LDEO Seismology: Long-Period Noise

542A-TA , LHN

Noise Levels at Different Periods

The table below gives the decibel 10% noise level (in db) for each month in several period bands. The 10% noise level is defined as the signal level not exceeded 10% of the time, based on hourly measurements. Each entry in the table is color coded with reference to the New Low Noise Model (NLNM, Peterson, 1993):
navy, -6 db < value-NLNM < -3 db
blue, -3 db < value-NLNM < 3 db
aqua, 3 db < value-NLNM < 6 db
lime, 6 db < value-NLNM < 9 db
yellow, 9 db < value-NLNM < 12 db
orange, 12 db < value-NLNM < 15 db
red, 15 db < value-NLNM < 20 db
fuchsia, 20 db < value-NLNM < 25 db
silver, value-NLNM < -6 db, value-NLNM > 25 db

Black indicates that there was an insufficient number of hourly measurements to calculate a noise level.

Noise levels (PSD) in decibels
Month Chan. Qual. # obs. 268s 228s 193s 164s 139s 118s 100s 85s 72s 61s 52s 44s 37s 32s 27s 23s 19s 16s 14s 12s 10s

201204 LHN AR 168 -144 -144 -146 -147 -147 -149 -150 -151 -151 -152 -153 -154 -155 -157 -156 -154 -148 -144 -142 -141 -143

201203 LHN AR 743 -141 -143 -144 -146 -147 -148 -149 -150 -151 -152 -153 -154 -155 -155 -155 -154 -150 -145 -143 -143 -139

201202 LHN AR 695 -137 -139 -140 -142 -143 -145 -146 -147 -149 -150 -150 -152 -152 -152 -152 -151 -147 -142 -140 -140 -137

201201 LHN AR 744 -137 -138 -139 -141 -143 -144 -145 -146 -148 -149 -150 -152 -153 -154 -154 -152 -146 -142 -140 -140 -137

201112 LHN AR 735 -137 -138 -140 -141 -142 -143 -145 -146 -147 -149 -150 -152 -153 -154 -155 -153 -147 -142 -139 -138 -136

201111 LHN AR 720 -137 -138 -140 -141 -142 -144 -145 -146 -147 -149 -150 -151 -152 -153 -152 -152 -146 -142 -140 -139 -137

201110 LHN AR 732 -137 -138 -139 -141 -143 -144 -145 -147 -149 -150 -152 -153 -154 -155 -156 -154 -149 -144 -142 -141 -141

201109 LHN AR 715 -135 -137 -138 -140 -142 -143 -145 -146 -148 -149 -151 -152 -153 -154 -155 -154 -150 -146 -143 -142 -141

201108 LHN AR 744 -133 -134 -136 -138 -139 -141 -143 -145 -146 -147 -149 -150 -151 -153 -153 -153 -150 -148 -148 -149 -144

201107 LHN AR 744 -137 -138 -140 -142 -143 -145 -146 -148 -149 -150 -152 -153 -154 -156 -156 -155 -152 -149 -149 -149 -145

201106 LHN AR 645 -137 -138 -140 -141 -143 -144 -146 -147 -148 -149 -151 -152 -153 -153 -154 -154 -151 -147 -148 -147 -142

201105 LHN AR 744 -136 -138 -139 -140 -142 -144 -144 -146 -146 -147 -148 -149 -150 -151 -151 -151 -149 -147 -146 -143 -142

201104 LHN AR 718 -137 -139 -140 -141 -143 -144 -145 -146 -146 -147 -148 -149 -150 -150 -150 -150 -147 -144 -143 -142 -139

201103 LHN AR 743 -138 -139 -141 -142 -144 -145 -146 -147 -148 -149 -149 -150 -150 -150 -150 -149 -145 -141 -141 -140 -137

Month	Chan.	Qual.	# obs.	268s	228s	193s	164s	139s	118s	100s	85s	72s	61s	52s	44s	37s	32s	27s	23s	19s	16s	14s	12s	10s
201204	LHN	AR	168	-144	-144	-146	-147	-147	-149	-150	-151	-151	-152	-153	-154	-155	-157	-156	-154	-148	-144	-142	-141	-143
201203	LHN	AR	743	-141	-143	-144	-146	-147	-148	-149	-150	-151	-152	-153	-154	-155	-155	-155	-154	-150	-145	-143	-143	-139
201202	LHN	AR	695	-137	-139	-140	-142	-143	-145	-146	-147	-149	-150	-150	-152	-152	-152	-152	-151	-147	-142	-140	-140	-137
201201	LHN	AR	744	-137	-138	-139	-141	-143	-144	-145	-146	-148	-149	-150	-152	-153	-154	-154	-152	-146	-142	-140	-140	-137
201112	LHN	AR	735	-137	-138	-140	-141	-142	-143	-145	-146	-147	-149	-150	-152	-153	-154	-155	-153	-147	-142	-139	-138	-136
201111	LHN	AR	720	-137	-138	-140	-141	-142	-144	-145	-146	-147	-149	-150	-151	-152	-153	-152	-152	-146	-142	-140	-139	-137
201110	LHN	AR	732	-137	-138	-139	-141	-143	-144	-145	-147	-149	-150	-152	-153	-154	-155	-156	-154	-149	-144	-142	-141	-141
201109	LHN	AR	715	-135	-137	-138	-140	-142	-143	-145	-146	-148	-149	-151	-152	-153	-154	-155	-154	-150	-146	-143	-142	-141
201108	LHN	AR	744	-133	-134	-136	-138	-139	-141	-143	-145	-146	-147	-149	-150	-151	-153	-153	-153	-150	-148	-148	-149	-144
201107	LHN	AR	744	-137	-138	-140	-142	-143	-145	-146	-148	-149	-150	-152	-153	-154	-156	-156	-155	-152	-149	-149	-149	-145
201106	LHN	AR	645	-137	-138	-140	-141	-143	-144	-146	-147	-148	-149	-151	-152	-153	-153	-154	-154	-151	-147	-148	-147	-142
201105	LHN	AR	744	-136	-138	-139	-140	-142	-144	-144	-146	-146	-147	-148	-149	-150	-151	-151	-151	-149	-147	-146	-143	-142
201104	LHN	AR	718	-137	-139	-140	-141	-143	-144	-145	-146	-146	-147	-148	-149	-150	-150	-150	-150	-147	-144	-143	-142	-139
201103	LHN	AR	743	-138	-139	-141	-142	-144	-145	-146	-147	-148	-149	-149	-150	-150	-150	-150	-149	-145	-141	-141	-140	-137