards,
Kiyoshi
Day 20 (10/06):
Dear all,
The last ERI-OBS and OBEM came back safely at around the noon.
All ERI instruments were recovered. CTD was also conducted as planned.
All missions were done. We would like to thank all of you for your supports.
In the evening, we took a lot of group photos. I attach just one of them.
Now, Legend sails to the northwest.
We will pass through the north of Saipan and direct to Taiwan.
The ship's speed is around 9.5 knots.
If we can keep this speed, we will reach to Anping port on Oct. 14.
But we are afraid of a low pressure in our course.
Best regards,
Kiyoshi
Day 19 (10/05):
Dear all,
We successfully recovered an OBEM and an ERI-OBS at OL24 in the morning.
Although it was cloudy with short rain, the sea state was the best in this cruise.
The instruments were easily found and caught at the boardside relatively easily.
Then, we moved to OL27, which is the seismic-only site.
We released the OBS's anchor in the evening.
The acoustic response from the OBS was not clear and the flash light did not work again.
We found it relying only on the radio beacon and direction finder under the dark.
Next OL25 is the last observation site in this cruise.
We are trying to recover both OBEM and ERI-OBS, and CTD water sampling in the tomorrow morning.
Best regards,
Kiyoshi
Dear all,
Correction:
The sites we worked today were OL27 and OL26. I am sorry about this.
Best,
Kiyoshi
Day 18 (10/04):
Dear all,
At OL23, we successfully recovered an OBEM and conducted water sampling by CTD in the very early morning.
Then, we moved to OL24 and arrived at there at 2:40 pm.
At this site, both OBS and OBEM came up to the surface in immediately front of Legend.
The distance is about several tens meters.
We saw that the flash light mounted on the OBS started working in the water,
and in a few seconds, the OBS popped up.
This flash light stopped working just before the OBS was caught at the boardside.
We were lucky because the radio beacon did not work, neither, for this OBS.
Next site is OL27. We will reach to there tomorrow 4 am.
Best regards,
Kiyoshi
Day 17 (10/03):
Dear all,
We arrived at OL22 at around 6:30 am and recovered the fifth ERI-OBS and sixth OBEM.
Once OBS and OBEM are hoisted on deck, they are washed by fresh water, deconstructed, and lashed.
Some parts are maintained in the lab.
Now the role division is established very well and everyone works smoothly and quickly.
We finished the deck work just before squall.
We are moving to the east for OL23. Legend slows down in this direction.
The ETA is about 20 minutes before 11 pm. We have no OBS recovery at this site.
We will try to recover OBEM and sample water by CTD.
Best regards,
Kiyoshi
Day 16 (10/02):
Dear all,
The OBEM and ERI-OBS were successfully recovered at OL18 in the morning.
The OBS was hoisted up on the deck at sunrise.
The OBEM recovered was the fifth one. The half of the OBEMs are back to us now.
Then, we moved to OL21 and arrived at there after dinner.
This is one of the two seismic-only sites.
We recovered the fourth ERI-OBS under the moon.
Accidents happened to some small birds.
They hit the glass of the bridge and were laid on the pathway. Someone rescued them.
Next site is OL22. We will reach to there at around 6 am on Oct. 3.
Best regards,
Kiyoshi
Day 15 (10/01):
Dear all,
We recovered the third OBEM and first ERI-OBS at OL20 in the early morning.
The wind was bit strong and it took more time to catch the instruments but the recovery was done safely.
In the evening, we arrived at OL19. We tried to recover the OBEM and ERI-OBS.
When the OBS came up at the surface, it was dark already but neither the radio beacon nor the flush light worked.
Jim, a Ph.D student of National Central University, found the OBS when ship's search light swept the sea surface.
We finally recovered it. The OBEM was recovered successfully, too.
We are now moving to OL18. The ETA is 4:20 am. We will take short sleep.
Best,
Kiyoshi
Day 14 (9/30):
Dear all,
We successfully recovered the OBEM at OL16. The data look good.
But the IES OBS stayed at the seafloor. It did not ascend.
We arrived at OL17 at 1 pm and successfully recovered IES OBS and OBEM in the evening.
CTD was also done during the OBS is ascending.
The IES OBS team finished their mission.
They recovered three OBSs of the total five after all.
Now we are going to OL20.
Legend sails faster and smoothly when it directs to the south.
The muti-beam bathymetry data is beautiful.
We will arrive at the site at around 1 am on Oct. 1.
We will try to recover OBEM and ERI OBS.
Best regards,
Kiyoshi
Day 12 (9/28):
Dear all,
The sea state was good today.
We arrived at OL13 at 11:15 am and tried to recover the OBS as planed.
But we failed. The OBS did not respond at all.
The water sampling by CTD was done successfully.
We gave up recovering the OBEM at this site at 4 pm and directed Legend to the next site, OL14.
Now, Legend sails at 8.5 knots.
The ETA is tomorrow early in the morning, around 2 am.
Best regards,
Kiyoshi
Day 11 (9/27):
Dear all,
We are approaching to OL13, the northernmost site of the Oldest-2 array.
The ETA is around tomorrow noon (The ship's time zone is now UTC+10).
At this site, we will try to recover an IES OBS.
We will also try water sampling during waiting that the OBS comes up to the surface.
Although the wind speed is around 10 m/s at the present,
we hope it will calm down tomorrow.
Best regards,
Kiyoshi
Day 9 (9/25):
Dear all,
We got across the Philippine Sea and are now in the Pacific Ocean.
Because of strong headwind, Legend can sail at only around 6 knots for these days.
We are behind the original schedule.
Now ETA to the first point (OL13) is 28th evening.
Best regards,
Kiyoshi
Day 2 (9/18):
Dear all,
The sea state is very good so far.
R/V Legend is running smoothly to the east.
But the distance to the first recovery point (OL13) is more than 1600 nm.
We will have long transit. The estimate of arrival is 27th morning.
I may skip the report during the transit if there is nothing special.
Best regards,
Kiyoshi
Day 1 (9/17):
Dear all,
We took a group photo in front of R/V Legend in the morning.
After a brief meeting on the cruise and evacuation drill,
Legend cleared the port. Patty and Tong saw us off at the pier.
We are now passing through the southern margin of Taiwan pointing to the east.
Best regards,
Kiyoshi
Day 0 (9/16):
Dear all,
I report the Oldest-2 recovery cruise from today.
Our gears were shipped to Institute of Earth Science (IES),
Academia Sinica, Taiwan in August.
They were transported from IES to Anping port by a truck
together with those we left after the deployment cruise
and loaded on R/V Legend yesterday.
In this morning, Taiwanese and Japanese teams got on the ship.
We set up the equipments and tested them. Everything is fine.
We will depart the Anping port tomorrow morning.
Please cross your fingers for our safety and successful cruise.
Best regards,
Kiyoshi
